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Comparison of Arterial Blood Gases of Laryngeal Mask Airway and Bag-Valve-Mask Ventilation in Out-of-Hospital Cardiac Arrests
Abstract
Background:
Focusing on the efficacy of successful ventilation during cardiopulmonary resuscitation (CPR) with alternative airways, previous reports investigated various parameters such as success rate, tidal volume, incidence of regurgitation, etc. However, there are few investigations of arterial blood gases (ABG) during CPR with alternative airways, especially the laryngeal mask airway (LMA).
Methods and results:
A prospective multicenter study, non-randomized control trial compared ABG on hospital admission of patients resuscitated by emergency medical service personnel with a bag-valve-mask (BVM) with those using a LMA in witnessed cardiac-verified out-of-hospital ventricular fibrillation (VF) or pulseless ventricular tachycardia. According to the Utstein template, 173 cases of LMA and 200 of BVM both placed by paramedics were enrolled. The median arterial pH was statistically higher in the LMA group than in the BVM group (7.117 vs 7.075, P=0.02). There was no difference in the median value of PaCO(2) (52.9 vs 55.3, P=0.06) and PaO(2) (64.6 vs 71.9, P=0.56).
Conclusions:
LMA does not greatly benefit the respiratory status of patients such as in this study population. Delayed placement of a LMA will be recommended to achieve minimally interrupted chest compression in an out-of-hospital CPR protocol for witnessed VF cases following shock.
... Most of ARDS patients present endothelial dysfunction comorbidities with increased pulmonary and systemic vascular resistances. A situation that most commonly worsen with conventional treatment such as vasopressors and steady-flow CADs like ECMO [21]. Yet, the immobilization of the respiratory pump and transformation of the respiratory tract into a closed pressurized hydraulic circuit by mechanical ventilators besides their interference with coronary perfusion flow are the principles causes of hemodynamic and metabolic deterioration in ARDS [21,22]. ...
... A situation that most commonly worsen with conventional treatment such as vasopressors and steady-flow CADs like ECMO [21]. Yet, the immobilization of the respiratory pump and transformation of the respiratory tract into a closed pressurized hydraulic circuit by mechanical ventilators besides their interference with coronary perfusion flow are the principles causes of hemodynamic and metabolic deterioration in ARDS [21,22]. ...
Rationale: Most critically ill Covid-19 patients succumb to multiple organ failure and / or cardiac arrest as a result of comorbid endothelial dysfunction disorders which had probably aggravated by conventional mechanical assist devices. Even worse, mechanical ventilators prevent the respiratory pump from performing its crucial function as a potential generator of endothelial shear stress (ESS) which controls microcirculation and hemodynamics since birth. The purpose of this work is to bring our experience with ESS enhancement and pulmonary vascular resistance (PVR) management as a potential therapeutic solution in acute respiratory distress syndrome (ARDS). We propose a noninvasive device composed of thoracic and infradiaphragmatic compartments that will be pulsated in an alternating frequency (20/40 bpm) with low-pressure pneumatic generator (0.1-0.5 bar). Oxygen supply, nasogastric ± endotracheal tubes are considered.
Proof-of-concept: prototypes were tested in pediatric models of refractory cardiac arrest (≥20min), showed restoration of hemodynamics (BP≥100 mm Hg) and urine output, regardless of heartbeats, pharmacological supports and mechanical ventilation.
Conclusions ESS enhancement represents a more effective treatment to increase tissue oxygenation and improve hemodynamic in ARDS. A cost-effective method which could be induced with a non-invasive pulsatile device adaptable to cardiopulmonary-circulatory biophysics to maintain a fully functional respiratory pump and avoid confrontation of the opposite hydraulic circuits.
... A prospective nonrandomized study of the SOS-KANTO group demonstrated that there was no greater benefit of respiratory status in patients resuscitated by emergency medical personnel with a bag-valvemask comparing to those resuscitated using a laryngeal mask (median value of PaCO 2 [52.9 vs 55.3, P=0.06] and PaO 2 [64.6 vs. 71.9, P=0.56]) in witnessed outof-hospital cardiac arrest (74). Interestingly, when the survival to hospital discharge was evaluated as a secondary endpoint, it was higher in the laryngeal mask airway group than in the bag-mask group (13.4% vs. 6.1%, ...
... Interestingly, when the survival to hospital discharge was evaluated as a secondary endpoint, it was higher in the laryngeal mask airway group than in the bag-mask group (13.4% vs. 6.1%, P=0.03) (73,74). ...
Despite advances in cardiac arrest care, the overall survival to hospital discharge remains poor. The objective of this paper was to review the innovations in cardiopulmonary resuscitation that could influence survival or change our understanding about cardiopulmonary resuscitation. We have performed a search in the MEDLINE and the Cochrane databases for randomized controlled trials, meta-analyses, expert reviews from December 2005 to March 2010 using the terms cardiac arrest, basic life support, and advanced life support. The lack of randomized trials during the last 5 years remains the main problem for crucial decisions in cardiopulmonary resuscitation. Current trends in cardiopulmonary resuscitation are toward minimizing the interruptions of chest compressions and improving the quality of cardiopulmonary resuscitation. In addition, attention should be paid to all the parts of chain of survival, which remains essential in improving survival rates.
... Several papers have been published from this registry. 10,[42][43][44][45] Notably, one publication showed that bystanderperformed CC-CPR was not inferior to conventional resuscitation in terms of neurological outcomes. 45 This finding has had significant implications and has contributed to advancements in CPR practices globally. ...
Aim
Out-of-hospital cardiac arrest (OHCA) is a life-threatening emergency with high mortality. The “chain of survival” is critical to improving patient outcomes. To develop and enhance this chain of survival, measuring and monitoring the resuscitation processes and outcomes are essential for quality assurance. In Japan, several OHCA registries have successfully been implemented at both local and national levels. We aimed to review and summarise the conception, strengths, and challenges of OHCA registries in Japan.
Method and results
The following representing registries in Japan were reviewed: the All-Japan Utstein registry, the Utstein Osaka Project/the Osaka-CRITICAL study, the SOS-KANTO study, the JAAM-OHCA study, and the SAVE-J II study. The All-Japan Utstein registry, operated by the Fire and Disaster Management Agency of Japan and one of the largest nationwide population-based registries in the world, collects data concerning all patients with OHCA in Japan, excluding in-hospital data. Other research- and hospital-based registries collect detailed out-of-hospital and in-hospital data. The Osaka-CRITICAL study and the SOS-KANTO study are organized at regional levels, and hospitals in the Osaka prefecture and in the Kanto area participate in these registries. The JAAM-OHCA study is managed by the Japanese Association of Acute Medicine and includes 107 hospitals throughout Japan. The Save-J II study focuses on patients with OHCA treated with extracorporeal cardiopulmonary resuscitation.
Conclusion
Each OHCA registry has its own philosophy, strengths, perspectives, and challenges; however, all have been successful in contributing to the improvement of emergency medical service (EMS) systems through the quality improvement process. These registries are expected to be further utilized to enhance EMS systems and improve outcomes for patients with OHCA, while also contributing to the field of resuscitation science.
... This may be worsened by suppressing the important role of the respiratory pump as a master-key circulatory driving force and a potential generator of ESS. As ventilators with endotracheal intubation and neuromuscular blockades transform the respiratory pump into a pressurized, immobilized hydraulic circuit, along with their interference with coronary perfusion flow [82,83]. ...
Sudden cardiac arrest (SCA) remains a major health issue worldwide with a gloomy outcome due to the inadequate organs’ perfusion during cardiopulmonary resuscitation (CPR). Alternatively, we aim through the present work to expose our visions of SCA management and propose a new technique of cardiac massage, urging CPR experts around the world to conduct their in-depth reviews for the sake of patients.
... Yet, the ugly fact is that the important role of the respiratory pump as a master-key circulatory driving force and a potential generator of ESS is still disregarded by therapists. As ventilators with endotracheal intubation and neuromuscular blockades transform the respiratory pump into a piston-like, closed, pressurized, immobilized, (purulent), hydraulic circuit, along with their interference with coronary perfusion flow are the principle causes of hemodynamic and metabolic deterioration in ARDS [17,18]. In addition, the extra-alveolar and alveolar endothelial cells of the fragile alveolar system are embryologically different, which promotes serious complications, such as insufficient inhalational pulmonary arterial hypertension (PAH) therapies, barotrauma, and most likely alveolar fibrosis [19,20]. ...
Most critically ill Covid-19 patients succumb to multiple organ failure and/or sudden cardiac arrest (SCA) as a result of comorbid endothelial dysfunction disorders which had probably aggravated by conventional mechanical assist devices. Even worse, mechanical ventilators prevent the respiratory pump from performing its crucial function as a potential generator of endothelial shear stress (ESS) which controls microcirculation and hemodynamics since birth. The purpose of this work is to bring our experience with ESS enhancement and pulmonary vascular resistance (PVR) management as a potential therapeutic solution in acute respiratory distress syndrome (ARDS). We propose a non-invasive device composed of thoracic and infradiaphragmatic compartments that will be pulsated in an alternating frequency (20/40 bpm) with low-pressure pneumatic generator (0.1–0.5 bar). Oxygen supply, nasogastric with, or without endotracheal tubes are considered.
... 27 A few studies that contradict these findings used more experienced providers, highlighting the need for experience and practice in order to ventilate with BMV effectively. 2,[28][29][30] EGDs are essential for emergency ventilation in patients who are known to have difficult mask ventilation, such as those with beards, morbid obesity, or a history of snoring. 6,7,27 In cardiac arrest patients, EGDs result in a lower incidence of gastric insufflation and regurgitation than BMV. ...
Introduction:
Bag mask ventilation (BMV) and extraglottic devices (EGDs) are two common methods of providing rescue ventilation. BMV can be difficult to perform effectively, especially for inexperienced providers and in patients with difficult airway characteristics. There is some evidence that the laryngeal tube (LT) can be successfully placed by inexperienced providers to provide effective ventilation. However, it is unclear whether ventilation provided by LT is superior to that of BMV, especially in the hands of inexperienced airway providers. Therefore, we aimed to compare ventilation efficacy of inexperienced airway providers with BMV versus LT by primarily measuring tidal volumes and secondarily measuring peak pressures on a simulated model.
Methods:
We performed a crossover study first year emergency medicine residents and third and fourth year medical students. After a brief instructional video followed by hands on practice, participants performed both techniques in random order on a simulated model for two minutes each. Returned tidal volumes and peak pressures were measured.
Results:
Twenty participants were enrolled and 1200 breaths were measured, 600 per technique. The median ventilation volumes were 194 milliliters (mL) for BMV, and 387 mL for the laryngeal tube, with a median absolute difference of 170 mL (95% confidence interval [CI] 157-182 mL) (mean difference 148 mL [95% CI, 138-158 mL], p<0.001). The median ventilation peak pressures were 23 centimeters of water (cm H2O) for BMV, and 30 cm H2O for the laryngeal tube, with a median absolute difference of 7 cm H2O (95% CI, 6-8 cm H2O) (mean difference 8 cm H2O [95% CI, 7-9 cm H2O], p<0.001).
Conclusion:
Inexperienced airway providers were able to provide higher ventilation volumes and peak pressures with the LT when compared to BMV in a manikin model. Inexperienced providers should consider using an LT when providing rescue ventilations in obtunded or hypoventilating patients without intact airway reflexes. Further study is required to understand whether these findings are generalizable to live patients.
... 106 Prior studies evaluating the use of a bag-valve-mask device during out-of-hospital cardiac arrest resuscitation demonstrated an association with improved survival and neurologic outcomes as compared to those managed with a supraglottic airway device or endotracheal intubation. 100,[107][108][109][110] However, these observational studies have been limited by confounding by indication and resuscitation time bias, as supraglottic airways are often placed after other airway management techniques have failed. Additionally, endotracheal intubation may be a surrogate for a prolonged resuscitation. ...
Out‐of‐hospital cardiac arrest continues to be a devastating condition despite advances in resuscitation care. Ensuring effective gas exchange must be weighed against the negative impact hyperventilation can have on cardiac physiology and survival. The goals of this narrative review are to evaluate the available evidence regarding the role of ventilation in out‐of‐hospital cardiac arrest resuscitation and to provide recommendations for future directions. Ensuring successful airway patency is fundamental for effective ventilation. The airway management approach should be based on professional skill level and the situation faced by rescuers. Evidence has explored the influence of different ventilation rates, tidal volumes, and strategies during out‐of‐hospital cardiac arrest; however, other modifiable factors affecting out‐of‐hospital cardiac arrest ventilation have limited supporting data. Researchers have begun to explore the impact of ventilation in adult out‐of‐hospital cardiac arrest outcomes, further stressing its importance in cardiac arrest resuscitation management. Capnography and thoracic impedance signals are used to measure ventilation rate, although these strategies have limitations. Existing technology fails to reliably measure real‐time clinical ventilation data, thereby limiting the ability to investigate optimal ventilation management. An essential step in advancing cardiac arrest care will be to develop techniques to accurately and reliably measure ventilation parameters. These devices should allow for immediate feedback for out‐of‐hospital practitioners, in a similar way to chest compression feedback. Once developed, new strategies can be established to guide out‐of‐hospital personnel on optimal ventilation practices.
... BVM ventilation is recommended by the 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care and the European Resuscitation Committee (30,31) when professionals perform early CPR on subjects with OHCA. With respect to bystander CPR with chest compression only, a prospective multicenter, non-randomized controlled trial SOS-KANTO (18) reported that the arterial potential of hydrogen (pH) of the extracorporeal ventricular fibrillation or pulseless ventricular tachycardia was higher in the LMA group than in the BVM group, but LMA was not as beneficial as BVM in improving the respiratory status of such subjects. A large study of 649,359 subjects in Japan with OHCA found that subjects with BVM had better neurological outcomes after 1 month than subjects with LMA or ETI, and this was thought to be related to the benefits of sustained chest compressions (32). ...
Background:
For subjects with out-of-hospital cardiac arrest (OHCA), bag-valve mask (BVM), endotracheal intubation (ETI), and laryngeal mask airway (LMA) are the most common methods of ventilatory support; however, the best choice remains controversial.
Methods:
A comprehensive search of online databases was performed. A traditional meta-analysis was performed to determine the risk ratio of BVM vs. LMA and ETI vs. LMA. Indirect treatment comparisons (ITCs) were conducted to compare BVM and ETI.
Results:
A total of 13 full-text articles reporting the efficacy of BVM, ETI, and LMA were considered in this analysis. BVM and LMA had the same effect regarding return of spontaneous circulation (ROSC) (23% vs. 24%; RR =0.84), survival rate at admission (19% vs. 21%; RR =0.82) or discharge (6% vs. 4%; RR =0.61). ETI was superior to LMA in terms of ROSC (48% vs. 23%; RR =0.72) and survival rate at both admission (27% vs. 19%; RR =0.85) and discharge (12% vs. 4%; RR =0.90). BVM was inferior to ETI in terms of ROSC (24% vs. 48%; RR =0.86), survival to admission rate (21% vs. 27%; RR =1.037), and survival to discharge rate (6% vs. 12%; RR =1.476).
Conclusions:
ETI should be considered for airway management as early as possible, which can improve the subject's success rate of recovery and survival to admission rate. In future, large-scale, multi-center, randomized controlled studies should be conducted to evaluate the exact efficacy of BVM, ETI, and LMA for the first aid of subjects with OHCA.
... AAM is only indicated in patients with confirmed cardiac or respiratory arrest. 15 In Japanese prehospital protocol patients with confirmed cardiac output on arrival to EMS are often treated with BVM ventilation. ...
Objectives:
Many registry studies on patients with out-of-hospital cardiac arrest (OHCA) have reported that conventional bag-valve-mask (BVM) ventilation is independently associated with favourable outcomes. This study aimed to compare the data of patients with OCHA with confirmed cardiac output on emergency medical services (EMS) arrival and consider the confounding factors in prehospital airway management studies.
Methods:
This was a cohort study using the registry data for survivors after out-of hospital cardiac arrest in the Kanto region at 2012 in Japan (SOS-KANTO 2012). Survivors who received advanced airway management (AAM) group and a BVM group were compared for confirmed cardiac output on EMS arrival and neurolgical outcome at 1 month. Favourable neurological outcome was defined as a score of one or two on the Cerebral Performance Categories Scale. Multivariable logistic regression was used to adjust the neurological outcome by age, gender, cardiac aetiology, witnessed arrest, shockable rhythm, cardiopulmonary resuscitation performed by a bystander, BVM at prehospital ventilation and presence of confirmed cardiac output on EMS arrival.
Results:
A total of 16 452 patients were enrolled in the SOS-KANTO 2012 study, and of those data 12 867 were analysed; 5893 patients comprised the AAM group and 6974 comprised the BVM group. Of the study participants, 386 (2.9%) had confirmed cardiac output on EMS arrival; 340 (2.6%) of the entire study group had a favourable neurological outcome. The proportion of patients with confirmed cardiac output on EMS arrival was significantly higher in the BVM group (272: 3.9%) than in the AAM group (114: 1.9%) (95% CI: 1.65 to 2.25). The proportion of patients with favourable neurological outcomes was 30% (117/386) in those with cardiac output on EMS arrival compared with 1.8% (223/12481) in those without. The OR for a good neurological outcome with BVM decreased from 3.24 (2.49 to 4.20) to 2.60 (1.97 to 3.44) when confirmed cardiac output on EMS arrival was added to the multivariable model analysis.
Conclusion:
Confirmed cardiac output on EMS arrival should be considered as confounding by indication in observational studies of prehospital airway management.
... (2) efficacy in maintaining oxygenation and ventilation; (3) frequency of complications (34). Using these criteria, the results of this study supports that orotracheal intubation is the preferred technique for ventilation during CPR in dogs. ...
The efficacy of ventilation of dogs during cardiopulmonary resuscitation (CPR) with a tight fitting face mask or mouth-to-nose rescue breathing has not been evaluated. Twenty-four purpose bred research dogs: Dogs were randomized to be ventilated by cuffed orotracheal tube, tight fitting face mask, mouth-to-nose breathing or compressions only during CPR (n = 6 in all groups). Orotracheal tube and face mask ventilation was performed on room air. Chest compressions were performed during the experimental procedure. Arterial blood gases were performed prior to euthanasia (baseline), at 3 min and at 6 min of CPR. PaO2 and PaCO2 were compared for each time point and each group. There was no difference in PaO2 or PaCO2 between groups at baseline. At 6 min all groups had a significantly higher PaCO2 (P ≤ 0.005) and the facemask and compression only groups had a significantly lower PaO2 (P < 0.02) when compared to the orotracheal tube group. There was no difference between the PaO2 of the mouth-to-nose group compared to the orotracheal tube group at 3 or 6 min. Gastric distension, regurgitation, gas leakage around the mouth, and ineffective breaths were all noted in both the face mask and mouth-to-nose group. The results of this study supports that orotracheal intubation is the preferred technique for ventilation during CPR in dogs. When orotracheal intubation is not possible, face mask ventilation or mouth-to-nose ventilation would be reasonable alternatives. When oxygen supplementation is available, face mask ventilation is likely to be superior. Appropriate training for both face mask and mouth-to-nose ventilation techniques is recommended.
... Besides, ECMO provides a steady-flow perfusion mode that promotes to endothelial dysfunction complications (50). Mechanical ventilation might promote hyperventilation that may interfere with hemodynamics and coronary perfusion flow (59,60). Also, ventilators could worsen patients' hemodynamics because of the suppression of the respiratory pump ESS. ...
Sudden cardiac arrest (SCA) remains a major problem for health authorities worldwide. Insufficiencies of current cardiopulmonary resuscitation (CPR) are most probably related to an inappropriate concept and applied methods that still concentrate on heartbeat as priority, instead of blood circulation to maintain organs' perfusions. The aim of this works is to propose a new therapeutic approach for SCA in a more effective and secure manner compared with current CPR methods. It correlates to a non-invasive circulatory flow restoration (CFR) device composed of a multilayered thoracic and infradiaphragmatic compartments that will be pulsated alternatively and in fixed frequencies using a low-pressure pneumatic generator. Proof-of-concept studies with different prototypes and methods of SCA, showed restoration of hemodynamics (BP ≥ 100 mm Hg) and increased urine output after 20 min of cardiac arrest in pediatric dogs and piglets. In summary, a CFR device can induce shear stress-mediated endothelial function to restore microcirculation and cellular metabolism. This represents a cost-effective method, predisposes to return of spontaneous circulation in case of SCA, adaptable for all age groups, in public and hospital environments.
... A avaliação objetiva da efetividade da ventilação pulmonar, realizada por meio do oxímetro de pulso, gasometria ou ETCO2, foi observada em quatro estudos (11,14,17,20) . p=0,56) (12) . O estudo descritivo que avaliou os resultados de 42 pacientes (84%) com ML mostrou valores médios de PO2 de 120 mmHg e PCO2 de 31,1 mmHg (17) . ...
O estudo teve como objetivo analisar a sobrevida, a efetividade da ventilação e a ocorrência de regurgitação associadas ao uso da máscara laríngea em paciente com parada cardiorrespiratória. Trata-se de revisão sistemática realizada nas bases de dados LILACS, Embase, CINAHL, MEDLINE e Cochrane. O total de estudos selecionados foi 13, sendo dois ensaios clínicos, um randomizado controlado e outro não randomizado, e 11 estudos descritivos. No ensaio clínico randomizado controlado, a sobrevida dos pacientes que utilizaram a máscara laríngea foi de 7%, mas não houve diferença estatística quando comparada aos outros dispositivos para via aérea. A ventilação pulmonar foi efetiva tanto na avaliação subjetiva quanto na objetiva. A regurgitação foi observada em três casos, mas a frequência não foi estatisticamente diferente dos demais grupos. Os resultados dos estudos desta revisão sistemática indicam a necessidade de realizar estudos controlados e randomizados para analisar os benefícios do uso da máscara laríngea na ressuscitação cardiorrespiratória.
... and recent data from patients arriving in the emergency department under ongoing CPR also showed blood gas variables which correspond well to our findings. 28 Surprisingly, although a metabolic component was present in many of the cases, hypercarbia contributed to a large part of the acidosis. The accumulation of acid metabolites does not seem to be a conditio sine qua non in the state of CPR, as it does not occur in all of the cases. ...
An arterial blood gas analysis (ABG) yields important diagnostic information in the management of cardiac arrest. This study evaluated ABG samples obtained during out-of-hospital cardiopulmonary resuscitation (OHCPR) in the setting of a prospective multicenter trial. We aimed to clarify prospectively the ABG characteristics during OHCPR, potential prognostic parameters and the ABG dynamics after return of spontaneous circulation (ROSC).
ABG samples were collected and instantly processed either under ongoing OHCPR performed according to current advanced life support guidelines or immediately after ROSC and data ware entered into a case report form along with standard CPR parameters.
During a 22-month observation period, 115 patients had an ABG analysis during OHCPR. In samples obtained under ongoing CPR, an acidosis was present in 98% of all cases, but was mostly of mixed hypercapnic and metabolic origin. Hypocapnia was present in only 6% of cases. There was a trend toward higher paO2 values in patients who reached sustained ROSC, and a multivariate regression analysis revealed age, initial rhythm, time from collapse to CPR initiation and the arterio-alveolar CO2 difference (AaDCO2) to be associated with sustained ROSC. ABG samples drawn immediately after ROSC demonstrated higher paO2 and unaltered pH and base excess levels compared with samples collected during ongoing CPR.
Our findings suggest that adequate ventilation and oxygenation deserve more research and clinical attention in the management of cardiac arrest and that oxygen uptake improves within minutes after ROSC. Hyperventilation resulting in arterial hypocapnia is not a major problem during OHCPR.
... A recent metaanalysis suggested that non-traumatic OHCA patients whose airways were treated with ETI had better outcomes than those treated with SADs [40]. Patient survival might not be an appropriate indicator for comparing different airway techniques used during cardiac arrest, however, since the outcome could be influenced by many factors [41]. ...
Background
Though airway management methods during out-of-hospital cardiac arrest (OHCA) remain controversial, no studies on the topic from Finland have examined adherence to OHCA recommendations in real life. In response, the aim of this study was to document the interventions, success rates, and adverse events in airway management processes in OHCA, as well as to analyse survival at hospital discharge and at follow-up a year later.
Methods
During a 6-month study period in 2010, data regarding all patients with OHCA and attempted resuscitation in southern and eastern Finland were prospectively collected. Emergency medical services (EMS) documented the airway techniques used and all adverse events related to the process. Study endpoints included the frequency of different techniques used, their success rates, methods used to verify the correct placement of the endotracheal tube, overall adverse events, and survival at hospital discharge and at follow-up a year later.
Results
A total of 614 patients were included in the study. The incidence of EMS-attempted resuscitation was determined to be 51/100,000 inhabitants per year. The final airway technique was endotracheal intubation (ETI) in 413 patients (67.3 %) and supraglottic airway device (SAD) in 188 patients (30.2 %). The overall success rate of ETI was 92.5 %, whereas that of SAD was 85.0 %. Adverse events were reported in 167 of the patients (27.2 %). Having a prehospital EMS physician on the scene (p < .001, OR 5.05, 95 % CI 2.94–8.68), having a primary shockable rhythm (p < .001, OR 5.23, 95 % CI 3.05–8.98), and being male (p = .049, OR 1.80, 95 % CI 1.00–3.22) were predictors for survival at hospital discharge.
Conclusions
This study showed acceptable ETI and SAD success rates among Finnish patients with OHCA. Adverse events related to airway management were observed in more than 25 % of patients, and overall survival was 17.8 % at hospital discharge and 14.0 % after 1 year.
... The survey of survivors after out-of-hospital cardiac arrest in the Kanto area of Japan (SOS-KANTO) was a prospective, multicenter observational trial consisting of 9,592 patients who suffered out-of-hospital cardiac arrest and were transported to the 58 emergency hospitals participating in the SOS-KANTO by emergency medical service personnel. 7- 10 The present study patients were enrolled from the SOS-KANTO trial when they met the following criteria: aged 18 years or older; persistent cardiac arrest on arrival at the emergency room (ER); asystole or PEA after the first administration of epinephrine in the ER. Exclusion criteria were a return of spontaneous circulation (ROSC) before the second administration of epinephrine, administration of vasopressin or high-dose epinephrine, extracorporeal CPR, documented terminal illness and the presence of a do-not-resuscitate order. ...
Background:
The 2005 guidelines for cardiopulmonary resuscitation (CPR) have recommended that administration of atropine can be considered for non-shockable rhythm, but there are insufficient data in humans.
Methods and results:
The effects of atropine were assessed in 7,448 adults with non-shockable rhythm from the SOS-KANTO study. The primary endpoint was a 30-day favorable neurological outcome after cardiac arrest. In the 6,419 adults with asystole, the epinephrine with atropine group (n=1,378) had a significantly higher return of spontaneous circulation (ROSC) rate than the epinephrine alone group (n=5,048) with an adjusted odds ratio of 1.6 (95% confidence interval (CI) 1.4-1.7, P<0.0001), but the 2 groups had similar 30-day favorable neurological outcome with an adjusted odds ratio of 0.6 (95%CI 0.2-1.7; P=0.37). In the 1,029 adults with pulseless electrical activity (PEA), the 2 groups had similar rates of ROSC and 30-day favorable neurological outcome, and the epinephrine with atropine group had a significantly lower 30-day survival rate than the epinephrine alone group with an adjusted odds ratio of 0.4 (95%CI 0.2-0.9, P=0.016).
Conclusions:
Administration of atropine had no long-term neurological benefit in adults with out-of-hospital cardiac arrest due to non-shockable rhythm. Atropine is not useful for adults with PEA.
... Ventilation through a variety of supraglottic devices results in similar arterial blood gas values, compared with traditional bagvalve-mask ventilation. 93,94 Additionally, ventilation through a laryngeal mask airway results in less regurgitation (3.5%) than ventilation with a bag-valve mask (12.4%). 95 Supraglottic airways perform as well as, or better than, endotracheal intubation in terms of insertion success, time to insertion, and ventilation parameters. ...
Cardiac arrest is a dynamic disease that tests the multitasking and leadership abilities of emergency physicians. Providers must simultaneously manage the logistics of resuscitation while searching for the cause of cardiac arrest. The astute clinician will also realize that he or she is orchestrating only one portion of a larger series of events, each of which directly affects patient outcomes. Resuscitation science is rapidly evolving, and emergency providers must be familiar with the latest evidence and controversies surrounding resuscitative techniques. This article reviews evidence, discusses controversies, and offers strategies to provide quality cardiac arrest resuscitation.
Copyright © 2015 Elsevier Inc. All rights reserved.
... A avaliação objetiva da efetividade da ventilação pulmonar, realizada por meio do oxímetro de pulso, gasometria ou ETCO2, foi observada em quatro estudos (11,14,17,20) . p=0,56) (12) . O estudo descritivo que avaliou os resultados de 42 pacientes (84%) com ML mostrou valores médios de PO2 de 120 mmHg e PCO2 de 31,1 mmHg (17) . ...
RESUMO
O estudo teve como objetivo analisar a sobrevida, a efetividade da ventilação e a ocorrência de regurgitação associadas ao uso da máscara laríngea em paciente com parada cardiorrespiratória. Trata-se de revisão sistemática realizada nas bases de dados LILACS, Embase, CINAHL, MEDLINE e Cochrane. O total de estudos selecionados foi treze, sendo dois ensaios clínicos, um randomizado controlado e outro não randomizado, e onze estudos descritivos. No ensaio clínico randomizado controlado, a sobrevida dos pacientes que utilizaram a máscara laríngea foi de 7%, mas não houve diferença estatística quando comparada aos outros dispositivos para via aérea. A ventilação pulmonar foi efetiva tanto na avaliação subjetiva quanto na objetiva. A regurgitação foi observada em três casos, mas a frequência não foi estatisticamente diferente dos demais grupos. Os resultados dos estudos desta revisão sistemática indicam a necessidade de realizar estudos controlados e randomizados para analisar os benefícios do uso da máscara laríngea na ressuscitação cardiorrespiratória.
Descritores: Máscaras Laríngeas; Revisão; Parada Cardíaca; Enfermagem em Emergência.
... Another study showed a regurgitation rate of 3.5% with the LMA and 12.4% with bag-mask ventilation 12 . In addition a Japanese study showed similar arterial blood gas values in patients successfully resuscitated after OHCA when either an LMA or bag-mask was used 13 . ...
... The National Protocol for Resuscitation stated that bag-valve-mask ventilation (BVM) was to be used as the first choice for resuscitation, and that an advanced airway device should be considered only when the patient's airway could not be sufficiently secured or a long transportation period was expected (12). ...
Background:
The effect of prehospital use of supraglottic airway devices as an alternative to tracheal intubation on long-term outcomes of patients with out-of-hospital cardiac arrest is unclear.
Study objectives:
We compared the neurological outcomes of patients who underwent supraglottic airway device insertion with those who underwent tracheal intubation.
Methods:
We conducted a nationwide population-based observational study using a national database containing all out-of-hospital cardiac arrest cases in Japan over a 3-year period (2005-2007). The rates of neurologically favorable 1-month survival (primary outcome) and of 1-month survival and return of spontaneous circulation before hospital arrival (secondary outcomes) were examined. Multiple logistic regression analyses were performed to adjust for potential confounders. Advanced airway devices were used in 138,248 of 318,141 patients, including an endotracheal tube (ETT) in 16,054 patients (12%), a laryngeal mask airway (LMA) in 34,125 patients (25%), and an esophageal obturator airway (EOA) in 88,069 patients (63%).
Results:
The overall rate of neurologically favorable 1-month survival was 1.03% (1426/137,880). The rates of neurologically favorable 1-month survival were 1.14% (183/16,028) in the ETT group, 0.98% (333/34,059) in the LMA group, and 1.04% (910/87,793) in the EOA group. Compared with the ETT group, the rates were significantly lower in the LMA group (adjusted odds ratio 0.77, 95% confidence interval [CI] 0.64-0.94) and EOA group (adjusted odds ratio 0.81, 95% CI 0.68-0.96).
Conclusions:
Prehospital use of supraglottic airway devices was associated with slightly, but significantly, poorer neurological outcomes compared with tracheal intubation, but neurological outcomes remained poor overall.
... 86 -91 One pseudorandomized and 1 nonrandomized clinical trial (LOE 2) found no difference in arterial blood gas values or survival rates when a variety of supraglottic airway devices were compared to bag-mask ventilation. 92,93 Three studies performed in manikin models of cardiac arrest (LOE 5) 94 -96 found that, compared with a bag-mask, the use of a single-use, disposable laryngeal tube to provide ventilation may decrease no-flow times. ...
... 333 One study showed similar arterial blood gas values in patients successfully resuscitated after out-of-hospital cardiac arrest when either an LMA or bag mask was used. 373 In comparison with tracheal intubation, the perceived disadvantages of the LMA are the increased risk of aspiration and inability to provide adequate ventilation in patients with low lung and/or chest-wall compliance. There are no data demonstrating whether or not it is possible to provide adequate ventilation via an LMA without interruption of chest compressions. ...
Objective
Blood‐based biomarkers play a central role in the diagnosis and treatment of critically ill patients, yet none are routinely measured during the intra‐arrest phase of out‐of‐hospital cardiac arrest (OHCA). Our objective was to describe methodological aspects, sources of evidence, and gaps in research surrounding intra‐arrest blood‐based biomarkers for OHCA.
Methods
We used scoping review methodology to summarize existing literature. The protocol was designed a priori following the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) Extension for Scoping Reviews. Inclusion criteria were peer‐reviewed scientific studies on OHCA patients with at least one blood draw intra‐arrest. We excluded in‐hospital cardiac arrest and animal studies. There were no language, date, or study design exclusions. We conducted an electronic literature search using PubMed and Embase and hand‐searched secondary literature. Data charting/synthesis were performed in duplicate using standardized data extraction templates.
Results
The search strategy identified 11,834 records, with 118 studies evaluating 105 blood‐based biomarkers included. Only eight studies (7%) had complete reporting. The median number of studies per biomarker was 2 (interquartile range 1–4). Most studies were conducted in Asia (63 studies, 53%). Only 22 studies (19%) had blood samples collected in the prehospital setting, and only six studies (5%) had samples collected by paramedics. Pediatric patients were included in only three studies (3%). Out of eight predefined biomarker categories of use, only two were routinely assessed: prognostic (97/105, 92%) and diagnostic (61/105, 58%).
Conclusions
Despite a large body of literature on intra‐arrest blood‐based biomarkers for OHCA, gaps in methodology and knowledge are widespread.
Airway management is a cornerstone of emergency medical care. This project aimed to create evidence-based guidelines based on the systematic review recently conducted by the Agency for Healthcare Research and Quality (AHRQ). A technical expert panel was assembled to review the evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The panel made specific recommendations on the different PICO (population, intervention, comparison, outcome) questions reviewed in the AHRQ review and created good practice statements that summarize and operationalize these recommendations. The recommendations address the use of ventilation with bag-valve mask ventilation alone vs. supraglottic airways vs. endotracheal intubation for adults and children with cardiac arrest, medical emergencies, and trauma. Additional recommendations address the use of video laryngoscopy and drug-assisted airway management. These recommendations, and the associated good practice statements, offer EMS agencies and clinicians an opportunity to review the available evidence and incorporate it into their airway management strategies.
Objective. To assess comparative benefits and harms across three airway management approaches (bag valve mask [BVM], supraglottic airway [SGA], and endotracheal intubation [ETI]) used by prehospital emergency medical services (EMS) to treat patients with trauma, cardiac arrest, or medical emergencies, and how they differ based on techniques and devices, EMS personnel and patient characteristics.
Data sources. We searched electronic citation databases (Ovid® MEDLINE®, CINAHL®, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus®) from 1990 to September 2020.
Review methods. We followed Agency for Healthcare Research and Quality Effective Health Care Program Methods guidance. Outcomes included mortality, neurological function, return of spontaneous circulation (ROSC), and successful advanced airway insertion. Meta-analyses using profile-likelihood random effects models were conducted, with analyses stratified by study design, emergency type, and age.
Results. We included 99 studies involving 630,397 patients. We found few differences in primary outcomes across airway management approaches.
For survival, there was no difference for BVM versus ETI or SGA in adult and pediatric patients with cardiac arrest or trauma. For neurological function, there was no difference for BVM versus ETI and SGA versus ETI in pediatric patients with cardiac arrest. There was no difference in BVM versus ETI in adults with cardiac arrest, but improved neurological function with BVM or ETI versus SGA. There was no difference in ROSC for patients with cardiac arrest for BVM versus ETI or SGA in adults and pediatrics, or SGA versus ETI in pediatrics. There was higher frequency of ROSC in adults with SGA versus ETI. For successful advanced airway insertion, there was higher first-pass success with SGA versus ETI for all patients except adult medical patients (no difference), and no difference in overall success using SGA versus ETI in adults.
Conclusions. The currently available evidence does not indicate benefits of more invasive airway approaches based on survival, neurological function, ROSC, or successful airway insertion. Strength of evidence was low or moderate; most included studies were observational. This supports the need for high-quality randomized controlled trials to advance clinical practice and EMS education and policy, and improve patient-centered outcomes.
Background
Bag-valve-mask ventilation is the most commonly applied method during cardiopulmonary resuscitation. Globally, advanced airway management with blind insertion devices such as supraglottic airway devices has been implemented for years by different emergency services. The efficiency of ventilation via such devices could be measured by capnography.
Objective
The objective of this study was to determine whether capnography is useful in patients undergoing cardiopulmonary resuscitation and to assess the effectiveness of ventilation via supraglottic airway devices.
Review methods used
This is a systematic review written following the steps of Preferred Reporting Items for Systematic Review and Meta-analyses protocols.
Data sources
A bibliographic search was carried out from the following databases: EBSCOhost, Scopus, EMBASE, Virtual Health Library, PubMed, Cochrane Library, Spanish Medical Index, Spanish Bibliographic Index in Health Sciences, and Latin American and Caribbean Health Sciences Literature, from inception until September 2019.
Review methods
Studies describing the use of capnography with supraglottic airway devices during cardiopulmonary resuscitation manoeuvres were selected and evaluated using the Critical Appraisal Skills Programme.
Results
Twenty-four articles were identified by title and abstract: six were randomised clinical trials, 11 were nonrandomised clinical trials, six were descriptive prospective studies, and one was a descriptive retrospective study. Nine primary research articles were selected for synthesis. Only one provided objective values of capnography obtained with ventilation with these devices, correlating them with the results of resuscitation.
Conclusions
The evidence published so far is scarce, mostly from observational studies with high risk of bias in general. Although a degree of recommendation cannot be established, some results indicate that capnography has the potential to facilitate advanced clinical practice of ventilation with supraglottic airway devices during cardiopulmonary resuscitation.
Introduction
Supraglottic airways, which are easily inserted and minimise interruptions in cardiopulmonary resuscitation manoeuvres, are now widely used in pre- and in-hospital emergencies. However, most studies in these devices do not specify whether they ensure good ventilation during CPR. This systematic review aims to determine whether there is evidence that supraglotic airways enable effective ventilation during resuscitation.
Methods
The MEDLINE and COCHRANE databases were searched for studies published in English up to 30 November 2018. Eligible studies were all those that objectively evaluated tidal volume during resuscitation manoeuvres in patients over 18 years of age using various supraglottic airways.
Results
A total of 3734 articles were identified, of which 252 were duplicates. Only 1 objectively evaluated ventilation during resuscitation manoeuvres and presented data relevant to this review. The study included 470 patients, 51 of which underwent spirometry. Only 4.48% of patients survived to hospital discharge; however, the correlation with ventilation effectiveness was not assessed.
Conclusion
There is no scientific evidence that supraglottic airways provide effective ventilation during resuscitation manoeuvres. Evaluation by spirometry, chest impedance and ultrasound may help to determine the ventilatory efficacy of supraglottic airways during CPR, and clarify whether this factor contributes to the difficulties experienced in reversing cardiorespiratory arrest.
Resumen
Introducción
El uso de dispositivos extraglóticos se ha difundido ampliamente en urgencias pre e intrahospitalarias debido a la facilidad de inserción y la reducción de las interrupciones en las maniobras de reanimación cardiopulmonar. Sin embargo, la mayoría de estos estudios no especifica si dichos dispositivos aseguran una ventilación adecuada durante la reanimación cardiopulmonar. Esta revisión sistemática tiene como objetivo principal determinar si existe evidencia que demuestre que los dispositivos extraglóticos permiten una ventilación efectiva durante la reanimación.
Métodos
Se han utilizado las bases de datos de MEDLINE y COCHRANE para buscar estudios elegibles publicados en inglés hasta el 30 de noviembre de 2018. Los estudios considerados elegibles fueron todos aquellos que han evaluado objetivamente el volumen tidal durante las maniobras de reanimación, en diversos dispositivos extraglóticos y en pacientes mayores de 18 años.
Resultados
Se identificaron 3.734 artículos, de los cuales 252 eran duplicados. Solo uno evaluó objetivamente la ventilación durante las maniobras de reanimación y presentó datos relevantes para esta revisión. En este ensayo de 470 pacientes, se realizó una espirometría en 51 pacientes. Solo el 4,48% de los pacientes sobrevivieron hasta el alta hospitalaria, sin embargo, no se evaluó la relación con la efectividad de la ventilación.
Conclusión
No existe evidencia científica que demuestre que los dispositivos extraglóticos proporcionan una ventilación efectiva durante las maniobras de reanimación. La evaluación mediante espirometría, impedancia torácica y ultrasonido podría ayudar a discernir la eficacia ventilatoria de los dispositivos extraglóticos durante la reanimación cardiopulmonar y aclarar si este factor está contribuyendo de manera negativa en las dificultades experimentadas para revertir el paro cardiorrespiratorio en los pacientes.
Aim:
To systematically review the literature on advanced airway management during adult cardiac arrest in order to inform the International Liaison Committee of Resuscitation (ILCOR) consensus on science and treatment recommendations.
Methods:
The review was performed according to PRISMA guidelines and registered on PROSPERO (CRD42018115556). We searched Medline, Embase, and Evidence-Based Medicine Reviews for controlled trials and observational studies published before October 30, 2018. The population included adult patients with cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed the risk of bias of individual studies.
Results:
We included 78 observational studies and 11 controlled trials. Most of the observational studies and all of the controlled trials only included patients with out-of-hospital cardiac arrest. The risk of bias for individual observational studies was overall assessed as critical or serious, with confounding and selection bias being the primary sources of bias. Three of the controlled trials, all published in 2018, were powered for clinical outcomes with two comparing a supraglottic airway to tracheal intubation and one comparing bag-mask ventilation to tracheal intubation. All three trials had some concerns regarding risk of bias primarily due to lack of blinding and variable adherence to the protocol. Clinical and methodological heterogeneity across studies, for both the observational studies and the controlled trials, precluded any meaningful meta-analyses.
Conclusions:
We identified a large number of studies related to advanced airway management in adult cardiac arrest. Three recently published, large randomized trials in out-of-hospital cardiac arrest will help to inform future guidelines. Trials of advanced airway management during in-hospital cardiac arrest are lacking.
Background:
Anti-arrhythmic drugs (AAD) are often used for fatal ventricular arrhythmias during cardio-pulmonary resuscitation (CPR). However, the efficacy of initial AAD administration during CPR in improving long-term prognosis remains unknown. This study retrospectively evaluated the effect of AAD administration during CPR on 1-month prognosis in the SOS-KANTO 2012 study population.
Methods and results:
Of the 16,164 out-of-hospital cardiac arrest cases, 1,350 shock-refractory patients were included: 747 patients not administered AAD and 603 patients administered AAD. Statistical adjustment for potential selection bias was performed using propensity score matching, yielding 1,162 patients of whom 792 patients were matched (396 pairs). The primary outcome was 1-month survival. The secondary outcome was the proportion of patients with favorable neurological outcome at 1 month. Logistic regression with propensity scoring demonstrated an odds ratio (OR) for 1-month survival in the AAD group of 1.92 (P < 0.01), whereas the OR for favorable neurological outcome at 1 month was 1.44 (P = 0.26).
Conclusion:
Significantly greater 1-month survival was observed in the AAD group compared with the non-AAD group. However, the effect of anti-arrhythmic drugs on the likelihood of a favorable neurological outcome remains unclear. The findings of the present study may indicate a requirement for future randomized controlled trials evaluating the effect of anti-arrhythmic drug administration during CPR on long-term prognosis.
The primary components of standard cardiopulmonary resuscitation (CPR) are chest compressions to circulate blood) defibrillation to convert a ‘shockable’ rhythm into one that will produce a spontaneous circulation) and ventilation of the lungs to enable oxygenation of the blood and removal of carbon dioxide (CO2). Effective ventilation of the lungs requires a patent airway) while protection of the lungs from aspiration of gastric contents requires reliable separation of the gastrointestinal tract from the airway. Traditionally) the single airway device deemed capable of maintaining airway patency and protecting from aspiration is the tracheal tube. However) the unique status of tracheal intubation is now being challenged. Tracheal intubation is associated with several complications and it is possible that it would be better for healthcare professionals who are not highly skilled in this intervention to use alternative airway devices. After primary cardiac arrest) based mainly on animal data) but also on some low-level human data) ventilation may not be necessary for several minutes. Recent observational clinical studies suggest that chest compression-only CPR by bystanders results in the same or better outcomes than bystander CPR that includes both mouth-to-mouth breathing and chest compressions. There are data indicating that excessive ventilation is harmful during CPR and) possibly) after return of spontaneous circulation. This chapter will focus on the evidence supporting new strategies for management of the airway and ventilation during CPR.
Amiodarone (AMD), nifekalant (NIF), and lidocaine (LID) hydrochlorides are widely used for ventricular tachycardia/fibrillation (VT/VF). This study retrospectively investigated the NIF potency and the differential effects of two initial AMD doses (≤ 150 mg or 300 mg) in the Japanese SOS-KANTO 2012 study population.
From 16 164 out-of-hospital cardiac arrest cases, 500 adult patients using a single antiarrhythmic drug for shock-resistant VT/VF were enrolled and categorized into four groups (73 LID, 47 NIF, 173 AMD-≤ 150, and 207 AMD-300). Multivariate analyses evaluated the outcomes of NIF, AMD-≤ 150, or AMD-300 groups versus LID group. Odds ratios (ORs) for survival to admission were 3.21 (95% confidence interval [CI]: 1.38-7.44, p < 0.01) in NIF and 3.09 (95% CI: 1.55-6.16, p < 0.01) in AMD-≤ 150 groups, and significantly higher than those of the LID group. However, the OR was 1.78 (95% CI: 0.90-3.51, p = 0.10) in AMD-300 group, and was not significant than LID group. ORs for 24-h survival were 6.68 in NIF, 4.86 in AMD-≤ 150, and 2.97 in AMD-300, being significantly higher in these groups.
NIF and AMD result in similar improvements for 24-hour survival in cardiopulmonary arrest patients, and this suggest the necessity of a randomized control study.
AimThe current study compares pre- and in-hospital management and outcomes of out-of-hospital cardiac arrest cases between 2002 and 2012 in the Kanto region of Japan.Methods
We compared the data collected for the SOS-KANTO study project in 2002 and 2012. We included adult patients (aged >18 years) who experienced bystander-witnessed out-of-hospital cardiac arrest of cardiac etiology. The outcomes were as follows: proportion of favorable neurological outcomes at 1 month, bystander cardiopulmonary resuscitation provision, and pre- and postresuscitation treatment administration.ResultsOf 4,171 patients (1,982 in SOS-KANTO in 2002 and 2,189 in 2012), the proportion of those with favorable neurological outcomes at 1 month (4.8% versus 9.0%, P < 0.001), and bystander cardiopulmonary resuscitation rates increased significantly between 2002 and 2012 (24.5% versus 38.9%, P < 0.001). Although none were documented in 2002, 118 cases (5.4%) of layperson use of an automated external defibrillator were recorded in 2012. Relative to 2002, use of an i.v. line to provide fluid was more frequently attempted and carried out successfully by emergency medical service providers in 2012. Among cases in which return of spontaneous circulation was achieved, more postresuscitation treatment was provided in 2012 (13.3% versus 43.8%, P < 0.001) relative to that provided in 2002.Conclusions
Proportions of bystander cardiopulmonary resuscitation, layperson use of automated external defibrillator, provision of prehospital adrenaline and postresuscitation treatment, and favorable neurological outcomes at 1 month increased significantly over 10 years in the Kanto region of Japan.
Background:
The 2010 CPR Guidelines recommend that extracorporeal cardiopulmonary resuscitation (ECPR) using an emergency cardiopulmonary bypass (CPB) should be considered for patients with cardiac arrest. However, it is not yet clear whether this therapy can improve cerebral circulation and oxygenation in these patients. To clarify this issue, we evaluated changes of cerebral blood oxygenation (CBO) during ECPR using near-infrared spectroscopy (NIRS).
Methods:
We employed NIRS to measure CBO in the bilateral frontal lobe in patients transported to the emergency room (ER) after out-of-hospital cardiac arrest between November 2009 and June 2011.
Results:
Fifteen patients met the above criteria. The tissue oxygenation index (TOI) on arrival at the ER was 36.5 %. This increased to 67.8 % during ECPR (P < 0.001). The one patient whose TOI subsequently decreased had a favorable neurological outcome.
Conclusion:
Increase of TOI during ECPR might reflect an improvement in cerebral blood flow, while decrease of TOI after ECPR might reflect oxygen utilization by the brain tissue as a result of neuronal cell survival. NIRS may be useful for monitoring cerebral hemodynamics and oxygen metabolism during CPR.
h2>Introduction
Prehospital care providers are responsible for providing adequate ventilation during cardiopulmonary resuscitation (CPR). Endotracheal intubation (ETI) is widely accepted as the 'gold standard' for airway protection and the preferred method for ventilation. However, most Australian paramedics are not trained to perform ETI. Laryngeal Mask Airway (LMA) and Bag-Valve-Mask (BVM) are seen as adequate alternatives to ETI as recommended by the International Liaison Committee of Resuscitation (ILCOR). The objective of this study was to identify which airway device LMA or BVM (with OPA/NPA) is more effective in airway patency and ventilation during cardiopulmonary resuscitation in the prehospital environment.
Methods
A literature search was conducted using medical electronic databases, MEDLINE CINHAL, EMBASE, Meditext, Cochrane Central Register of Controlled Trials (CENTRAL), and Scopus. These databases were searched from January 1996 until the end of January 2010. Articles were included if the principal objective was to compare ventilation efficiency of the LMA against the BVM in the prehospital setting. References from articles retrieved were reviewed.
Results
There were 2937 articles located by the search. Of these, 30 articles met the inclusion criteria with twelve relevant to the prehospital environment. In the twelve prehospital studies, two involved the use of mannequins, four were retrospective, five were observational, and there was one a literature review.
Conclusion
The findings from this review suggest that the LMA is more effective at ventilations over time during CPR in adults, as there is less risk of gastric regurgitation and pulmonary aspiration. The BVM is quicker at performing the first ventilation but there is a loss of effectiveness over time. BVM is considered the best method for ventilating children and neonates.</p
It is unclear whether advanced airway management during ambulance transport is associated with improved out-of-hospital cardiac arrest (OHCA) outcomes compared with bag-valve mask ventilation (BVM). This study aimed to determine whether EMT-intermediate ETI or LMA is associated with improved OHCA outcomes in Korea.
We used a Korean national OHCA cohort database composed of hospital and ambulance data. We included all EMS-treated by level 1 EMTs (EMT-intermediate level) and OHCA with presumed cardiac etiology for the period January 2006-December 2008. We excluded cases not receiving continued resuscitation in the emergency department (ED), treated by level 2 EMT, as well as those without available hospital outcome data. The primary exposure was airway management technique during ambulance transport (endotracheal tube (ETI), laryngeal mask airway (LMA) or bag-valve-mask ventilation with an oropharyngeal airway). The primary outcomes were survival to admission and survival to hospital discharge. We compared outcomes between each airway management group using multivariable logistic regression, adjusting for sex, age, witnessed, prehospital defibrillation, bystander cardiopulmonary resuscitation (CPR), call to ambulance arrival time to the scene, call to ambulance arrival time to ED, initial ECG, metropolitan (defined as population>1 million), and level of ED (higher versus lower level). We repeated the analysis using propensity-score matched subsets.
Of 54,496 patients with OHCA, we included 5278 (9.7%). Overall survival to admission and to discharge was 20.2% and 6.9%, respectively. ETI and LMA were performed in 250 (4.7%) and 391 (7.4%), respectively. In the full multivariable models using total patients, adjusted survival to admission and discharge were similar for ETI and BVM: OR 0.91 (0.66-1.27) and 1.00 (0.60-1.66), respectively. Adjusted survival to admission and discharge were significantly lower in LMA than BVM: OR 0.72 (0.54-0.95) and 0.52 (0.32-0.85), respectively. In the full multivariable models using propensity matched samples, adjusted survival to admission and discharge were similar for ETI and BVM; OR 1.32 (0.81-2.16) and 1.44 (0.66-3.15), respectively. Adjusted survival to admission was similar for LMA and BVM: OR 0.72 (0.50-1.02). However, survival to discharge was significantly lower for LMA than BVM: OR 0.45 (0.25-0.82).
In Korea, EMT-I placed LMA during ambulance transport was associated with worsened OHCA survival to discharge than BVM. Outcomes were similar between EMT-I endotracheal intubation and bag-valve-mask ventilation.
Note From the Writing Group: Throughout this article, the reader will notice combinations of superscripted letters and numbers (eg, “Family Presence During ResuscitationPeds-003”). These callouts are hyperlinked to evidence-based worksheets, which were used in the development of this article. An appendix of worksheets, applicable to this article, is located at the end of the text. The worksheets are available in PDF format and are open access.
The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.
The critical lifesaving steps of BLS are ● Immediate Recognition and Activation of the emergency response system ● Early CPR and ● Rapid Defibrillation for VF. When an adult suddenly collapses, whoever is nearby should activate the emergency system and begin chest compressions (regardless of training). Trained lay rescuers who are able and healthcare providers should provide compressions and ventilations. Contrary to the belief of too many in this situation, CPR is not harmful. Inaction is harmful and CPR can be lifesaving. However, the quality of CPR is critical. Chest compressions should be delivered by pushing hard and fast in the center of the chest (ie, chest compressions should be of adequate rate and depth). Rescuers should allow complete chest recoil after each compression and minimize interruptions in chest compressions. They should also avoid excessive ventilation. If and when available, an AED should be applied and used without delaying chest compressions. With prompt and effective provision of these actions, lives are saved every day.
Note From the Writing Group: Throughout this article, the reader will notice combinations of superscripted letters and numbers (eg, “Family Presence During ResuscitationPeds-003”). These callouts are hyperlinked to evidence-based worksheets, which were used in the development of this article. An appendix of worksheets, applicable to this article, is located at the end of the text. The worksheets are available in PDF format and are open access.
The 2010 ILCOR Pediatric Task Force experts developed 55 questions related to pediatric resuscitation. Topics were selected based on the 2005 Consensus on Science and Treatment Recommendations (CoSTR) document,1,2 emerging science, and newly identified issues. Not every topic reviewed for the 2005 International Consensus on Science was reviewed in the 2010 evidence evaluation process. In general, evidence-based worksheets were assigned to at least 2 authors for each topic. The literature search strategy was first reviewed by a “worksheet expert” for completeness. The expert also approved the final worksheet to ensure that the levels of evidence were correctly assigned according to the established criteria. Worksheet authors were requested to draft CoSTR statements (see Part 3: Evidence Evaluation Process). Each worksheet author or pair of authors presented their topic to the Task Force in person or via a webinar conference, and Task Force members discussed the available science and revised the CoSTR draft accordingly. These draft CoSTR summaries were recirculated to the International Liaison Committee on Resuscitation (ILCOR) Pediatric Task Force for further refinement until consensus was reached. Selected controversial and critical topics were presented at the 2010 ILCOR International Evidence Evaluation conference in Dallas, Texas, for further discussion to obtain additional input and feedback. This document presents the 2010 international consensus on the science, treatment, and knowledge gaps for each pediatric question.
The most important changes or points of emphasis …
Note From the Writing Group: Throughout this article, the reader will notice combinations of superscripted letters and numbers (eg, “Cricoid Pressure ALS-CPR&A-007B ”). These callouts are hyperlinked to evidence-based worksheets, which were used in the development of this article. An appendix of worksheets, applicable to this article, is located at the end of the text. The worksheets are available in PDF format and are open access. The topics reviewed by the International Liaison Committee on Resuscitation (ILCOR) Advanced Life Support Task Force are grouped as follows: (1) airway and ventilation, (2) supporting the circulation during cardiac arrest, (3) periarrest arrhythmias, (4) cardiac arrest in special circumstances, (5) identifying reversible causes, (6) postresuscitation care, (7) prognostication, and (8) organ donation. Defibrillation topics are discussed in Part 6.
The most important developments and recommendations in advanced life support (ALS) since the 2005 ILCOR review are as follows:
The use of the Esophageal Obturator Airway (EOA) was prospectively studied in 300 cases ofprehospital cardiac arrests. Seventy-seven complications were documented in 72 patients. Inadvertent tracheal intubation occurred in 13 patients, five unrecognized. No differences were found when initial emergency room rhythm and resuscitation outcome were compared to aprevious study using the oral airway (OA). A subgroup of 124 EOA and 55 OA patients were compared. The EOA was effective in reducing the frequency of aspiration (17 vs 34 per cent). Arterial oxygenation was similar, and rose in both groups following tracheal intubation. Esophageal traumawas found in 10 per cent of the EOA patients who underwent autopsy. Although the EOA is useful in prehospital emergency care, the only advantage for this technique in comparison to the OA is the prevention of aspiration of gastric contents. It also appears that other techniques of advanced cardiac life support, i.e. defibrillation, drug therapy, etc. are necessary to improve survival statistics.
To compare two airway management techniques, face mask (FM) with oropharyngeal airway and laryngeal mask airway (LMA), with respect to the effectiveness of positive pressure ventilation and airway maintenance.
After induction of anaesthesia, two airway management techniques (FM or LMA) and three peak pressures (20, 25 and 30 cm H2O) were randomly applied during controlled ventilation in 60 patients. Data collected included inspiratory and expiratory volumes and presence of gastro-oesophageal insufflation. Leak was calculated by subtracting the expiratory from the inspiratory volume, expressed as a fraction of the inspiratory volume.
Expiratory volumes (mean +/- SD) at 20, 25 and 30 cm H2O for LMA ventilation were 893 +/- 260, 986 +/- 276 and 1006 +/- 262 respectively, and for FM ventilation 964 +/- 264, 1100 +/- 268 and 1116 +/- 261. Leak fractions at 20, 25 and 30 cm H2O for LMA ventilation were 0.21 +/- 0.15, 0.24 +/- 0.18 and 0.26 +/- 0.18 respectively, and for FM ventilation 0.14 +/- 0.09, 0.14 +/- 0.09 and 0.12 +/- 0.08. The frequency of gastro-oesophageal insufflation was 1.6%, 5% and 5% for the LMA and 5%, 15% and 26.6% for the FM for ventilation pressures of 20, 25 and 30 cm H2O respectively which was greater with LMA use.
Ventilation was adequate in all patients using both techniques. Leak was pressure dependent and greater with LMA use. Most of the leak was vented to the atmosphere via the pharynx. Gastro-oesophageal insufflation was more frequent with ventilation using the face mask. LMA use with positive pressure ventilation would appear to be a better airway management method than the face mask.
We have studied the incidence of gastro-oesophageal reflux associated with the laryngeal mask airway (LMA) in 82 paralysed
patients undergoing ventilation for elective orthopaedic surgery. Anaesthesia was managed by skilled LMA users. A pH-sensitive
probe was passed nasally into the oesophagus before induction and recordings made during five phases of anaesthesia. Anaesthesia
was induced with propofol and fentanyl and maintained with 0.5-1.5% isoflurane and nitrous oxide in oxygen. Neuromuscular
block was produced with vecuronium and the train-of-four count maintained at < or = 1. Towards the end of surgery, neuromuscular
function was allowed to recover spontaneously. All LMAs were inserted at the first attempt and ventilation was successful
in all patients. There were no adverse airway events. Mean oesophageal pH values during each phase of anaesthesia were: before
insertion 5.88 (SD 0.77), placement 5.85 (0.74), maintenance 5.89 (0.73), emergence 5.71 (0.78) and removal 5.82 (0.75). There
were no reflux events (pH < 4.0) during any phase of anaesthesia. We conclude that the incidence of gastro-oesophageal reflux
is low in paralysed patients undergoing ventilation for elective orthopaedic surgery when antagonism of neuromuscular block
is avoided. The validity of these findings for unskilled LMA users is unknown.
Out-of-hospital cardiac arrest is a major public health problem.
To investigate whether the survival of patients with out-of-hospital cardiac arrest would improve with minimally interrupted cardiac resuscitation (MICR), an alternate emergency medical services (EMS) protocol.
A prospective study of survival-to-hospital discharge between January 1, 2005, and November 22, 2007. Patients with out-of-hospital cardiac arrests in 2 metropolitan cities in Arizona before and after MICR training of fire department emergency medical personnel were assessed. In a second analysis of protocol compliance, patients from the 2 metropolitan cities and 60 additional fire departments in Arizona who actually received MICR were compared with patients who did not receive MICR but received standard advanced life support.
Instruction for EMS personnel in MICR, an approach that includes an initial series of 200 uninterrupted chest compressions, rhythm analysis with a single shock, 200 immediate postshock chest compressions before pulse check or rhythm reanalysis, early administration of epinephrine, and delayed endotracheal intubation.
Survival-to-hospital discharge.
Among the 886 patients in the 2 metropolitan cities, survival-to-hospital discharge increased from 1.8% (4/218) before MICR training to 5.4% (36/668) after MICR training (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.9). In the subgroup of 174 patients with witnessed cardiac arrest and ventricular fibrillation, survival increased from 4.7% (2/43) before MICR training to 17.6% (23/131) after MICR training (OR, 8.6; 95% CI, 1.8-42.0). In the analysis of MICR protocol compliance involving 2460 patients with cardiac arrest, survival was significantly better among patients who received MICR than those who did not (9.1% [60/661] vs 3.8% [69/1799]; OR, 2.7; 95% CI, 1.9-4.1), as well as patients with witnessed ventricular fibrillation (28.4% [40/141] vs 11.9% [46/387]; OR, 3.4; 95% CI, 2.0-5.8).
Survival-to-hospital discharge of patients with out-of-hospital cardiac arrest increased after implementation of MICR as an alternate EMS protocol. These results need to be confirmed in a randomized trial.
After a short training programme 11 naval medical trainees inserted a laryngeal mask airway (LMA) and a tracheal tube (ETT) in random order in a total of 110 anaesthetized patients. They were allowed 40 seconds for each attempt. Success was defined as the detection of expired carbon dioxide within 40 seconds of Guedel airway removal which subsequently rose to an end-tidal value of at least 4 kPa, together with satisfactory lung expansion and ventilation, without other airway intervention by the anaesthetist. One hundred and four LMA insertions were successful compared with 56 ETTs (p<0.01). All first attempts at LMA insertion were successful, whereas satisfactory ETT placement was progressive. Insertion was also quicker with the LMA (20 seconds) than with the ETT (35 seconds) (p<0.01). Further studies are indicated to assess the value of the LMA in emergencies.
The laryngeal mask airway (LMA) has become a popular tool for airway management in selected adult and pediatric patients undergoing routine surgical procedures.The relationship between end-tidal and arterial carbon dioxide during controlled ventilation via the LMA in infants under 10 kg has not been reported. After induction of general anesthesia, the LMA was placed in 12 healthy infants and mechanical ventilation initiated. After maintaining steady-state level of end-tidal carbon dioxide (minimum 5 min), an arterial blood sample was obtained and end-tidal carbon dioxide level noted. The laryngeal mask was then removed, the trachea intubated, and mechanical ventilation resumed with initial ventilatory variables. After reaching a steady-state level of end-tidal carbon dioxide, a second arterial sample was obtained and end-tidal carbon dioxide level noted. The mean end-tidal carbon dioxide and arterial partial pressure of carbon dioxide obtained during ventilation were 42.2 +/- 7.9 and 47.1 +/- 11.0 (LMA) and 37.4 +/- 4.6 and 42.6 +/- 6.7 (endotracheal tube), respectively. Analysis of differences between partial pressure of carbon dioxide and end-tidal carbon dioxide using the Bland and Altman method revealed bias +/- precision of 4.9 +/- 3.9 and 5.3 +/- 3.2 with ventilation via the laryngeal mask and endotracheal tube. Our data indicate that, while ventilating infants under 10 kg with LMA, end-tidal carbon dioxide is an accurate indicator of arterial partial pressure of carbon dioxide.
(Anesth Analg 1997;84:51-3)
Background Although there is a close connection between emergency medical services (EMS) system and the outcome of out-of-hospital ventricular fibrillation (VF), few data are available regarding the situation in Japan. Methods and Results A prospective multicenter study of out-of-hospital cardiac arrest was conducted according to the Utstein guidelines. A total of 4,383 patients who were given cardiopulmonary resuscitation (CPR) by EMS personnel for out-of-hospital cardiac arrest were enrolled. The proportion of VF or pulseless ventricular tachycardia (VT) as the first cardiac rhythm after cardiac arrest was 16.2% with a mean call-to-initial-recorded-electrocardiogram (ECG) interval of 11.1 min. In a subgroup of patients with witnessed collapse, the predicted incidence of VF or pulseless VT was 62.7% at the time of cardiac arrest, and the decline accelerated with every minute that the collapse-to-initial ECG interval was delayed. Multivariate analysis showed that the odds ratio for VF or pulseless VT after collapse-to-initial ECG interval was 0.91 (95% confidence interval (CI), 0.89-0.94, p<0.001), and 1.54 (95%CI, 1.24-1.97, p<0.001) after bystander CPR. Conclusions In Japan, VF occurred in 63% of cases at the time of cardiac arrest and the performance of bystander CPR appeared to prolong VF. (Circ J 2005; 69: 1157 - 1162)
A multicentre study was undertaken to assess the potential value of the laryngeal mask airway when inserted by ward nurses during resuscitation as a method of airway management prior to the arrival of the Advanced Life Support Team with tracheal intubation capability. The nurses underwent a training programme agreed by all the participating hospitals and followed an identical protocol and data recording system. One hundred and thirty nurses were trained and 164 cases of cardiac arrest were studied. The laryngeal mask airway was inserted at the first attempt in 71% and at the second attempt in 26% of cases. Satisfactory chest expansion occurred in 86% of cases. The mean interval between cardiac arrest and laryngeal mask airway insertion was 2.4 min. Regurgitation of gastric contents occurred before airway insertion in 20 cases (12%), during the insertion in three cases (2%) but there was clinical evidence of pulmonary aspiration in only one patient who survived to leave hospital. We conclude that the laryngeal mask airway offers advantages over other methods of airway and ventilation management such as the bag-valve-mask or mouth-to-mouth methods that are currently used by ward nurses in resuscitating patients with cardiac arrest. In this study the laryngeal mask airway was not being compared with the tracheal tube.
An evaluation of the laryngeal mask airway (LMA) as a means of airway support when used by paramedical personnel was performed. Forty medical and paramedical students attempted to intubate the tracheas of 40 healthy anesthetized adults with the LMA and a cuffed endotracheal tube (ETT). The number of attempts to achieve correct placement and the time taken to adequately ventilate the lungs were recorded for both devices. End-tidal carbon dioxide was detected significantly sooner after commencement of the intubation attempt using the LMA (mean 38.6 s) compared with the ETT (mean 88.3 s, P less than 0.0001). Ninety-four percent of the students successfully ventilated the lungs on their first attempt with the LMA, whereas only 69% intubated the trachea on their first attempt with the ETT (P less than 0.01). Five students were unable to intubate the trachea after three attempts with the ETT, but all positioned the LMA satisfactorily on their first try in a mean time of 40 s. We conclude that unskilled operators with minimal training can safely and successfully ventilate unconscious patients more rapidly using the LMA than the ETT. These results suggest the LMA should be available in all areas where resuscitation is performed.
After a short training programme 11 naval medical trainees inserted a laryngeal mask airway (LMA) and a tracheal tube (ETT) in random order in a total of 110 anaesthetised patients. They were allowed 40 s for each attempt. Success was defined as the detection of expired carbon dioxide within 40 s of Guedel airway removal which subsequently rose to an end-tidal value of at least 4 kPa, together with satisfactory lung expansion and ventilation, without other airway intervention by the anaesthetist. 104 LMA insertions were successful compared with 56 of ETTs (p less than 0.01). All first attempts at LMA insertion were successful, whereas satisfactory ETT placement was progressive. Insertion was also quicker with the LMA (20 s) than with the ETT (35 s) (p less than 0.01). Further studies are indicated to assess the value of the LMA in emergencies.
The success of cardiopulmonary resuscitation after cardiac arrest depends not only on the duration of the arrest, but also on the prompt establishment of a patent airway. In this study, we tested the safety and promptness of intubation with esophageal tracheal combitube (ETC) when compared to conventional endotracheal airway. Effectiveness of ventilation via the ETC as shown by blood gas analyses appeared to be comparable to endotracheal airway. Data suggest that the ETC might serve as a useful device during cardiopulmonary resuscitation.
Prompt establishment of an airway is a primary goal in CPR of nonbreathing and unconscious patients. The esophageal tracheal combitube (ETC) is a new airway, designed for emergency intubation providing sufficient ventilation whether the airway is placed into the trachea or into the esophagus. We evaluated the effectiveness of the ETC in 31 patients during CPR. Blood gas analyses obtained during esophageal placement of the ETC showed results comparable to those of ventilation with a conventional endotracheal airway (ETA). The ETC appeared to oxygenate and ventilate patients adequately without complications. The efficacy, safety, and ease of insertion ensure rapid airway control. It is concluded that the ETC provides a sufficient alternative to the ETA whenever ideal conditions or trained staff for endotracheal intubation are not immediately available.
The use of the Esophageal Obturator Airway (EOA) was prospectively studied in 300 cases of prehospital cardiac arrests. Seventy-seven complications were documented in 72 patients. Inadvertent tracheal intubation occurred in 72 patients. Inadvertent tracheal intubation occurred in 13 patients, five unrecognized. No differences were found when initial emergency room rhythm and resuscitation outcome were compared to a previous study using the oral airway (OA). A subgroup of 124 EOA and 55 OA patients were compared. The EOA was effective in reducing the frequency of aspiration (17 vs 34 per cent). Arterial oxygenation was similar, and rose in both groups following tracheal intubation. Esophageal trauma was found in 10 per cent of the EOA patients who underwent autopsy. Although the EOA is useful in prehospital emergency care, the only advantage for this technique in comparison to the OA is the prevention of aspiration of gastric contents. It also appears that other techniques of advanced cardiac life support, i.e. defibrillation, drug therapy, etc. are necessary to improve survival statistics.
The laryngeal mask airway (LMA) has been newly introduced to anaesthesia practice as an alternative to the endotracheal tube (ETT) or face mask for airway management. It is capable of providing a rapid and easily achieved patent airway that permits positive pressure ventilation within confined limits. In this study, we aim to evaluate the role of the LMA in cardiopulmonary resuscitation (CPR) in 20 patients as an alternative to tracheal intubation. Study parameters included measurement of oxygen saturation by a pulse oximeter and end-tidal carbon dioxide level (ETCO2) using the Fenem CO2 analyser. Five of these 20 cases were resuscitated using endotracheal tubes as a control group. Seven cases were resuscitated using LMA only and eight cases were resuscitated using LMA initially followed by ETT for long term ventilation. In the LMA groups I and III, 12 patients had LMA inserted at the first attempt and three at a second attempt. We concluded that LMA is a good alternative to ETT, although it may not protect against aspiration. We recommend it to be included in CPR chart cards and all medical doctors, nurses and paramedical staff should learn how to use it.
To determine the learning curve of nonphysician emergency personnel on placement of the laryngeal mask airway as compared to performance of endotracheal intubation.
Prospective, comparative, randomized, patient-blinded trial.
Regional hospital operating room.
Seven experienced paramedics and 12 respiratory therapists trained in endotracheal intubation.
Patients used as subjects were anesthetized and paralyzed. Each participant then performed placement of both the laryngeal mask airway and endotracheal tube on the same patient in random sequence. Both techniques were observed for speed, difficulty, and effectiveness.
The techniques were timed from the point at which the participant touched the patient to the time they were able to effectively ventilate the patient. Participants also were asked to rate the difficulty of each technique on a 100-mm visual analog score. Failure (three attempts without successful ventilation) rates also were monitored. The mean time to ventilate successfully with the laryngeal mask airway was significantly less than that with the endotracheal tube (38.9 +/- 1.9 seconds versus 206.1 +/- 31.9 seconds, P < .0001). The average number of attempts was 1.0 +/- 0.0 for the laryngeal mask airway and 2.22 +/- 0.21 for the endotracheal tube (P < .01). No one failed to place the laryngeal mask airway; and ten of 19 (52.6%, P < .01) failed to perform endotracheal intubation. The endotracheal tube had a significantly higher rating of difficulty than did the laryngeal mask airway (67.3 versus 8.64, P < .0001).
A prospective controlled study was undertaken to evaluate the efficacy of the Combitube, a combined endotracheal and esophageal obturator airway adjunct, in prehospital cardiac arrest patients. The Combitube and a standard endotracheal tube were utilized on alternate days as the initial airway of choice by paramedics. Of altogether 86 patients treated during the study period, intubation was possible in 80 cases, 38 receiving a Combitube as initial choice of airway. 11 out of 14 patients who could not be intubated with a standard endotracheal tube were then successfully managed with a Combitube. Survival following cardiac arrest after insertion of a Combitube was comparable to conventional endotracheal intubation. Of the 6 patients who survived 2 had received a Combitube, 2 a standard endotracheal tube and 2 an oropharyngeal tube. While visualized endotracheal intubation remains the preferred method of airway control, the Combitube is an effective airway as backup to the endotracheal tube, as well as a primary airway, especially outside hospital. Contraindications are listed.
The laryngeal mask airway (LMA) was used within the hospital in 50 cardiac arrest cases during cardio-pulmonary resuscitation (CPR). The LMA was inserted mainly by junior anaesthesia staff members with no previous experience with its use. The LMA was easily inserted providing a clear and unobstructed airway in 98% of the patients with clinically satisfactory ventilation and very good blood gas values. No signs of regurgitation or aspiration were detected.
To evaluate the ability of paramedics in a nonurban emergency medical services system to use the Combitube, a combined endotracheal and esophageal obturator airway adjunct, in prehospital cardiac arrest patients.
A prospective, controlled study to evaluate the difficulty and complications of insertion, recognition of esophageal versus tracheal placement, skill proficiency, and retention. The ability to use the device in cases of failed endotracheal intubation also was scrutinized.
Evaluation of the paramedic's ability to use the Combitube was performed in a prehospital environment. A follow-up study to determine retention of insertion skill was conducted in a controlled laboratory setting.
Fifty-two cases of paramedic prehospital Combitube insertion were examined, and 11 paramedics were evaluated for skill retention.
Combitube insertion was attempted on 52 prehospital patients in cardiac arrest, and 69% were intubated successfully. Paramedics recognized esophageal versus tracheal placement in 100% of the cases. The Combitube was inserted successfully into 64% of the patients who could not be endotracheally intubated by the conventional visualized method. The Combitube was inserted successfully 71% of the time when used as a first-line airway adjunct. A follow-up study on 11 randomly selected paramedics involved in the field study was conducted 15 months later. Nine of 11 paramedics demonstrated inadequate skill retention in the follow-up study.
Although visualized endotracheal intubation remains the preferred method of airway control, the Combitube may be an effective prehospital airway device as both a backup to the endotracheal tube and a primary airway. Although the Combitube does not require visualization with a laryngoscope, comprehensive training and continuing education are key factors affecting skill retention.
For a period of 13 months adult patients sustaining a cardiopulmonary arrest in the Royal East Sussex Hospital, Hastings, were attended by nursing staff and Operating Department Assistants (ODAs) specially trained in the use of the laryngeal mask (LM) as an airway adjunct. The LM was used 41 times in 40 patients. The LM failed on only two occasions, and was successful in three cases where endotracheal intubation proved impossible. No instances of aspiration were directly attributable to LM use. LM trained staff adopted its use enthusiastically, and skills acquired during training appeared not to fade over the period of the study. These results are considered to justify the performance of a large-scale trial of use of the LM in cardiac arrest patients.
Although endotracheal intubation is still the most definitive technique for airway management in patients with cardiac or respiratory arrest, in some emergency care systems, use of endotracheal intubation by prehospital care personnel has been restricted by policy or statute. Therefore, alternative airway devices have been developed. These alternative airway devices include the Esophageal Obturator Airway (EOA) and Esophageal Gastric Tube Airway (EGTA), the Pharyngeotracheal Lumen Airway (PTL), and the Esophageal-Tracheal Combitube (ETC). By examining the available literature concerning these alternative airway devices, we sought to determine 1) if these devices are superior to basic, noninvasive airway techniques (eg, bag-valve-mask ventilation); 2) if they are comparable to endotracheal intubation in terms of ventilation, oxygenation, and potential complications; 3) what the role of these devices should be in prehospital care; and 4) what the best recommendations should be regarding these devices in terms of resuscitation training and future areas for research. The review involved a total of 837 EOA/EGTA, 304 PTL, and 159 ETC study patients. Although ventilation and oxygenation can, in some circumstances, be as good with the EOA/EGTA devices as it is with the endotracheal intubation, in some cases they can be inadequate, and the complication rate is relatively high. Preliminarily, the PTL and the ETC seem to provide adequate ventilation and oxygenation with few complications. However, for both devices, published clinical experience, especially in the prehospital setting, is still limited. Therefore, their use should be left to the discretion of accountable physician directors of applicable resuscitation teams. Regardless of the device used, recognition of proper placement remains the most important aspect of using any invasive airway device. Therefore, proper training and expert medical supervision probably have more influence on the successful use and impact of these devices than any other factors related to the devices themselves. Future training efforts would be most useful if directed at proper endotracheal intubation training and development of improved basic ventilatory skills. Nevertheless, additional controlled, direct-comparison studies of the PTL and ETC devices are recommended and should be conducted in properly supervised emergency medical services systems.
The place of the laryngeal mask in emergency airway management by nonanaesthetists has yet to be established. We have compared the tidal volume achieved by nurses during hand ventilation using standard resuscitation equipment with a facemask, with or without a Guedel airway, and following placement of a laryngeal mask in the same patients. The tidal volumes measured while using the laryngeal mask were significantly greater (p < 0.01) than those measured during facemask ventilation.
Ten volunteers, with no previous experience of resuscitation, were formally trained in the use of the laryngeal mask airway and the oropharyngeal airway (Guedel), bag and facemask for manual ventilation of the lungs in 104 fit, anaesthetised adults. They then used both airways in turn. The order of insertion was randomly allocated, and the times taken for insertion were also recorded. Ventilation for each airway was deemed to be successful if an increase in end-tidal carbon dioxide partial pressure did not occur and arterial oxygen saturation remained greater than 90%. Success rates for the laryngeal mask airway and the Guedel airway, bag and facemask were 87% and 43% respectively (p < 0.001) and the average insertion times were 27.4 s (SEM 1.5) and 15.8 s (SEM 0.50) (no significant difference), respectively. The laryngeal mask airway proved to be easier to use for manual ventilation than the Guedel airway, bag and mask for inexperienced personnel who had received a period of formal training in both techniques.
Observers trained in basic life support assessed chest rise in 34 patients who were anaesthetised and paralysed and whose lungs were being mechanically ventilated prior to routine surgery. Making 67 independent assessments, the observers indicated the tidal volume that they considered produced adequate chest rise for resuscitation. The mean tidal volume perceived to be adequate was 384 ml with 95% confidence limits of 362-406 ml. The perceived volumes correlated with the Body Mass Index. Guidelines by various authorities recommend that tidal volumes sufficient to make the chest rise normally should be used during resuscitation. The volumes perceived as adequate by the observers are much lower than the numerical values recommended by the American Heart Association (800-1200 ml). High tidal volumes are associated with an increased risk of gastric regurgitation in patients with an unprotected airway, CO2 delivery to the lungs is likely to be low during cardiac arrest obviating the need for high tidal volumes. In the light of present knowledge and the findings in this study, we would recommend that resuscitation training manikins are recalibrated to indicate satisfactory ventilation at tidal volumes of 400-600 ml. These volumes should reduce the risk of gastric inflation and permit more chest compressions to be carried out in a minute because the ventilation fraction of the CPR sequence is shorter. Adequate CO2 elimination should still be assured.
The use of laryngeal mask airway (LMA), size 3 or 4, and endotracheal tube (ETT) 8.0 mm was studied comparatively to determine the adequacy of respiratory function during positive pressure ventilation (PPV) by applying a series of given peak inspiratory pressures (PIPs) of 10.0, 12.5, 15.0, 17.5, 20.0 and 30.0 cm H2O. Eleven anesthetised patients underwent a double comparative trial. First they were ventilated via the LMA and afterwards via the ETT. Tidal volume (VT), dynamic compliance, end-tidal carbon dioxide and peripheral oxygen saturation were recorded in a supine position, before skin incision. Higher values of VT (1.7 mk.kg-1) were expired via the LMA compared with ETT when a given PIP of less than 20 cmH2O was applied. LMA as opposed to ETT secured normocapnia during PPV with low PIPs.
The effect of withdrawing the resident anaesthesiologist from the cardiopulmonary resuscitation (CPR) team was audited over a 1-year period in a 407-bed hospital in which nurses had been trained in the use of the laryngeal mask airway (LMA) as a first response airway in CPR. The data were compared to those of the previous year, which are shown in parentheses. During the audit period, there were 115 (79) calls to 115 (79) patients; the immediate airway was secured using a mask bag valve assembly in 75 (49) episodes, the Laerdal pocket mask in 2 (2) episodes, the LMA in 64 (2) and the endotracheal tube in 20 (57). Return of spontaneous circulation occurred in 61% (36%). There were no instances of failure to maintain the immediate airway during the audit period. Initial results suggest that an anaesthesiologist may not be essential for the provision of an immediate airway in patients requiring CPR.
This retrospective study was designed to determine the choice of airway devices used for nontraumatic, out-of-hospital cardiac arrest patients and to evaluate the success and failure of insertion and airway control/ventilation by three airway adjuncts, the Combitube, the esophageal gastric tube airway (EGTA), and the laryngeal mask (LM), which were used in conjunction with the bag-valve-mask (BVM) by emergency life-saving technicians (ELSTs) in Japan.
A survey of 1,085 ELSTs was performed to identify the type of airway devices, the success rates of airway insertion, the effectiveness of airway control/ventilation in comparison with the BVM prior to each airway insertion, and associated complications. The type of education for airway skills was also surveyed.
1,079 surveys were returned and 12,020 cases of cardiac arrest were studied. Choice of airway devices: BVM, 7,180 cases; EGTA, 545 cases; Combitube, 1,594 cases; and LM, 2,701 cases. Successful insertion rates on the first attempt: EGTA, 82.7%; Combitube, 82.4%; and LM, 72.5% (p < 0.0001). Failed insertions: EGTA, 8.2%; Combitube, 6.9%; and LM, 10.5% (p < 0.0001). Successful ventilation: EGTA, 71.0%; Combitube, 78.9%; and LM, 71.5% (p < 0.0004). Six cases of aspiration were reported in the LM group, whereas nine cases of soft-tissue injuries, including esophageal perforation, were reported in the Combitube group. 17.8% had vomited either prior or during airway placement.
The Combitube appears to be the most appropriate choice among the airway devices examined. However, serious injuries to the tissues, though they rarely occurred in the study, remain a major concern.
A prehospital study was conducted to assess and compare three alternative airway devices and the oral airway for use by non-Advanced Life Support emergency medical assistants (EMAs).
A modified randomized crossover design was used. The Pharyngeal Tracheal Lumen Airway (PTL), the laryngeal mask (LM), and the esophageal tracheal Combitube (Combi) were compared objectively for success of insertion, ventilation, and arterial blood gas and spirometry measurements performed upon hospital arrival. Subjective assessment was carried out by EMAs and receiving physicians at the time of device use, and an eight-question comparative evaluation of all devices was completed by EMAs at study conclusion. A comparative cost analysis was performed. Operating room training was compared with mannequin training for the LM. Autopsy findings and survival to hospital discharge were analyzed. The study took place in four non-ALS communities over four and a half years, and involved 470 patients in cardiac and/or respiratory arrest. EMAs had automatic external defibrillator training but no endotracheal intubation skills.
Successful insertion and ventilation: Combi, 86%; PTL, 82%; LM, 73% (p = 0.048). No significant difference was found for objective measurements of ventilatory effectiveness (ABGs and spirometry). Significant comparative differences in subjective evaluation were found.
The PTL, LM, and Combi appear to offer substantial advances over the OA/BVM system. Although the most costly, the Combitube was associated with the least problems with ventilation and was the most preferred by a majority of EMAs.
The risk of gastric regurgitation and subsequent pulmonary aspiration is a recognised complication of cardiac arrest--a risk which may be further increased by the resuscitative procedure itself. The purpose of this study was to compare the incidence of gastric regurgitation between the bag valve mask (BVM) and laryngeal mask airway (LMA). The resuscitation data collection forms of 996 patients who underwent in-hospital cardiopulmonary resuscitation over a 3.5 year period were reviewed. Of these, 199 patients were excluded from the study because there was no airway management involving a BVM or LMA. The incidence and timing of regurgitation was studied in the remaining 797 patients. Regurgitation was recorded to have occurred at some stage in 180 of these patients (22.6%). However, 84 regurgitated prior to CPR (46.7% of those patients who regurgitated). These patients were excluded from further analysis as regurgitation could not have been affected by any form of ventilation. Of the remaining 713 patients, BVM ventilation was used in 636 cases. In 170 of these the LMA was also used following the BVM. Where the patient was ventilated with the BVM alone or BVM followed by ETT the incidence of regurgitation during CPR was 12.4%. The LMA was used during resuscitation in 256 cases of which 170 had BVM ventilation prior to the LMA. Where the patient was ventilated with the LMA alone or LMA followed by ETT the incidence of regurgitation during CPR was 3.5%. The study confirms experience reported in earlier studies that when an LMA is used as a first line airway device, regurgitation is relatively uncommon.
Mask ventilation is a procedure routinely used in emergency medicine. Potential hazards are inadequate alveolar ventilation and inflation of the stomach with air, leading to subsequent regurgitation and aspiration. The aim of this study was to measure lung function and gastric inflation pressures during mask ventilation.
For this purpose, 31 patients scheduled for routine urological procedures were studied during induction of anesthesia. Lung function was assessed by recording respiratory flow and pressure directly at the face mask. Gastric inflation was observed with a microphone taped to the epigastric area.
Gastric inflation occurred in 22 of the 31 patients. Mean gastric inflation pressure was 27.5 +/- 6.55 cm H2O, mean compliance was 67 +/- 24.1 ml/cm H2O, mean resistance was 17.4 +/- 6.41 cm H2O/L/sec, and the mean respiratory time constant was 1.1 +/- 0.26 seconds.
These data suggest that inspiratory pressure be limited to 20 cm H2O, and that an inspiratory time of at least four times the respiratory time constant be allowed. Monitoring airway pressure and gastric inflation is a simple technique that may improve the safe-ty of patients during mask ventilation.
Airway management takes precedence regardless of what type of life support is taking place. The gold standard for airway control and ventilation in the hands of the experienced paramedic remains unarguably the endotracheal tube. Unfortunately, laryngoscopy and endotracheal intubation require a skilled provider who performs this procedure on a frequent basis. Special Operations corpsmen and medics receive training in the use of the endotracheal tube, but they use it infrequently. The use of alternative airways by Navy SEAL and Reconnaissance combat corpsmen has not been evaluated. Our objective was to compare the ability of Special Operations corpsmen to use the endotracheal tube (ETT), laryngeal mask airway (LMA), and esophageal-tracheal combitube (ETC) under combat conditions.
This study used a prospective, randomized, crossover design. Twelve Navy SEAL or Reconnaissance combat corpsmen participated in a 2-week Advanced Battlefield Trauma course. During the first week, instruction included the use of ETT, LMA, and ETC, viewing of videotapes for ETC and LMA, and mannequin training. The Special Operations corpsmen were required to reliably insert each airway within 40 seconds. During the second week, participants dealt with a number of active combat trauma scenarios under fire in combat conditions. Each SEAL or Reconnaissance corpsman was asked to control his "casualty's" airway with a randomized device. All participants were evaluated in the use of each of the three airways.
Thirty-six airway insertions were evaluated. No failures occurred. All incorrect placements were detected and corrected. Mean time to place the ETT was 36.5 seconds versus 40.0 seconds for the ETC. The LMA insertion time of 22.3 seconds was significantly shorter than the other times (p < 0.05). The mean number of attempts per device was similar with all devices: LMA (1.17), ETC (1.17), and ETT (1.25).
The Special Operations corpsmen easily learned how to use the ETC and LMA. In this study, they showed the ability to appropriately use the ETT as well as the ETC and LMA. For SEAL corpsmen, the alternative airways should not replace the ETT; however, on occasion an advanced combat casualty care provider may not be able to use the laryngoscope or may be unable to place the ETT. The LMA and ETC are useful alternatives in this situation. If none of these airways are feasible, cricothyrotomy remains an option. Regardless of the airway device, refresher training must take place frequently.
Endtidal CO2 (PECO2) and arterial blood gas tensions were compared between laryngeal mask (LMA) and face mask (FM) ventilation in paediatric outpatients. Following premedication with midazolam, anaesthesia was induced with either thiopentone or isoflurane and atracurium. Anaesthesia was maintained with N2O, O2 and isoflurane. Manually controlled ventilation was applied with a nonrebreathing system. Both PECO2 and arterial blood gas tensions were measured at 5 and 15 min after skin incision. The mean PaCO2 values in the LMA group were 36.6+/-7.4 and 37.5+/-6.4 mmHg and PaCO2 -PECO2 were 1. 8+/-2.4 and 2.5+/-3.3 mmHg, respectively. The mean PaCO2 values in the FM group were 41.3+/-8.1 and 43.4+/-8.9 mmHg; and PaCO2 -PECO2 were 5.3+/-3.6 and 8.8+/-7.0 mmHg, respectively. These values were lower in the LMA group (P< 0.05). We have concluded that monitoring of PECO2 is more reliable for estimating blood gas values during controlled ventilation with a LMA than a face mask.
Gastric inflation and subsequent regurgitation are a potential risk of ventilation during cardiopulmonary resuscitation (CPR). In respect of recent investigations, principal respiratory components such as respiratory system compliance, resistance and lower esophageal sphincter pressure were adapted according to CPR situations. The purpose of our study was to assess lung ventilation and gastric inflation when performing ventilation with bag-valve-mask, laryngeal mask airway, and combitube in a bench model simulating an unintubated cardiac arrest patient. Twenty-one student nurses, without any experience in basic life support measures, ventilated the bench model with all three devices. Mean ( +/- S.D.) gastric inflation with the laryngeal mask airway (seven cases) was significantly lower than with the bag-valve-mask (0.6 +/- 0.8 vs 3.0 +/- 2.11 min(-1), P < 0.01). There was no gastric inflation when ventilation was performed with the combitube. Only seven of 21 volunteers exceeded 1-min lung volumes of > 5 1 when using the bag-valve-mask, whereas mean (+/-S.D.) 1-min lung volumes with both laryngeal mask airway and combitube were significantly higher (laryngeal mask airway 15.0+/-6.61, combitube 16.6 +/- 6.81 vs bag-valve-mask 4.8 +/- 2.71, P < 0.01). The time for insertion was significantly faster with both bag-valve-mask and laryngeal mask airway compared with the combitube (median: bag valve mask 22 s, laryngeal mask airway 37 s vs combitube 70 s, P < 0.01). This may tip the scales towards using the laryngeal mask airway during basic life support airway management. In conclusion, our data suggests that both laryngeal mask airway and combitube may be appropriate alternatives for airway management in the first few minutes of CPR.
Gastric inflation and subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). Recent investigations suggested that use of a paediatric self-inflating bag may reduce stomach inflation while ensuring sufficient lung ventilation. The purpose of our study was to examine whether use of a paediatric self-inflating bag in association with laryngeal mask airway, combitube, and bag-valve-face mask may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Sixteen intensive care unit registered nurses volunteered for our study. Use of a paediatric versus adult self-inflating bag resulted in a significantly (P < 0.01) lower mean (+/- S.D.) tidal lung volume with both the laryngeal mask airway and combitube (laryngeal mask airway 349 +/- 149 ml versus 725 +/- 266 ml, combitube 389 +/- 113 ml versus 1061 +/- 451 ml). Lung tidal volumes were below the European Resuscitation Council recommendation with both self-inflatable bags in the bag-valve-face mask group (paediatric versus adult self-inflatable bag 256 +/- 77 ml versus 334 +/- 125 ml). Esophageal tidal volumes were significantly (P < 0.05) lower using the paediatric self-inflatable bag in the bag-valve-face mask group; almost no gastric inflation occurred with the laryngeal mask airway, and none with the combitube. In conclusion, use of the paediatric self-inflating bag may reduce gastric inflation, but measured lung tidal volumes are below the European Resuscitation Council recommendation when used with either, the laryngeal mask airway, combitube, or bag-valve-face mask.
This study evaluates spontaneous breathing and CO2-monitoring under sevoflurane anesthesia with a cuffed oropharyngeal (COPA) or laryngeal mask (LMA) as airway. Forty patients (ASA I-II) scheduled for varicose vein surgery were given 2 mg.kg-1 propofol for insertion of a COPA or a LMA. Anesthesia was maintained with sevoflurane at 2.5 vol% in 40/60% O2/N2O, while the patients breathed spontaneously. Arterial and end-tidal CO2 partial pressures (PaCO2, PE'CO2), respiratory rate (RR), tidal volume (VT) and expired minute volume (EMV) were recorded at different times before and during the procedure. The dead space (VD) was calculated from the modified Bohr equation. The PaCO2 and the PE'CO2 were generally lower in the LMA group as compared to the COPA group during most of the procedure. EMV was also higher in the LMA group as compared to the COPA group. This difference becomes statistically significant 5 min. before the end of surgery (6.22 +/- 0.34 vs. 5.23 +/- 0.39 L.min-1). RR was consistently higher in the LMA group, while VT and VD were similar. Correlation of PE'CO2 and PaCO2 was 0.87 when measured in the COPA group and 0.88 in the LMA group. The prediction of PaCO2 by PE'CO2 was more sensitive in the LMA group as compared to the COPA group. We conclude that spontaneous breathing is better with the LMA.
The aim of this study was to compare ease of ventilation of a cardiopulmonary resuscitation manikin using a cuffed oropharyngeal airway (COPA), a laryngeal mask airway (LMA) and a face mask, by two groups of people with different levels of earlier experience in cardiopulmonary resuscitation (CPR). Enrolled were, 108 people identified as experienced (54), or inexperienced (54), in CPR. Training equipment included a manikin, a COPA (n=10), an LMA (n=4), a face mask (n=4) and self-inflating bag-valve device. The same investigator explained the theoretical use and practice of the three techniques with the subjects in groups of three. The variables recorded were the number of attempts needed to achieve correct placement (and a tidal volume of 200 ml, was achieved), the insertion time for the COPA and the LMA, and the average time taken to achieve the first ten correct ventilations. The face mask and LMA required fewer attempts for correct placement than did the COPA. The LMA also took less time to insert than the COPA. The face mask required a significantly shorter total time with all attempts and the mean time of placement and time to achieve ten correct ventilations was shorter than with either the LMA or the COPA (P=0.0001). We conclude that the face mask offers an easier and quicker way to provide ventilation for CPR manikins than does the COPA or the LMA. Earlier experience affects the ease of insertion of the LMA and the total time needed to achieve effective ventilation.
The most appropriate airway device for use in EMS systems staffed by basic skilled EMTs with (EMT-Ds) or without (EMT-Bs) defibrillation capabilities is still a matter of debate. The purpose of this study was to assess the feasibility, safety and effectiveness of the Esophageal Tracheal Combitube (ETC) when used by EMT-Ds in cardiorespiratory arrest patients of all etiologies. The EMTs had automatic external defibrillator (AED) training but no prior advanced airway technique skills. The prehospital intervention was reviewed using the EMTs cardiac arrest report, the AED tape recording of the event and the assessment of the receiving emergency physician. The patients' hospital records and autopsy report were reviewed in search of complications. Eight hundred and thirty-one adult cardiac arrest patients were studied. Placement was successful in 725 (95.4%) of the 760 patients where it was attempted and ventilation was successful in 695 (91.4%). Immediate complications encountered, but not necessarily related to the use of the ETC, were; subcutaneous emphysema (18), tension pneumothorax (5), blood in the oropharynx (15), and swelling of the pharynx (three). An autopsy was done in 133 patients; no esophageal lesions or significant injury to the airway structures were observed. Our results suggest that EMT-Ds can use the ETC for control of the airway and ventilation in cardiorespiratory arrest patients safely and effectively.
The standard laryngeal mask airway LMA-Classic is recommended in the ILCOR guidelines as alternative to facemask and tracheal tube during cardiopulmonary resuscitation. LMA-Unique, LMA-Fastrach and LMA-ProSeal are additional variants that are compared with the standard LMA in a resuscitation model.
Tidal volumes, chest compressions and signs of gastric inflation are measured in a standardized resuscitation model (Ambu Cardiac Care Trainer with notebook and thumper). Ten 3-minute resuscitation cycles were performed with facemask and all LMAs (Classic, Unique, Fastrach, ProSeal, all size 4) with a ventilation : compression ratio of 2:15. To allow comparison with tracheal tube and to judge safety margins, another ten resuscitation cycles were performed with tracheal tube and all laryngeal masks with continuous chest compressions after two initial ventilations. The bag-valve device used for ventilation was replaced by an automatic transport ventilator in a third series with continuous chest compressions. Cuff pressures were set at 80 cm H2O.
During interrupted chest compressions, adequate ventilation was possible with all devices. Tidal volumes for facemask, LMA-Fastrach and LMA-ProSeal were significantly (p < 0.001) higher than with LMA- Classic and LMA-Unique. During continuous chest compressions, significant differences (p < 0.001) occurred when comparing tracheal tube, Fastrach and ProSeal with the other two laryngeal mask airways, which did not reach recommended tidal volumes. During ventilation with the automatic transport ventilator, values for all devices except LMA-ProSeal dropped significantly, adequate ventilation was possible with tracheal tube, Fastrach and ProSeal. Signs of gastric inflation were found during ventilation with facemask and - to a lesser extent - with LMA-Classic.
In the resuscitation model chosen, all laryngeal mask airways are possible alternatives for ventilation during cardiopulmonary resuscitation. The new LMA-ProSeal and also the LMA-Fastrach allow higher tidal volumes even during elevated intrathoracic pressures caused by continuous chest compressions, performing superior to the standard laryngeal mask airway. For inclusion of these devices in the ILCOR guidelines, further research in patients is warranted.
This prospective randomised study was performed to compare the use of the Esophageal-Tracheal Combitube(R) (ETC; Tyco Healthcare, Mansfield, MA; http://www.combitube.org) with a conventional tracheal airway (ETA) for airway management by experienced physicians of the Emergency Medical Services System of the City of Vienna in the prehospital setting. Access to the patient's head, time of arrival of the ambulance, ease of insertion, time of insertion, potential substitution by the alternate airway, efficacy of adrenaline (epinephrine) administered via the airway, survival to the intensive care unit (ICU) ward and survival to discharge from the hospital were evaluated. One hundred and seventy-two non-traumatic cardiac arrest patients (131 males, 41 females) were enrolled in this study during a 12 months period. In 83 patients (48.3%), the conventional ETA (group 1) was used for the initial intubation attempt which was successful in 78 patients (94%). The remaining five patients of group 1 could not be intubated with an ETA, but were successfully managed with the ETC. Eighty-nine patients (51.7%) were intubated with the ETC (group 2) as first choice (79 in oesophageal position (89%); eight in tracheal position: (9%)), which was successful in 87 (98%) patients. The remaining two patients in group 2 (2%) were successfully managed with the ETA. Success of intubation and ventilation with ETC was comparable to the ETA. Recorded time of insertion was shorter with the ETC versus ETA (P<0.05). The Combitube worked well in cases of difficult access to the patient's head and in bleeding and vomiting patients. Both devices served as successful substitutes for each other. Adrenaline (epinephrine) applied via ETC with a 10-fold dosage was as effective as via the conventional ETA. To our knowledge this is the first study using physicians comparing ETC and ETA in the prehospital setting.
The aim of this case-control study was to determine whether unplanned resuscitation using a laryngeal mask airway (LMA) is suitable for neonates delivered by elective cesarean section, a procedure known to carry a risk of inadequate physiological response to birth with a consequent adverse respiratory outcome. During a 3-year period, from January 1998 to December 2000, all newborns delivered by elective cesarean section at term were compared with the next infant born vaginally in the same maternity unit (level III center). The two groups were matched for gestational age >37 weeks. The requirement for resuscitation with positive-pressure ventilation (PPV) using either the LMA or an endotracheal tube (ETT), together with the occurrence of an adverse neonatal outcome, was recorded and analyzed in the cesarean section and vaginal delivery groups. During this time 1,284 at-term elective cesarean sections were performed. 3% (n = 43) of the cesarean section deliveries and 1.4% (n = 18) of the vaginal controls required PPV resuscitation by LMA or ETT, a significant difference (OR 1.26; 95% CI 2.38–5.1; p
The optimal tidal and minute ventilation during cardiopulmonary resuscitation (CPR) is not known. In the present study seven adult, non-traumatic, out-of-hospital cardiac arrest patients were intubated and mechanically ventilated at 12 min(-1) with 100% oxygen and a tidal volume of 700 ml (10 +/- 2 ml kg(-1)). Arterial blood gas samples were analysed after 6-8 min of unsuccessful resuscitation and mechanical ventilation. Mean PaCO2 was 5.2 +/- 1.3 kPa and mean PaO2 30.7 +/- 17.2 kPa. The patient with the highest (14 ml kg(-1)) and lowest (8 ml kg(-1)) tidal volumes per kg had the lowest and highest PaCO2 values of 2.6 and 6.8 kPa, respectively. Linear regression analysis confirmed a significant correlation between arterial pCO2 and tidal volume in ml/kg, r2 = 0.87. We conclude that aiming for an estimated ventilation of 10 ml kg(-1) tidal volume at frequency of 12 min(-1) might be expected to achieve normocapnia during ALS.
The study aims to compare the frequency of ideal anatomic placement of the laryngeal mask airway (LMA) using the traditional blind insertion approach with one where placement was facilitated by the use of a laryngoscope (epiglottoscopy).
A prospective comparison of 132 patients divided into 2 groups (38 with the blind technique and 94 with the direct technique) were evaluated with 2 airway assessment methods, Wilson and Mallampati. We also considered whether there was a relationship between these criteria and the successful placement into an ideal position. Other variables were considered, including breathing airflow dynamics, body size, and skill level of the anesthesia care provider. Five placement visual ordinals were used to grade the LMA position.
All of the patients studied except one had good to excellent breathing patterns after LMA placement. Statistically more patients who had ideal to nearly ideal placement position of the LMA were placed under direct epiglottoscopy than when placed by the classic blind technique. The position of the LMA was assessed by fiberoptic examination through an attachment between the LMA and the anesthetic circuit. Eighty-six of 94 patients (91.5%) in the direct visual placement group had ideal position compared with 16 of 38 (42%) in the blind placement group. Both groups had more successful placement than any other studies by comparison. Even several obese patients were successfully treated by either technique, and even the inexperienced anesthesia care provider could place the LMA with considerable accuracy.
One hundred thirty-one of 132 patients had no airway difficulties after LMA placement with either blind (classic) or direct visual epiglottoscopy (laryngoscopy). A fiberoptic scope proved to be a valuable tool to assess the results. When ideal placement is either highly desirable or necessary, the direct visual technique is considered to be a better choice for placement than the blind, classic method.
Endotracheal intubation is the gold standard for providing emergency ventilation, but acquiring and maintaining intubation skills may be difficult. Recent reports indicate that even in urban emergency medical services with a high call volume, esophageal intubations were observed, requiring either perfect intubation skills or development of alternatives for emergency ventilation.
Simulated emergency ventilation in apneic patients employing four different airway devices that used small tidal volumes.
University hospital operating room.
Forty-eight ASA I/II patients who signed written informed consent before being enrolled into the study.
In healthy adult patients without underlying respiratory or cardiac disease who were breathing room air before undergoing routine induction of surgery, 12 experienced professional paramedics inserted either a laryngeal mask airway (n = 12), Combitube (n = 12), or cuffed oropharyngeal airway (n = 12) or placed a face mask (n = 12) before providing ventilation with a pediatric (maximum volume, 700 mL) self-inflating bag with 100% oxygen for 3 mins.
In three of 12 cuffed oropharyngeal airway patients, two of 12 laryngeal mask airway patients, and one of 12 Combitube patients, oxygen saturation fell below 90% during airway device insertion, and the experiment was terminated; no oxygenation failures occurred with the bag-valve-mask. Oxygen saturation decreased significantly (p <.05) during insertion of the Combitube and laryngeal mask but not with the bag-valve-mask and cuffed oropharyngeal airway; however, oxygen saturation increased after 1 min of ventilation with 100% oxygen. No differences in tidal lung volumes were observed between airway devices.
Paramedics were able to employ the laryngeal mask airway, Combitube, and cuffed oropharyngeal airway in apneic patients with normal lung compliance and airways. In this population, bag-valve-mask ventilation was the most simple and successful strategy. Small tidal volumes applied with a pediatric self-inflating bag and 100% oxygen resulted in adequate oxygenation and ventilation.
Purpose:
The guidelines for cardiopulmonary resuscitation (CPR) have been in place for decades; but despite their international scope and periodic updates, there has been little improvement in survival rates in out-of-hospital cardiac arrest for patients who did not receive early defibrillation. The Emergency Medical Service directors in 2 rural Wisconsin counties initiated a new protocol for the pre-hospital management of adult cardiac arrest victims in an attempt to improve survival rates. The results observed after implementation of this protocol are presented and compared with those observed during a three-year period that preceded initiation of the project.
Methods:
The protocol, based upon the principles of cardiocerebral resuscitation, was significantly different from the standard CPR protocol. A major objective was to minimize interruptions of chest compressions. Each defibrillation, including the first, was preceded by 200 uninterrupted chest compressions. Single shocks, rather than stacked shocks, were utilized. Post shock rhythm and pulse checks were eliminated, and chest compressions were resumed immediately after a shock was delivered. Initial airway management was limited to an oral pharyngeal device and supplemental oxygen. If the arrest was witnessed, assisted ventilations and intubation were delayed until either a return of spontaneous circulation or until three series of "compressions + analysis +/- shock" were completed.
Results:
In the 3 years preceding the change in protocol, where standard CPR was utilized, there were 92 witnessed out-of-hospital adult cardiac arrests with an initially shockable rhythm. Eighteen patients survived, and 14 of 92 (15%) were neurologically intact. After implementing the new protocol in early 2004, there were 33 witnessed out-of-hospital adult cardiac arrests with an initially shockable rhythm. Nineteen survived, and 16 of 33 (48%) were neurologically normal. Differences in both total and neurologically normal survival are significant (chi-squared = 0.001).
Conclusion:
Instituting the new cardiocerebral resuscitation protocol for managing prehospital cardiac arrest improved survival of adult patients with witnessed cardiac arrest and an initially shockable rhythm.
Two randomized studies have shown a neurological benefit of therapeutic hypothermia in comatose survivors after out-of-hospital cardiac arrest, but there are no studies of the cardiac neurohormone of B-type natriuretic peptide (BNP) in patients treated with hypothermia.
A prospective study was conducted of 109 comatose patients who were treated with mild hypothermia after out-of-hospital sudden cardiac arrest due to cardiac causes and whose BNP level was measured on arrival at the emergency room. The primary endpoint was a favorable neurological outcome at the time of hospital discharge. A total of 45 of the 109 patients had a favorable neurological outcome. The unadjusted rate of a favorable neurological outcome decreased in a stepwise fashion among patients in increasing quartiles of BNP level (p<0.001) and this association remained significant in subgroups of patients. The BNP cutoff value of 80 pg/ml for a favorable neurological outcome had an accuracy of 87.2%. In the multiple logistic-regression analysis, a BNP level of 80 pg/ml or less was an independent predictor of favorable neurological outcome.
The measurement of BNP was found to provide valuable information regarding the neurological outcome of comatose survivors treated with mild hypothermia after out-of-hospital cardiac arrest due to cardiac causes.
The use of automated external defibrillators (AEDs) has increased the number of survivors of out-of-hospital cardiac arrest. The AED has a high specificity and moderately high sensitivity in detecting rhythms appropriately treated by defibrillation. However, a few shockable rhythms are misdiagnosed by the AED. Two cases of inappropriate analyses by AEDs in patients with in-hospital ventricular fibrillation are presented. In the first case, the AED failed to recognize ventricular fibrillation because of the presence of pacemaker spikes. In the second case, the fine ventricular fibrillation and the presence of artifacts were suspected as the causes of inappropriate analysis by the AED. Both patients were resuscitated by advanced cardiovascular life support with a manual defibrillator. Trained healthcare providers should be aware of the limitations of AED in specific situations.
Matsudo City Hospital, Chiba; Naoki Kozima: Showa General Hospital
- Naohiko Fugiyoshi
Naohiko Fugiyoshi: Matsudo City Hospital, Chiba; Naoki Kozima: Showa
General Hospital, Tokyo; Naoshige Harada: Nihon Medical School, Tokyo;
Ohtawara Red Cross Hospital, Tochigi; Yoshihide Nakagawa: Tokai University Hospital, Kanagawa; Yoshiki Tokuyasu: Tokyo Metropolitan Hiroo General Hospital, Tokyo; Yoshiyuki Haga: Saitama Municipal Hospital Emergency and Critical Care Center
- Yasuyuki Miyahara
Yasuyuki Miyahara: Ohtawara Red Cross Hospital, Tochigi; Yoshihide
Nakagawa: Tokai University Hospital, Kanagawa; Yoshiki Tokuyasu:
Tokyo Metropolitan Hiroo General Hospital, Tokyo; Yoshiyuki Haga:
Saitama Municipal Hospital Emergency and Critical Care Center, Saitama;