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Evaluation of the newborn's blood gas status. National Academy of Clinical Biochemistry
Abstract
Blood gas measurements and complementary, noninvasive monitoring techniques provide the clinician with information essential to patient assessment, therapeutic decision making, and prognostication. Blood gas measurements are as important for ill newborns as for other critically ill patients, but rapidly changing physiology, difficult access to arterial and mixed venous sampling sites, and small blood volumes present unique challenges. This paper discusses considerations for interpretation of blood gases in the newborn period. Blood gas measurements and noninvasive estimations provide important information about oxygenation. The general goals of oxygen therapy in the neonate are to maintain adequate arterial PaO2 and SaO2, and to minimize cardiac work and the work of breathing. Pulse oximetry and transcutaneous oxygen monitoring are extraordinarily useful techniques of estimating and noninvasively monitoring the neonate's oxygenation, but each method has limitations. Arterial blood gas determinations of pCO2 provide the most accurate determinations of the adequacy of alveolar ventilation, but capillary, transcutaneous, and end-tidal techniques are also useful. An approach to and examples of acid-base disorders are presented. Three hemoglobin variants relevant to the newborn are considered: fetal hemoglobin, carboxyhemoglobin, and methemoglobin. Blood gases obtained in the immediate perinatal period can help assess perinatal asphyxia, but particular attention must be paid to the sampling site, the time of life, and the possible and proven diagnoses.
... These methods can accurately assess blood gas concentrations, but only at a single time point. The original method of performing blood gas analysis is blood sampling, the standard by which all other methods are compared [59], [62], [63]. In this method, blood is physically drawn from a patient and tested for oxygen and carbon dioxide. ...
... The other two methods, VBG and CBG, fail to provide an accurate measure of PaO 2 , which is directly related to how well tissues and organs are oxygenated. ABG also assesses the acid-base status and evaluates the efficacy of ventilation [46], [62], [63], [65]. An illustration of a peripheral ABG monitoring system on an infant appears in Fig. 2. ...
... 2) Noninvasive Contact Methods: The last two decades has witnessed an innovative shift towards continuous, noninvasive monitoring methods, capable of analyzing oxygen and carbon dioxide measurements continuously and generating real-time data on respiratory changes in patients [62], [63], [65], [70], [99]. These methods use a large variety of sensing mechanisms. ...
In this article, we present current methodologies, available technologies, and demands for monitoring various respiratory parameters. We discuss the importance of noninvasive techniques for remote and continuous monitoring and challenges involved in the current "smart and connected health" era. We conducted an extensive literature review on the medical significance of monitoring respiratory vital parameters, along with the current methods and solutions with their respective advantages and disadvantages. We discuss the challenges of developing a noninvasive, wearable, wireless system that continuously monitors respiration parameters and opportunities in the field and then determines the requirements of a state-of-the-art system. Noninvasive techniques provide a significant amount of medical information for a continuous patient monitoring system. Contact methods offer more advantages than non-contact methods; however, reducing the size and power of contact methods is critical for enabling a wearable, wireless medical monitoring system. Continuous and accurate remote monitoring, along with other physiological data, can help caregivers improve the quality of care and allow patients greater freedom outside the hospital. Such monitoring systems could lead to highly tailored treatment plans, shorten patient stays at medical facilities, and reduce the cost of treatment.
... The goals of oxygen therapy in neonate are (i) to maintain adequate partial pressure of oxygen in arterial blood (PaO 2 ), (ii) to minimize the cardiac work and (iii) to minimize the work of breathing 11 . It is important to realize that optimal oxygenation will result in different PaO 2 goals for different sick neonates. ...
... Oxygen should be administered only when indicated, given in the lowest ambient concentration and should be stopped as soon as its use is considered unnecessary 3 . Most commonly, premature infants in respiratory failure should have PaO 2 values between 50-80 mmHg 11 . A PaO 2 values of <40 mmHg and >80 mmHg is also regarded as 'low' and 'high' PaO 2 values by neonatologists 12 . ...
... A PaO 2 values of <40 mmHg and >80 mmHg is also regarded as 'low' and 'high' PaO 2 values by neonatologists 12 . Maintenance of partial pressure of oxygen within such range minimizes the chances of blindness caused by retinopathy 11 . In very low birth weight newborns, when treating with oxygen, a PaO 2 of 41 mmHg may be enough to saturate 90% of hemoglobin at a physiological pH 13 . ...
Introduction Oxygen is the most common drug used in neonatology worldwide 1. Inappropriate supplementation of oxygen may not decrease hypoxia or may lead to development of hyperoxia. Hypoxia may lead to pulmonary vasoconstriction, pulmonary hypertension, neurological and other organ damage 2. This condition may be associated with lethargy, cyanosis, hypothermia, fixed heart rate of 120/min or bradycardia, metabolic acidosis or unresponsiveness to therapy 3. Hyperoxia, on the other hand, produces complex physical and physiological stress 4. It produces free radical mediated cellular damage through lipid peroxidation, inactivation of enzymes, damage of DNA and structural protein. It is believed that a number of diseases in the newborn may occur as consequences of oxygen free radicals e.g. retinopathy of prematurity, bronchopulmonary dysplasia, necrotizing enterocolitis and patent ductus arteriosus etc 3 .
... The evaluation of blood gas analysis immediately after birth could therefore be useful in detecting the neonates needing special monitoring in the first weeks of life [4]. As reported for human babies, blood gas analysis is important for early evaluation of the health of a newborn [5], providing valuable diagnostic and prognostic information, essential to patient assessment and management. Blood gas analysis aims primarily to measure blood oxygen and carbon dioxide quantity, and pH. ...
... For this reason, in the present study, the period of observation was extended to 96 hours after birth. Arterial blood gas analysis represents the gold standard for the evaluation of the acid-base and respiratory status in newborn foals [17] and humans [5,[18][19][20]. However, this procedure is not free from complications such as arterial injuries, thrombosis with distal ischemia, hematoma, aneurysm, and more rarely, reflex sympathetic dystrophy [21,22]. ...
In neonatology, blood gas analysis is a useful tool in the evaluation of the health of newborns and plays a key role in early detection of critically ill subjects. Because blood gas analysis parameters have not previously been studied in any depth in donkey foals, this study was performed on 16 healthy Martina Franca donkey foals born after an uncomplicated delivery. Arterial and venous blood samples were collected at 5 minutes and at 12, 24, 72 and 96 hours of age. Blood gas analysis was performed by a portable analyzer, measuring arterial and venous total carbon dioxide (tCO2), carbon dioxide partial pressure (pCO2), oxygen partial pressure (pO2), oxygen saturation (sO2), bicarbonate (HCO3), base excess (BE), pH, and lactate (LT). Lower blood pH values, pO2 and sO2, and a higher level of lactate were found at birth in comparison with subsequent sampling times. This moderate acidotic profile disappeared at 12 hours, when all the parameters became constant until the end of the study period. As expected, significant differences between arterial and venous blood gas parameters related to the oxygenation, such as pO2 and sO2, and partially pCO2 were found, while tCO2, pH, BE, and LT were comparable in arterial and venous blood samples. For these latter parameters, the highly significant correlation between arterial and venous findings suggests that venous samples could be an acceptable alternative to the arterial sample for blood gas analysis in newborn donkey foals, when the oxygenation status of the patient is not the first goal of patient analysis.
... The analytical imprecision (CV) for each of the variables measured was either equal to or better than those recommended by Brouillete and Waxman [11] and Ehrmeyer et al. citing the CLIA [12]. The CVs were <0.06%, <2%, <5%, <1.3% and <2% for pH, pCO 2 , pO 2 , hemoglobin and ionized calcium, respectively. ...
... Most of the available studies reporting on blood gases are either done on infants in pediatric or neonatal intensive care units [17 -20]. Relevant to the group of infants included in the present study, Brouillette and Waxman [11] have published a review on blood gas measurements and complementary non-invasive monitoring techniques in normal term neonates from birth until 120 min of life. However, the arterial pH, pCO 2 , pO 2 and lactate values reported in the form of figures, stemmed from a textbook published in 1976 [21]. ...
Because biological data are instrument-dependent and because technology has evolved over the last two decades, the published capillary blood reference values for blood gases, lactate, ionized calcium (iCa) and glucose may not reflect the present day situation. Hence, we report such values for healthy term neonates at 48 +/- 12 h of life.
The Institution Ethics Review Board for Research on Human Subjects has accepted the protocol. Extra blood sample was obtained at the time heel-pricks were performed in the frame of the Quebec genetic screening program. One hundred twenty-six term neonates (39.6 +/- 1.2 weeks of gestation) were included in the study. pH, pO2, pCO2, lactate, ionized calcium and glucose were simultaneously measured with selective electrodes on the ABL 735 blood gas analyzer (Radiometer).
All variables exhibited a Gaussian distribution. Since there was no gender effect, all data were pooled.
... through air exchange in the alveoli, and the acid-based status of the blood [5]. The gold standard for measuring PaCO 2 is an arterial blood gas (ABG) analysis [6]- [8]. The major drawback of ABG sampling, however, is its invasiveness, accompanied by pain, and its limited ability to provide a brief and selective account of the potentially changing ventilatory status of critically ill patients [9], [10]. ...
Wearable smart health applications aim to continuously monitor critical physiological parameters without disrupting patients' daily activities, such as giving a blood sample for lab analysis. For example, the partial pressure of arterial carbon dioxide, the critical indicator of ventilation efficacy reflecting the respiratory and acid-base status of the human body, is measured invasively from the arteries. Therefore, it can momentarily be monitored in a clinical setting when the arterial blood sample is taken. Although a noninvasive surrogate method for estimating the partial pressure of arterial carbon dioxide exists (i.e., transcutaneous carbon dioxide monitoring), it is primarily limited to intensive care units and comes in the form of a large bedside device. Nevertheless, recent advancements in the luminescence sensing field have enabled a promising technology that can be incorporated into a wearable device for the continuous and remote monitoring of ventilation efficacy. In this review, we examine existing and nascent techniques for sensing transcutaneous carbon dioxide and highlight novel wearable transcutaneous carbon dioxide monitors by comparing their performance with the traditional bedside counterparts. We also discuss future directions of transcutaneous carbon dioxide monitoring in next-generation smart health applications.
... Therefore, acidemia and alkalemia are mutually exclusive conditions. [11] The approach to acidbase derangements emphasizes a search for the cause, rather than an immediate attempt to normalize the pH. Many disorders are mild and do not require treatment. ...
Background: Every year deranged acid-base physiology drives admission to a critical care arena for a vast number of neonates. The neonatal intensive care unit is a fundamental sector for the survival of high-risk newborns. The acid-base disorder must always be considered in the clinical setting. The clinician should, in most cases, be able to predict the type of acid-base imbalance before the blood gas is available. Arterial blood gases (ABG-s) are the gold standard for assessing the adequacy of oxygen delivery, ventilation, and pH. This study aimed to assess the frequency of acid-base derangements among neonates admitted to the intensive care unit. Material & Methods: This was an observational cohort study that was conducted in the Neonatal Intensive Care Unit (I.C.U.) of Dhaka Shishu Hospital, Dhaka, Bangladesh during the period from October 2009 to September 2010. In total 230 neonates admitted to the Neonatal Intensive Care Unit, after fulfilling the inclusion criteria were enrolled in this study as study subjects. For each baby, a detailed history was recorded in a questionnaire form (enclosed herewith) from the mother or other caregiver. It was filled up by the researcher himself containing history (including antenatal history), physical examinations and laboratory findings. Arterial blood gas analysis was done (in a clinical biochemistry laboratory using an automatic analyzer machine) for each neonate at admission and that report was recorded for this study. Results: Among the total study subjects, 127 newborn babies (55.2%) had acid-base imbalances. Mixed acidosis prevailed in the highest frequency (23.9%) Then metabolic acidosis cases were at 17.8% and respiratory acidosis was at 13.9%. Metabolic alkalosis and respiratory alkalosis were absent. Normal blood gas was observed in 44.3% of newborns. All the neonates with pH <7 were dead. After Chi-Square analysis (at df=1), we found a highly significant correlation between mortality outcome with pH <7.35, CO2 >45, HCO3 < 22 mol/l and Base deficit >-10. All modalities of acid-base imbalances were significantly associated with mortality. Conclusion: In this study, a significant number of neonates who were admitted to the intensive care unit, can develop acid-base derangement. Mixed acidosis was found in the highest frequency. Metabolic, respiratory and mixed acidosis all has a significant correlation with death in a NICU. Metabolic alkalosis and respiratory alkalosis were found absent at admission.
... Bu sebeple kan gazı analizi, teşhis ve tedaviye yardımcı olmak ve çeşitli geviş getiren hastalıklarının prognozunu belirlemek için veteriner hekimlere önemli bilgiler sunar (16). Kan gazı ölçümleri diğer hastalar kadar, yeni doğan hastalar için de önemlidir (17). Gebelik esnasında solunum, kardiyovasküler, renal, gastrointestinal ve sentral sinir sisteminde birçok anatomik ve fizyolojik değişiklikler meydana gelir (18,19). ...
Memelilerde gebelik döneminde, maternal ve fetal yapılar arasındaki madde alışverişi ile laktasyon periyodundaki süt sentezi, anne ve yavruda asit-baz, kan gazı ve elektrolit dengesinde farklılıklara neden olmaktadır. Çalışma C vitamininin farklı dozda uygulamalarının, gebelik ve laktasyon dönemindeki koyunlarda ve bunlardan doğacak kuzularda asit-baz ve elektrolit dengesi üzerindeki etkilerini araştırmak amacıyla yapıldı. Çalışmada toplam 48 adet Konya merinosu koyun ile bunlardan doğan 50 kuzu kullanıldı. Koyunlar dört gruba ayrıldı. Grup 1 (negatif (-) kontrol, n:8) ve Grup 2 (pozitif (+) kontrol, n:13)’deki koyunlara serum fizyolojik, Grup 3 (n:13) ve Grup 4 (n:14)’teki koyunlara ise gebeliğin 4. ayının başlamasıyla birlikte doğuma kadar her hafta sırasıyla 2.5 ml ve 5 ml C vitamini enjeksiyonu yapıldı. Gebe koyunlarda gruplar arası karşılaştırmalarda C vitamini uygulamasının pH (potansiyel hidrojen veya hidrojenin gücü), pCO2 (kısmi karbondioksit basıncı), cSO2 (oksijen doygunluğu) ve BE (b) (kan baz fazlalığı) parametreleri üzerine önemli bir etkisi olmazken; gebeliğin O. gününde pO2 (kısmi oksijen basıncı) parametresinde azalma, BE (ecf) (ekstrasellüler sıvı baz fazlalığı) parametresinde artma, gebeliğin 5. ayında pO2 parametresinde artma, cHCO3– (bikarbonat) ve TCO2 (toplam karbondioksit) parametrelerinde azalma, laktasyonun 1. ayında ise pO2, cHCO3–, BE (ecf) ve TCO2 parametrelerindeki artma istatistiki açıdan önemli bulundu. Kuzularda gruplar arası karşılaştırmalarda C vitamininin ölçülen parametreler üzerinde etkili olmadığı görüldü. Sonuç olarak; Konya merinosu koyunlarının gebelik ve laktasyon dönemlerinde, bazı kan gazı parametreleri üzerine C vitamini enjeksiyonunun etkili olduğu, bununla birlikte C vitamininin kan gazları üzerindeki etkisini daha iyi anlayabilmek için C vitamininin farklı doz ve uygulama yollarının denenebileceği kanaatine varıldı.
... Typically, a sample should be rejected when there is a high risk of reporting an unreliable result [9]. However, blood collection or re-correction is challenging in clinical practice, especially in newborns, young children, and other patients whose venous access is difficult (i.e., elderly or critically ill) [36,37]. Therefore, educating doctors and nurses who collect the samples may minimize the frequency of unsuitable specimens. ...
Objective
Hemolysis, icterus, and lipemia (HIL) of blood samples have been a concern in hospitals because they reflect pre-analytical processes' quality control. However, very few studies investigate the influence of patients' gender, age, and department, as well as sample-related turnaround time, on the incidence rate of HIL in fasting serum biochemistry specimens.MethodsA retrospective, descriptive study was conducted to investigate the incidence rate of HIL based on the HIL index in 501,612 fasting serum biochemistry specimens from January 2017 to May 2018 in a tertiary university hospital with 4,200 beds in Sichuan, southwest China. A subgroup analysis was conducted to evaluate the differences in the HIL incidence rate by gender, age and department of patients, and turnaround time of specimens.ResultsThe incidence rate of hemolysis, lipemia and icterus was 384, 53, and 612 per 10,000 specimens. The male patients had a significantly elevated incidence of hemolysis (4.13% vs. 3.54%), lipemia (0.67% vs. 0.38%), and icterus (6.95% vs. 5.43%) than female patients. Hemolysis, lipemia, and icterus incidence rate were significantly associated with the male sex with an odds ratio (OR) of 1.174 [95% confidence interval (CI), 1.140-1.208], 1.757 (95%CI: 1.623-1.903), and 1.303 (95%CI: 1.273-1.333), respectively, (P
... Importantly, COHb levels are a component of automated blood gas analysis, which is performed at least daily as part of routine neonatal intensive care [15]. Despite being readily available with potential clinical utility, COHb levels are currently not routinely considered in the clinical assessment and monitoring of disease progression in prematurely born infants. ...
Background
Carboxyhaemoglobin (COHb) levels may reflect the level of early oxidative stress which plays a role in mediating free-radical-related diseases in prematurely born infants.
Aim
To assess the relationship of COHb levels in the first seven days of after birth to the development of bronchopulmonary dysplasia (BPD) and other free-radical-related diseases.
Study design
Retrospective analysis of routinely performed COHb via blood gas samples of infants born at less than 30 weeks of gestation admitted to a tertiary neonatal intensive care unit was undertaken.
Subjects
One hundred and four infants were included with a median (range) gestational age of 27.4 (22.4–29.9) weeks and a birthweight of 865 (395–1710) grams.
Outcomes
The maximum COHb per infant per day was recorded for the first 28 days and BPD and other free-radical-related diseases including intraventricular haemorrhage (IVH) were noted. The severity of BPD, requirement for home oxygen on discharge and survival to discharge were also recorded.
Results
Infants who developed BPD (n = 76) had significantly higher COHb levels in the first seven days [1.7% (0.3–6.8)] compared to those that did not develop BPD [1.6% (0.9–3.8); p = 0.001]. Higher COHb levels in the first seven days after birth were also observed in infants with grade three/four IVH [n = 20; 1.9% (1.0–6.8)] compared to those without [1.6% (0.3–5.6); p < 0.001]. COHb levels, however, were not associated with the duration of ventilation, BPD severity or survival to discharge.
Conclusion
Higher COHb levels in prematurely born infants were associated with the development of BPD and IVH.
... While arterial blood gas (ABG) monitoring is the gold standard for blood gas analysis for measuring the partial pressure of oxygen (PaO 2 ) in arterial blood, it is an invasive and painful process. Hence it is not applicable for continuous monitoring [5], [6]. Pulse oximetry, a surrogate measurement method of arterial oxygen saturation (SaO 2 ) is a commonly used method to assess the blood oxygenation. ...
... Blood gas measurements and complementary, noninvasive monitoring techniques provide the clinician with information essential to patient assessment, therapeutic decision making, and prognostication. Blood gas measurements are as important for ill newborns as for other critically ill patients, but rapidly changing physiology, difficult access to arterial and mixed venous sampling sites, and small blood volumes present unique challenges [4]. ...
Objective: Both pulmonary and extra pulmonary causes could present as tachypnea and respiratory distress. We have planned a study to evaluate acid base status and outcome of neonatal respiratory distress. Methods: A prospective study carried on neonates admitted in intensive care unit from 1st November 2014 to 31st October 2015 in Department of Paediatrics of a tertiary care centre of UP. Ethical Clearance was taken by Ethics Committee of the college. Newborns brought to our NICU with respiratory distress were included in study randomly. After detailed clinical history, examination, arterial blood was taken in all the babies for ABG analysis with necessary precautions along with other routine investigation and stabilization of the baby. Results: A total of 115 neonates with respiratory distress were selected for study, out of these about 24.34% had normal pH, 45.21% had metabolic acidosis, 21.73% neonates had respiratory acidosis and 8.69% had mixed pH disorder. Neonates having respiratory distress with normal pH 85.71% were discharged from the hospital, 7.14% went LAMA and 7.14% expired during the treatment. Neonates having respiratory distress with abnormal pH 77.01% were discharged from the hospital, 2.29% went LAMA and 20.68% expired during the treatment. Conclusion: The expiry rate was significantly higher in neonates having abnormal pH with respiratory distress than in neonates with normal pH with respiratory distress (p<0.05).
... Preterm infants are vulnerable to alterations in arterial oxygen or carbon dioxide tension that can contribute to the development of main prematurity complications [24]. Blood gas monitoring is mandatory in respiratory monitoring, especially when invasive procedures are performed (mechanical ventilation, nitric oxide supplementation etc.) [25]. ...
... To determine interchangeability, a Bland-Altman analysis was performed, based on the 95% limits of agreement (LoA), estimated by mean difference (bias) ±2 SD of the differences, that provides a 95% confidence interval of the differences between VBG and CBG are expected to lie. Clinically acceptable difference for each blood gas value was defined up-front by means of an absolute difference: pH (±0.05), pCO2 (±0.66 kPa = 5 mmHg), pO2 (± 0.66 kPa = 5 mmHg), BE (±3 mmol/l/), and bicarbonate (±3 mmol/l), based on bias of reference values of infant's blood gas (11,20) and former studies (5,6,17). The oxygen saturation of our blood gasses are estimated values, not measured by cooximetry, and was not included in our analyses. ...
Background
Venous blood gas (VBG) is frequently used in the neonatal unit as alternative for capillary blood gas (CBG). However, studies reporting correlation are conflicting and data on interchangeability in neonates are lacking.Objective
We investigated the correlation and interchangeability of the components between VBG and CBG in infants admitted to the neonatal intensive care unit.Methods
In a prospective study in the neonatal unit in Leiden University Medical Center (Netherlands), simultaneously VBG and CBG were withdrawn in neonates when both venous puncture and intravenous access as blood gas monitoring was indicated. From each blood gas analysis, a Pearson correlation, intraclass correlation, and Bland–Altman analysis was performed. Clinically acceptable difference for each blood gas value was defined up-front by means of an absolute difference: pH ± 0.05; partial pressure of carbon dioxide (pCO2) (±0.67 kPa = 5 mmHg); partial pressure of oxygen (pO2) (±0.67 kPa = 5 mmHg); base excess ± 3 mmol/l; and bicarbonate (HCO3−) ± 3 mmol/l.ResultsIn 93 patients [median gestational age 31 (IQR 29–34) weeks], 193 paired samples of VBG and CBG were collected. The Pearson correlation between VBG and CBG was very strong for pH (r = 0.79; P < 0.001), BE (r = 0.90; P < 0.001) and bicarbonate (r = 0.87; P < 0.001); strong for pCO2 (r = 0.68; P < 0.001); and moderate for pO2 (r = 0.31; P < 0.001). The percentage of the interchangeability within our acceptable absolute difference for pH was 88%, pCO2 72%, pO2 55%, BE 90%, and bicarbonate 94%.ConclusionVBG and CBG in neonates are well correlated and mostly interchangeable, except for pO2.
... Most interestingly, the analyses of blood gases before and after transfers demonstrated significant improvements in blood pH and base deficit, while partial pressure of carbon dioxide remained unchanged. Since base deficit reflects the patient's total metabolic and circulatory status (13,14), the observed improvement might indicate that most patients' requirements were met during transport. This is reassuring given both the composition of the highly vulnerable study population and the fact that the median stabilisation time was significantly shorter than previously reported (15). ...
Aim:
This study evaluated the medical quality of acute airborne transports carried out by a neonatal emergency transport service in a Swedish healthcare region from 2012-2015.
Methods:
The transport charts and patient records of all infants transported to the regional centre were reviewed for transport indications and vital parameters and outcomes.
Results:
We identified 187 acute airborne transports and the main indications for referral were therapeutic hypothermia after perinatal asphyxia, extremely preterm birth and respiratory failure. There were 37 deaths, but none of these occurred during transport and none of the deaths that occurred within 24 hours after transport were found to be related to the transport per se. No differences were found in vital parameters or ventilator settings before and after transport, except for an improvement in blood pH (7.22 ±0.13 versus 7.27 ±0.13, mean ± SD, p<0.01), due to a decrease in base deficit (-8.0 ±6.8 versus -5.4 ±6.3 mmol, p<0.001), while the partial pressure of carbon dioxide remained unchanged.
Conclusion:
During air transport, critically ill neonates displayed stable vital parameters and reduced metabolic acidosis. No transport-related mortality was found, but the high number of extremely preterm infants transported indicates the potential for improving in-utero transport. This article is protected by copyright. All rights reserved.
... Primary outcomes 1 Acidosis (defined by the study); typically using the biochemical markers of pH, base excess, pO 2 , and pCO 2 , or the proxy marker of low Apgar scores 41 ...
( BJOG 2017;124:584–594)
Testing for acidosis at all deliveries is advocated by some as an early and effective way to identify infants at risk for a range of adverse neonatal outcomes. A low umbilical artery potential of hydrogen (pH) has been associated with poor outcomes such as cerebral palsy, encephalopathy, and death. While acidosis is not the direct cause of these negative outcomes and most acidotic newborns suffer no adverse effects, knowledge of the presence of the acidosis may allow clinicians to alter their treatment in an attempt to improve outcomes.
... Primary outcomes 1 Acidosis (defined by the study); typically using the biochemical markers of pH, base excess, pO 2 , and pCO 2 , or the proxy marker of low Apgar scores 41 ...
Background:
Umbilical cord lactate is one approach to measuring acidosis and intrapartum hypoxia, knowledge of which may be helpful for clinicians involved in the care of women and newborns.
Objective:
To synthesise the evidence on accuracy of umbilical cord lactate in measuring acidosis and predicting poor neonatal outcome.
Search strategy:
Studies published and unpublished between 1990 and 2014 from PubMed/Medline, EMBASE, Cochrane Central Register of Controlled Trials, and clinicaltrials.gov were assessed.
Selection criteria:
Cross-sectional and randomised studies that assessed fetal acidosis (using lactate as the index test) with or without an assessment of neonatal outcome.
Data collection and analysis:
Correlations between index and reference test(s) were recorded, as were the raw data to classify the predictive ability of umbilical lactate for neonatal outcomes. Meta-analysis of correlation was performed. We plotted estimates of the studies' observed sensitivities and specificities on Forest plots with 95% confidence intervals (CI). Where possible, we combined data using meta-analysis, applying the hierarchical summary receiver operating characteristics model and a bivariate model.
Main results:
Twelve studies were included. Umbilical lactate correlated with pH [pooled effect size (ES) -0.650; 95% CI -0.663 to -0.637, P < 0.001], base excess (ES -0.710; 95% CI -0.721 to -0.699, P < 0.001), and Apgar scores at 5 minutes (ES 0.300; 95% 0.193-0.407, P < 0.001). Umbilical lactate had pooled sensitivity and specificity for predicting neonatal neurological outcome including hypoxic ischaemic encephalopathy of 69.7% (95% CI 23.8-94.4%) and 93% (95% CI 86.8-96.3%).
Authors' conclusion:
Umbilical cord lactate is a clinically applicable, inexpensive and effective way to measure acidosis and is a tool that may be used in the assessment of neonatal outcome.
Tweetable abstract:
Umbilical cord lactate: a clinically applicable, inexpensive, effective way to measure intrapartum acidosis.
... Restricted transfusion guideline is the unit's protocol [14]. The cut-off taken for hypoxia, hyperoxia, hypocarbia, and hypercarbia was 50, 100, 25, and 60 mmHg, respectively [15][16][17]. ...
Background: Definition of neonatal hypoglycemia is still controversial.
Objective: To find the effect of blood glucose (BG) levels in the first 3 days of life, on developmental outcome at 1 year in low birth weight neonates <2000 g.
Methods: A prospective cohort study was conducted in tertiary level neonatal intensive care unit and follow-up clinic in south India. Intramural neonates admitted from September 2009 to August 2010 were enrolled. Perinatal and neonatal variables were recorded. Respiratory support, fluids, and feeding management were based on the standard protocols. BG was measured within 2 h, then 6 hourly for 72 h by glucometer and BG <50 mg% was analyzed by hexokinase method. Infants were followed until 1 year corrected age and development age (DA) assessed by Developmental Assessment Scales for Indian Infants (DASII). Motor and mental DA at various BG levels were compared. Composite outcome of motor or mental developmental delay; or cerebral palsy or hearing impairment or visual impairment was analyzed, and logistic regression analysis was performed.
Results: The mean birth weight and gestation of the study group (n=129) was 1493 g and 32.5 weeks. The 10th centile of BG in the first 72 h was 51 mg%. BG below 10th centile was seen in 60 infants. The mean motor and mental DA of the infants by DASII assessment at 1 year was 11.3 and 11.5 months, respectively. The motor DA and mental DA were significantly higher until 50 mg% lowest BG level, and positive correlation was seen (r=0.26 motor, 0.2 mental DA). Mean BG level, the presence of symptoms; number of episodes or small for gestation did not influence the DA. The adjusted odds for poor composite outcome when BG was below 51 mg% is 2.83 (0.65-12.3).
Conclusion: Even though high-risk neonates with BG <51 mg% have a lower motor DA and mental DA at 1 year, than neonates with BG >50 mg%; other morbidities do determine their composite outcome.
... a) b) 01-2016/v.1. Nacionalne preporuke za kapilarno uzorkovanje krvi rezultate plinova u krvi (39,40), pa može lažno povećati ili smanjiti parcijalni tlak kisika (pO 2 ) u krvi i posljedično zasićenost krvi kisikom (3,41). Također, moguće su i promjene koncentracije glukoze i laktata (42). ...
Uzorkovanje kapilarne krvi je sve zastupljeniji medicinski postupak čiji rezultati sudjeluju u donošenju medicinskih odluka (postavljanje radne dijagnoze, odluke o daljnjim dijagnostičkim i terapijskim postupcima). Često se koristi zbog dobivanja malih volumena krvi potrebnih za laboratorijske pretrage, ali i zbog jednostavnijeg i manje invazivnog postupka od venskog uzorkovanja. Sve veća prisutnost dijagnostike uz bolesnika (engl. point-of care testing, POCT) dodatni je razlog sve učestalijem korištenju kapilarnog uzorka u svakodnevnoj, modernoj medicini.
Način uzorkovanja kapilarne krvi može utjecati na kvalitetu uzorka, a time i na rezultate pretraga što naglašava potrebu za standardizacijom postupka. Nedavno anketno ispitivanje postupka kapilarnog uzorkovanja u medicinsko-biokemijskim laboratorijima Republike Hrvatske, pokazalo je da on nije standardiziran te da mali broj laboratorija ovaj postupak provodi u skladu sa dostupnim međunarodnim smjenicama. (engl. Clinical Laboratory Standards Institute, CLSI i/ili smjernice Svjetske zdravstvene organizacije (engl. World Health Organization, WHO).
Cilj ovog dokumenta je izrada preporuke za uzorkovanje kapilarne krvi na nacionalnoj razini od strane Radne grupe za kapilarno uzorkovanje Povjerenstva za znanstveno-stručni razvoj Hrvatskog društva za medicinsku biokemiju i laboratorijsku medicinu. Naše preporuke se temelje na postojećim, dostupnim međunarodnim standardima i preporukama uz prilagodbu prema logističkim, kulturalnim, zakonskim i regulatornim potrebama na nacionalnoj razini. Nadamo se da će ove preporuke biti koristan doprinos standardizaciji uzorkovanja kapilarne krvi u Hrvatskoj.
Ključne riječi: preporuke; kapilarna krv; uzorkovanje krvi; standardizacija
... Hypoxia resulting from a diminished blood flow secondary to enhanced uterine contractions, as may occur at high doses of oxytocin or when oxytocin is administered early during parturition or during dystocia, can be prevented by administering oxytocin at low doses and at advanced stages of parturition, as was observed in the biochemical evaluations, including electrolyte and blood gases levels, performed in the present studies. Prolonged hypoxia during parturition could lead to the development of acidosis (21,26), even if compensating mechanisms are present (25). ...
... Many articles have been written on the fundamental concepts and interpretation of ABG [27][28][29][30][31][32][33][34][35][36][37][38] . ...
Arterial blood gases (ABG) results reflect underlying pathology and interpretation of the results are often compounded by ongoing disease processes and clinical interventions. While ABG specimens should be analysed immediately for optimal results the Clinical and Laboratory Standards Institute (CLSI) has recommended a window of 30 minutes at room temperature from blood collection to ABG analysis. A fresh and simple approach to interpreting ABG is provided.
... Hypoxia resulting from a diminished blood flow secondary to enhanced uterine contractions, as may occur at high doses of oxytocin or when oxytocin is administered early during parturition or during dystocia, can be prevented by administering oxytocin at low doses and at advanced stages of parturition, as was observed in the biochemical evaluations, including electrolyte and blood gases levels, performed in the present studies. Prolonged hypoxia during parturition could lead to the development of acidosis (21,26), even if compensating mechanisms are present (25). ...
... For example, excessive crying by babies can alter blood gas tests (39,40), leading to under-or overestimates of pO 2 and of oxygen saturation calculated from pO 2 (3,41), as well as to overestimates of glucose and lactate concentrations (42). Therefore such an event must be recorded on the laboratory test report (3) with a note, such as "Excessive crying during capillary blood sampling. ...
Capillary blood sampling is a medical procedure aimed at assisting in patient diagnosis, management and treatment, and is increasingly used worldwide, in part because of the increasing availability of point-of-care testing. It is also frequently used to obtain small blood volumes for laboratory testing because it minimizes pain. The capillary blood sampling procedure can influence the quality of the sample as well as the accuracy of test results, highlighting the need for immediate, widespread standardization. A recent nationwide survey of policies and practices related to capillary blood sampling in medical laboratories in Croatia has shown that capillary sampling procedures are not standardized and that only a small proportion of Croatian laboratories comply with guidelines from the Clinical Laboratory Standards Institute (CLSI) or the World Health Organization (WHO).
The aim of this document is to provide recommendations for capillary blood sampling. This document has been produced by the Working Group for Capillary Blood Sampling within the Croatian Society of Medical Biochemistry and Laboratory Medicine. Our recommendations are based on existing available standards and recommendations (WHO Best Practices in Phlebotomy, CLSI GP42-A6 and CLSI C46-A2), which have been modified based on local logistical, cultural, legal and regulatory requirements. We hope that these recommendations will be a useful contribution to the standardization of capillary blood sampling in Croatia.
... Strict management of oxygen therapy to minimize episodes of hyperoxia and hypoxia was associated with decreased incidences of retinopathy of prematurity (ROP) over a period of 5 years 15 .In special conditions like preterm VLBW, chronic lung disease (CLD), bronchopulmonary dysplasia (BPD) oxygen therapy should be individulaised 5,12,15,16 . Generally SpO 2 is maintained at 85% -95% (85% -92% if <29 weeks gestation) range 17 . ...
When supplementation of oxygen is inappropriate there is chance of development of either hypoxia or hyperoxia. During oxygen therapy, oxygen level should be maintained within a target-able range through proper monitoring. Pulse oximetry is a useful convenient and reliable monitoring system. The principle of working of pulse oximeter is based on the fact that oxyhaemoglobin and deoxyhaemoglobin absorb light at the red end of the spectrum differently; Deoxyhaemoglobin absorbs more red than infrared and oxyhaemoglobin more infrared than red. The 'emitter' of the probe of pulse oximeter sends equal intensities of red and infrared light into the tissue. The 'sensor' detects the ratio of red to infrared that emerges. From this information the proportion of oxyhaemoglobin to deoxyhaemoglobin-that is, the percentage saturation of hemoglobin with oxygen is calculated and displayed to the monitor of the instrument. The main advantage of pulse oximeter is that it is non-invasive, less complex, does not require calibration, provides continuous measurement of hemoglobin-oxygen saturation (SpO 2), fast response time and high accuracy. Limitations of accuracy of pulse oximetry lie on poor perfusion, hypoxic events, hyperemia, severe anemia, dyshemoglobinemias, high oxygen partial pressures (P a O 2), superficial pigments, black skin of infant, motion artifact, pressure on sensor, presence of abnormal dye, light and electrical interference. It is essential to remember the limitations of this instrument before going to pulse oximetry.
... Methods of neonatal blood gas measurement include: 1 • indwelling arterial catheters, e.g. umbilical or peripheral arterial line (which also allow invasive blood pressure monitoring) • peripheral arterial 'stab' puncture sample • capillary blood sample (commonly taken from a heelstick) • non-invasive methods: oxygen saturation monitoring, end-tidal carbon dioxide (CO 2 ) monitoring and transcutaneous oxygen tension /CO 2 monitoring. ...
Blood gas sampling is part of everyday practice in the care of babies admitted to the neonatal intensive care unit, particularly for those receiving respiratory support. There is little published guidance that systematically evaluates the different methods of neonatal blood gas sampling, where each method has its individual benefits and risks. This review critically surveys the available evidence to generate a comparison between arterial and capillary blood gas sampling, focusing on their relative accuracy and complications, as well as briefly mentioning the management of such complications. This evidence-based summary and guidance should help inform best practice in the neonatal intensive care unit, and minimise the exposure of babies to unnecessary and potentially serious risk. The most accurate and non-invasive method of measuring oxygenation is oxygen saturation monitoring. Indwelling arterial catheters are a practical, reliable and accurate method of measuring acid-base parameters, provided they are inserted and maintained with the proper care. Capillary blood gas sampling is accurate, and a good substitute for radial 'stab' arterial puncture, avoiding many of the complications of repeated arterial puncture.
... Birth heralds in a sudden increase in arterial partial pressure of oxygen (PaO 2 ) from ~25-30 Torr in utero to ~60 Torr at atmosphere (Brouillette and Waxman, 1997). This necessitates a transient suppression of the peripheral chemoreceptor organs, the carotid bodies (Mortola, 2001). ...
Respiratory control entails coordinated activities of peripheral chemoreceptors (mainly the carotid bodies) and central chemosensors within the brain stem respiratory network. Candidates for central chemoreceptors include Phox2b-containing neurons of the retrotrapezoid nucleus, serotonergic neurons of the medullary raphé, and/or multiple sites within the brain stem. Extensive interconnections among respiratory-related nuclei enable central chemosensitive relay. Both peripheral and central respiratory centers are not mature at birth, but undergo considerable development during the first two postnatal weeks in rats. A critical period of respiratory development (∼P12-P13 in the rat) exists when abrupt neurochemical, metabolic, ventilatory, and electrophysiological changes occur. Environmental perturbations, including hypoxia, intermittent hypoxia, hypercapnia, and hyperoxia alter the development of the respiratory system. Carotid body denervation during the first two postnatal weeks in the rat profoundly affects the development and functions of central respiratory-related nuclei. Such denervation delays and prolongs the critical period, but does not eliminate it, suggesting that the critical period may be intrinsically and genetically determined.
... Fetal arterial PO 2 in mammals is about 23-28 mmHg and rises~4 fold within the first two hours after birth [27,28], raising the additional possibility that oxygendependent gene expression may change during the first days or weeks after birth [29,30]. Specifically, oxygen tension may affect the expression of reference genes in a tissue-specific manner [13,31], suggesting that candidate reference genes for normalization should be validated not only for a given tissue but also for oxygen conditions that may affect expression and over the time frame when such changes may occur. ...
ABSTRACT:
The carotid bodies are the main arterial oxygen chemoreceptors in mammals. Afferent neural output from the carotid bodies to brainstem respiratory and cardiovascular nuclei provides tonic input and mediates important protective responses to acute and chronic hypoxia. It is widely accepted that the selection of reference genes for mRNA normalization in quantitative real-time PCR must be validated for a given tissue and set of conditions. This is particularly important for studies in carotid body during early postnatal maturation as the arterial oxygen tension undergoes major changes from fetal to postnatal life, which may affect reference gene expression. In order to determine the most stable and suitable reference genes for the study of rat carotid body during development, six commonly used reference genes, β-actin, RPII (RNA polymerase II), PPIA (peptidyl-proyl-isomerase A), TBP (TATA-box binding protein), GAPDH, and 18s rRNA, were evaluated in two age groups (P0-1 and P14-16) under three environmental oxygen conditions (normoxia, chronic hypoxia and chronic hyperoxia) using the three most commonly used software programs, geNorm, NormFinder and BestKeeper.
The three programs produced similar results but the reference gene rankings were not identical between programs or experimental conditions. Overall, 18s rRNA was the least stable reference gene for carotid body and, when hyperoxia and/or hypoxia conditions were included, actin was similarly unstable.
Reference or housekeeping gene expression for qPCR studies of carotid body during postnatal development may vary with developmental stage and environmental conditions. Selection of the best reference gene or combination of reference genes for carotid body development studies should take environmental conditions into account. Two commonly used reference genes, 18s rRNA and actin, may be unsuitable for studies of carotid body maturation, especially if the study design includes altered oxygen conditions.
... [1][2][3][4][5] Pulse oximetry provides physicians with a noninvasive and accurate method to evaluate oxygenation for neonates in various clinical situations. [6][7][8][9] However, the reliable and accurate noninvasive assessment of arterial partial pressure of carbon dioxide (PaCO 2 ) in neonates, especially premature infants, remains equivocal because of technical limitations. [1][2][3]10,11 End-tidal CO 2 (PetCO 2 ) monitoring by capnography is a continuous and noninvasive measurement to monitor blood CO 2 tension. ...
Arterial blood gas analysis is the gold standard for assessing the adequacy of ventilation. However, arterial blood sampling may be associated with serious complications in neonates. The aim of the study was to utilize the side-stream capnometry measurement of end-tidal carbon dioxide (PetCO₂) via nasal cannula circuits and to verify the reliability of PetCO₂ in reflecting the arterial blood carbon dioxide(PaCO₂) level in nonintubated neonates.
A retrospective medical record review analysis was performed in nonintubated neonates admitted to the neonatal ward in a medical center. Simultaneous arterial PaCO₂ and PetCO₂ levels were evaluated. PaCO₂ and PetCO₂ levels were compared by paired t test and were correlated using Pearson's correlation. The PetCO₂ bias was defined as the difference between PaCO₂ and PetCO₂, and was assessed by Bland-Altman plot analysis.
A total of 34 neonates were recruited, and data of 54 pairs of PaCO₂ and PetCO₂ levels were available for comparison. The average (mean ± SD) gestational age was 32.5 ± 4.2 weeks, and the average birth weight was 1881 ± 1077 g. There was a good correlation between PetCO₂ and PaCO₂ levels among all paired samples (r = 0.809, p < 0.001). When the data were divided into those with respiratory disease (n = 34) and those without (n = 20), significant correlation between PetCO₂ and PaCO₂ levels were both noted in the former group (r = 0.823, p < 0.001) and the latter group (r = 0.770, p < 0.001). The overall average mean value of PetCO₂ was lower than that of PaCO₂ (39.4 ± 8.8 mmHg vs. 41.3 ± 9.2 mmHg, p = 0.014). The difference between PetCO₂ and PaCO₂ levels was significant only among those with respiratory disease (38.8 ± 9.8 mmHg vs. 41.2 ± 10.3 mmHg, p = 0.027), but not among those without (40.5 ± 7.0 mmHg vs. 41.6 ± 7.2 mmHg, p = 0.289).
End-tidal CO₂ measurement by side-stream capnometry through nasal cannula could provide an accurate and noninvasive estimate of PaCO₂ levels in nonintubated neonates.
... Such co-assembly is likely to increase the afferents (Finley and Katz, 1992). During the first two postnatal days, a sudden increase in arterial partial pressure of oxygen (Brouillette and Waxman, 1997) transiently suppresses peripheral chemosensitive organs (primarily the carotid bodies), which reset thereafter (Blanco et al., 1984; Mortola, 2001). We have shown previously that the ventilation and metabolic patterns of P0-1 rats were markedly different from those of P2 and older rats, both during normoxia and under hypoxia (Liu et al., 2009), with the lowest response to hypoxia at P3 among P0-P11 rats () and almost the lowest metabolic rate response to hypoxia at the same time (Liu et al., 2009). ...
Previously, we reported that a critical period in respiratory network development exists in rats around postnatal days (P; P12-P13), when abrupt neurochemical, metabolic, and physiological changes occur. Specifically, the expressions of glutamate and N-methyl-d-aspartate (NMDA) receptor (NR) subunit 1 in the pre-Bötzinger complex (PBC), nucleus ambiguus (Amb), hypoglossal nucleus (XII), and ventrolateral subnucleus of solitary tract nucleus (NTS(VL)) were significantly reduced at P12. To test our hypothesis that other NR subunits also undergo postnatal changes, we undertook an in-depth immunohistochemical study of NR2A, 2B, 2C, 2D, and 3B in these four respiratory nuclei in P2-P21 rats, using the non-respiratory cuneate nucleus (CN) as a control. Our results revealed that: (1) NR2A expression increased gradually from P2 to P11, but fell significantly at P12 in all four respiratory nuclei (but not in the CN), followed by a quick rise and a relative plateau until P21; (2) NR2B expression remained relatively constant from P2 to P21 in all five nuclei examined; (3) NR2C expression had an initial rise from P2 to P3, but remained relatively constant thereafter until P21, except for a significant fall at P12 in the PBC; (4) NR2D expression fell significantly from P2 to P3, then plateaued until P12, and declined again until P21; and (5) in contrast to NR2D, NR3B expression rose gradually from P2 to P21. These patterns reflect a dynamic remodeling of NMDA receptor subunit composition during postnatal development, with a distinct reduction of NR2A expression during the critical period (P12), just as NR1 did in various respiratory nuclei. There was also a potential switch between the neonatal NR2D and the more mature NR3B subunit, possibly around the critical period. Thus, during the critical period, NMDA receptors are undergoing greater adjustments that may contribute to attenuated excitatory synaptic transmission in the respiratory network.
... Hypoxia resulting from a diminished blood flow secondary to enhanced uterine contractions, as may occur at high doses of oxytocin or when oxytocin is administered early during parturition or during dystocia, can be prevented by administering oxytocin at low doses and at advanced stages of parturition, as was observed in the biochemical evaluations, including electrolyte and blood gases levels, performed in the present studies. Prolonged hypoxia during parturition could lead to the development of acidosis (21,26), even if compensating mechanisms are present (25). ...
Sixty hybrid Yorkshire-Landrace penned sows, 30 with eutocic farrowing and 30 experiencing a dystocic parturition, were studied to evaluate the obstetric and neonatal outcomes to low doses of oxytocin administered at advanced stages of parturition. Animals in each group were randomly subdivided into 2 subgroups: 15 eutocic and 15 dystocic sows received oxytocin 0.083 IU/kg (equivalent to 1 IU/12 kg body weight), administered intramuscularly after the delivery of the 5th piglet; the other 15 eutocic and 15 dystocic sows received saline solution intramuscularly at the same time. Oxytocin decreased the number of intrapartum deaths by approximately 50% (P = 0.002). No piglet was born dead from the saline- and oxytocin-treated eutocic sows. The highest viability score was observed among piglets born to eutocic sows treated with oxytocin. In summary, this dose schedule would help to decrease the number of stillbirths in both eutocic and dystocic farrowing sows.
: Background: The term “bacterial translocation” (BT) refers to the migration of bacteria or their products from the gastrointestinal tract to tissues located outside it, and may occur after intestinal ischemia-reperfusion injury. The term “endotoxin” is synonymous, and is used interchangeably with the term lipopolysaccharide (LPS). LPS, a component of Gram-negative gut bacteria, is a potent microbial virulence factor, that can trigger production of pro-inflammatory mediators, causing
localized and systemic inflammation. The aim of this study is to investigate if neonatal asphyxia provokes BT and an increased concentration of LPS in an animal model of asphyxia in piglets.
Methods: Twenty-one (21) newborn male Landrace/Large White piglets, 1–4 days old, were randomly allocated into three groups, Control (A), Asphyxia (B) and asphyxia-Cardiopulmonary Resuscitation (CPR) (C). All animals were instrumented, anesthetized and underwent hemodynamic monitoring.
In Group A, the animals were euthanized. In Group B, the endotracheal tube was occluded to cause asphyxia leading to cardiopulmonary arrest. In Group C, the animals were resuscitated after asphyxia and further monitored for 300
. Bacterial translocation was assessed by the measurement of endotoxin
in blood from the portal vein and the aorta, and also by the measurement of endotoxin in mesenteric lymph nodes (MLNs) at euthanasia. The results are given as median (IQR) with LPS concentration in EU/mL. Results: BT was observed in all groups with minimum LPS concentration in the MLN and maximum concentration in the portal vein. LPS levels in the MLNs were higher in the Group B: 6.38 EU/mL (2.69–9.34) compared to the other groups (Group A: 2.1 EU/mL (1.08–2.52), Group
C: 1.66 EU/mL (1.51–2.48), p = 0.012). The aorta to MLNs LPS difference (%) was lower in Group B: 0.13% (0.04–1.17), compared to Group A: 5.08% (2.2–10.7), and Group C: 3.42% (1.5–5.1)) (p = 0.042).
The same was detected for portal to MLNs LPS difference (%) which was lower in Group B: 0.94% (0.5–3) compared to Group A: 4.9% (4–15), and Group C: 3.85% (1.5–5.1)) (p = 0.044).
Conclusions: Neonatal asphyxia can provoke BT and increased LPS concentration in blood and tissue located outside the gastrointestinal system.
Background:
Pre-discharge capillary blood gas partial pressure of carbon dioxide (pCO2) has been associated with increased adverse events including readmission. This study aimed to determine if pre-discharge pCO2 or 36-week pCO2 was associated with increased respiratory readmissions or other pulmonary healthcare utilization in the year after NICU discharge for infants with BPD discharged with home oxygen, using a standardized outpatient oxygen weaning protocol.
Methods:
This was a secondary cohort analysis of infants born <32 weeks gestational age with BPD, referred to our clinic for home oxygen therapy from either from our level IV NICU or local level III NICUs between 2015-17. Infants with major non-respiratory comorbidities were excluded. Subject information was obtained from electronic health records.
Results:
Of 125 infants, 120 had complete 1-year follow-up. Twenty three percent of infants experienced a respiratory readmission after NICU discharge. There was no significant association between pre-discharge or 36-week pCO2 and respiratory readmissions, emergency room visits, new or increased bronchodilators or diuretics. Higher 36-week pCO2 was associated with a later corrected age when oxygen was discontinued (<6 months, median 54 mm Hg, Interquartile range (IQR) 51-61; 6-11 months, median 62 mm Hg IQR 57-65; ≥12 months, median 66 mm Hg, IQR 58-73; p=0.006).
Conclusions:
Neither pre-discharge pCO2 nor 36-week pCO2 was associated with one-year respiratory readmissions. However higher pCO2 at 36 weeks was associated with longer duration of home oxygen. Neonatal illness measures like 36-week pCO2 may be useful in communicating expectations for home oxygen therapy to families. This article is protected by copyright. All rights reserved.
Background
Reference intervals for arterial and venous umbilical cord blood gas (UCBG) parameters are scarce, are mainly focused on pH, pO2, pCO2 and base deficit, and are usually assessed using parametric tests, despite a generally skewed data distribution. Here, the purpose is to determine reference percentiles for nine parameters of concomitant arterial and venous UCBG (CAV-UCBG) from neonates at birth, using nonparametric tests.
Methods
Results of CAV-UCBG, assayed over a 4.5-year period, were extracted from a hospital laboratory database for pH, pCO2, pO2, oxygen saturation, concentration of total oxygen, total carbon dioxide, hydrogen carbonate, total haemoglobin, and acid-base excess. Exclusion criteria were: a venous–arterial pH difference <0.02, an arterial–venous pCO2 <0.7 kPa, and a venous pCO2 <2.9 kPa. Nonparametric bivariate kernel density estimations were used for the selection of plots within the 95% percentile surface of the pCO2-to-pH relationship (NBKDE-95P). Outliers from skewed data were removed using an adjusted-Tukey method, and percentiles were calculated according to the CLSI EP28-A3 nonparametric method.
Results
Overall, 31% (5033/16164) of CAV-UCBG were discarded using the three exclusion criteria. Then, 6% (670/11131) of CAV-UCBG were excluded from the NBKDE-95P, and 0.1 to 3.5% outliers were subsequently removed. Depending on the parameter, the 2.5th and 97.5th percentiles from the whole group were similar or slightly narrower compared to reference intervals from other studies, while those from female and male neonates did not differ substantially.
Conclusions
Using an indirect nonparametric approach, this study proposes new percentiles for parameters from concomitant arterial and venous umbilical cord blood gases.
Aim:
We investigated the association between active hypothermia and hypocapnia in neonates with moderate to severe hypoxic-ischaemic encephalopathy (HIE) transported after birth.
Methods:
This was a retrospective cohort study of neonates with HIE born between 2007-2011 and transported to Semmelweis University, Hungary, for hypothermia treatment before and after we introduced active cooling during transport in 2009. Of these, 71 received intensive care plus controlled active hypothermia during transport, while the 46 controls just received standard intensive care. Incident hypocapnia was defined as a partial pressure of carbon-dioxide (pCO2 ) that decreased below 35 mmHg during transport. Multivariable logistic regression investigated the relationship between hypothermia and incident hypocapnia.
Results:
Incident hypocapnia was more frequent in the actively cooled transport group (36.6%) than control group (17.4%; p=0.025). PCO2 decreased from a median of 45 to 35 mmHg (p<0.0001) in the intervention group, but remained unchanged in the controls. After adjusting for confounders, hypothermia remained an independent risk factor for hypocapnia with an odds ratio (OR) of 4.23 and 95% confidence interval (95% CI) of 1.30-13.79. Sedation was associated with a reduction in OR of hypocapnia, at 0.35 (95% CI 0.12-0.98).
Conclusions:
Hypothermia increased the risk of hypocapnia in neonates with HIE during transport. This article is protected by copyright. All rights reserved.
This is the protocol for a review and there is no abstract. The objectives are as follows:
• To assess whether the use of continuous tcPCO2 monitoring versus any intermittent modalities to measure CO2 (e.g. blood gas determinations, end tidal CO2 or tcPCO2 monitoring itself) in newborn infants reduces mortality and improves short and long term respiratory and neurodevelopmental outcomes;
• To assess whether the use of continuous tcPCO2 monitoring versus other continuous CO2 monitoring (i.e. continuous end tidal CO2) in newborn infants reduces mortality and improves short and long term respiratory and neurodevelopmental outcomes;
• To assess whether the use of continuous tcPCO2 associated with intermittent CO2 monitoring (such as blood gas determinations or end tidal CO2) versus continuous tcPCO2 without intermittent CO2 monitoring in newborn infants reduces mortality and improves short and long term respiratory and neurodevelopmental outcomes.
Background:
Carbon dioxide (CO2) measurement is a fundamental evaluation in a neonatal intensive care unit (NICU), as both low and high values of CO2 might have detrimental effects on neonatal morbidity and mortality. Though measurement of CO2 in the arterial blood gas is the most accurate way to assess the amount of CO2, it requires blood sampling and it does not provide a continuous monitoring of CO2.
Objectives:
To assess whether the use of continuous transcutaneous CO2 (tcCO2) monitoring in newborn infants reduces mortality and improves short and long term respiratory and neurodevelopmental outcomes.
Search methods:
We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 11), MEDLINE via PubMed (1966 to November 1, 2015), EMBASE (1980 to November 1, 2015), and CINAHL (1982 to November 1, 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.
Selection criteria:
Randomized, quasi-randomized and cluster randomized controlled trials comparing different strategies regarding tcCO2 monitoring in newborns. Three comparisons were considered, that is, continuous tcCO2 monitoring versus 1) any intermittent modalities to measure CO2; 2) other continuous CO2 monitoring; and 3) with or without intermittent CO2 monitoring.
Data collection and analysis:
We used the standard methods of the Cochrane Neonatal Review Group. Two review authors independently assessed studies identified by the search strategy for inclusion.
Main results:
Our search strategy yielded 106 references. Two review authors independently assessed all references for inclusion. We did not find any completed studies for inclusion, nor ongoing trials.
Authors' conclusions:
There was no evidence to recommend or refute the use of transcutaneous CO2 monitoring in neonates. Well-designed, adequately powered randomized controlled studies are necessary to address efficacy and safety of transcutaneous CO2 monitoring in neonates.
Clinical chemistry is a broad field spanning biochemistry, medicine, and technology. Its application for pediatric patients, and newborns and infants in particular, distinguishes pediatric clinical chemistry as a 'field within a field' containing may unique characteristics. Among these is the need to recognize that blood collection from a small infant and work with small specimen volumes requires specific procedures different from those used for adults. Physiologic changes that occur during growth of an infant are reflected in changes in many analytes over time, requiring that appropriate age-related reference ranges be used to evaluate laboratory results. This article attempts to review some of the unique characteristics of pediatric clinical chemistry.
The role of the anesthesiologist is to modify consciousness, pain perception, and memory as well as to protect organ function during surgical procedures and critical illness. In order to fulfill this role, we gather information from bedside patient monitors and use this information to make clinical decisions. Monitoring the neonate poses special challenges because of the rapid physiological changes in the first few days of life, poorly defined measures of consciousness, and the physical limitations of small size relative to the size of the monitoring devices. The circumstances that bring a neonate for a surgical procedure involve life- or major organ system-threatening conditions. As a consequence, protection of organ function becomes a major focus
La duración y grado de asfixia perinatal en el humano influye en la morbilidad fetal y neonatal así como su mortalidad (James et al., 1958). Nelson et al. (1996); (citados por Brouillette y Waxman, 1997), reportan que 10 a 20% de los casos de parálisis cerebral en niños, son consecuencia de la asfixia perinatal. La hipoxia, hipercarbia (acidosis respiratoria) y acidosis metabólica (frecuentemente medida por el déficit de base) secundarios al metabolismo anaeróbico, son características esenciales de la asfixia. La evaluación de dichos parámetros a partir de sangre arterial de cordón umbilical al nacimiento, tanto de recién nacidos (RN) humanos como en animales, ha permitido evaluar la gravedad de la asfixia intraparto (James et al., 1958) y ha sido correlacionada con indicadores fetales, tales como; patrones de la frecuencia cardiaca fetal, determinación de gases sanguíneos del cuero cabelludo y la Valoración de Apgar (Strickland et al., 1984). La sangre obtenida del cordón umbilical en neonatos humanos, proporciona información suficiente para estimar el estado de los fetos al nacimiento y la relación con el déficit de base, cambios en las concentraciones de presión de oxígeno (pO 2), saturación de O 2 , SO 2 , presión de bióxido de carbono (pCO 2) y pH debido al intercambio continuo de gases sanguíneos en la placenta después de la oclusión del cordón (Nodwell et al., 2005). Además de esto, los gases en sangre proporcionan información importante sobre el estado del paciente después del nacimiento (Brouillette y Waxman, 1997) y pueden ayudar tanto a clínicos e investigadores en la evaluación y tratamiento antes y posterior al nacimiento así como en el cuidado postnatal del neonato (Strickland et al., 1984). Sin embargo, el muestreo sanguíneo de cordón umbilical algunas veces es limitado debido a la dificultad para obtener un volumen suficiente de sangre al nacimiento (Nodwell et al., 2005). Los eventos que acontecen en un proceso de asfixia aguda, tales como acidosis metabólica e hipoxia comunes en cerdos, interactúan con el bienestar del lechón y su desempeño postnatal, prolongando el tiempo que tarda para conectar la teta y el inicio de la primer mamada, originando un menor consumo de calostro, un inadecuado estado inmune y una disminución de la temperatura corporal, con su consiguiente disminución de viabilidad. Son necesarios más estudios para monitorear el estrés fetal durante el parto, a través del desequilibrio ácido base y el metabolismo energético, ambas herramientas parecen ser buenas opciones en obstetricia porcina. Por otro lado, aparentemente varios de los factores que causan la asfixia también podrían ser el efecto, por ejemplo, el meconio; la asfixia causa relajación que estimula la respiración del feto in útero, y por otro lado, la anoxia aumenta la peristalsis intestinal, ocasionando que el feto defeque meconio en el líquido amniótico. Así mismo, deben realizarse estudios de correlación entre los diversos métodos para cuantificar el vigor de un neonato: la latencia a primer amamantamiento, la valoración del pulso cardiaco, el ritmo respiratorio, el tono muscular y otros parámetros, debido a que además de la hipoxia, las causas de disminución del vigor del lechón se pueden deber a otros factores, entre ellos los genéticos, endocrinos, el peso al nacimiento y el ambiente durante el parto. Importancia de la gasometría en perinatología En perinatología humana la medición de gases en sangre (pO 2 , pCO 2 y pH), además de técnicas complementarias a través del monitoreo no invasivo, proporcionan información esencial para evaluar al paciente, tomar la decisión terapéutica y realizar un diagnóstico correcto (Nodwell et al., 2005). Aunado a esto, los valores de mediciones de gases sanguíneos de arteria umbilical sirven también para identificar a los neonatos que necesitan cuidado neonatal extra, y proporcionan una herramienta de evaluación retrospectiva para preservar la salud neonatal durante el nacimiento (Williams y Singh, 2002). Es importante señalar que estas técnicas de evaluación eran
Oronasopharyngeal suction (ONPS) with a suction bulb at birth is a traditional practice in the initial management of healthy infants in Iran and many other countries. The purpose of this study was to compare the effects of oronasopharyngeal suction (ONPS) with those of no suction in normal, term newborns delivered vaginally. A total of 170 healthy term infants of first and single uncomplicated pregnancies, with clear amniotic fluid, vaginal delivery and cephalic presentation, enrolled in the trial during labour. Newborns were randomised into one of the two groups, according to the use of the ONPS procedure. Arterial oxygen saturation (SaO2) levels, heart rates, blood gases of umbilical cord and Apgar scores were determined. The mean SaO2 values over the 1st and 5th min of birth were similar in the two groups. The maximum time to reach SaO2 of ≥ 92% was shorter in the no suction group. There were no statistically significant differences in the mean of heart rates, respiratory rates and Apgar scores between the groups. Apgar scores at 5 and 10 min were between 8 and 10 for all infants, respectively. Newborns receiving suction showed a statistically significant, lower mean partial carbon dioxide pressure (PCO2) and a significantly higher partial oxygen pressure (PO2) of umbilical artery. Although findings remained on the statistical level, these were not considered clinically significant because values remained within normal ranges. According to this study, ONPS is not recommended as a routine procedure in normal, term infants delivered vaginally.
Transfusion of blood products is a cornerstone in managing many critically ill children. Major improvements in blood product safety have not diminished the need for caution in transfusion practice. In this review, we aim to discuss the interplay between benefits and potential adverse effects of transfusion in critically ill children by including 65 papers, which were evaluated based on previously agreed selection criteria. Current practice on transfusing critically ill children is mainly founded on the basis of adult studies, common practices with cut-off values, and expert opinions, rather than evidence-based medicine. Paediatric patients have explicit physiological challenges and requirements to be addressed. Critically ill children often suffer from anaemia, have substantial iatrogenic blood loss with subsequent transfusions, and are at a higher risk of complications, often due to human errors. Transfusion in children is associated with increased morbidity. A restrictive transfusion strategy is not associated with increased morbidity. Thus, transfusion in paediatrics should be considered a high-risk treatment and requires individual clinical assessment. Current level of evidence support the notion that in most stable cases, despite high severity of illness (cyanotic children and neonates excluded), a restrictive haemoglobin threshold of 70 g/l (4.3 mmol/l) is no more harmful than to transfuse at a liberal trigger, e.g. haemoglobin 95 g/l (5.9 mmol/l). Thus, balanced against potential benefits and often its necessity, a restrictive approach may be appropriate due to the associated risks of transfusion.
Birth asphyxia is often associated with a high seizure burden that is predictive of poor neurodevelopmental outcome. The mechanisms underlying birth asphyxia seizures are unknown. Using an animal model of birth asphyxia based on 6-day-old rat pups, we have recently shown that the seizure burden is linked to an increase in brain extracellular pH that consists of the recovery from the asphyxia-induced acidosis, and of a subsequent plateau level well above normal extracellular pH. In the present study, two-photon imaging of intracellular pH in neocortical neurons in vivo showed that pH changes also underwent a biphasic acid-alkaline response, resulting in an alkaline plateau level. The mean alkaline overshoot was strongly suppressed by a graded restoration of normocapnia after asphyxia. The parallel post-asphyxia increase in extra- and intracellular pH levels indicated a net loss of acid equivalents from brain tissue that was not attributable to a disruption of the blood-brain barrier, as demonstrated by a lack of increased sodium fluorescein extravasation into the brain, and by the electrophysiological characteristics of the blood-brain barrier. Indeed, electrode recordings of pH in the brain and trunk demonstrated a net efflux of acid equivalents from the brain across the blood-brain barrier, which was abolished by the Na/H exchange inhibitor, N-methyl-isobutyl amiloride. Pharmacological inhibition of Na/H exchange also suppressed the seizure activity associated with the brain-specific alkalosis. Our findings show that the post-asphyxia seizures are attributable to an enhanced Na/H exchange-dependent net extrusion of acid equivalents across the blood-brain barrier and to consequent brain alkalosis. These results suggest targeting of blood-brain barrier-mediated pH regulation as a novel approach in the prevention and therapy of neonatal seizures.
The present overview is aimed at reporting the standard primary investigations that are mandatory in preterm and term newborns at admission to neonatal unit in the first hours after birth. Herein, the main neonatal screening tests for early detection of metabolic diseases are described as well as laboratory standard procedures (glycaemia, bilirubin, blood gas, infectious diseases analyses) monitoring parameters (vital signs recordings, blood and transcutaneous gas assessment, blood pressure recordings) and ultrasound pattern (cranial and cardiac).
The mechanisms whereby birth asphyxia leads to generation of seizures remain unidentified. To study the possible role of brain pH changes, we used a rodent model that mimics the alterations in systemic CO(2) and O(2) levels during and after intrapartum birth asphyxia.
Neonatal rat pups were exposed for 1 hour to hypercapnia (20% CO(2) in the inhaled gas), hypoxia (9% O(2)), or both (asphyxic conditions). CO(2) levels of 10% and 5% were used for graded restoration of normocapnia. Seizures were characterized behaviorally and utilizing intracranial electroencephalography. Brain pH and oxygen were measured with intracortical microelectrodes, and blood pH, ionized calcium, carbon dioxide, oxygen, and lactate with a clinical device. The impact of the postexposure changes in brain pH on seizure burden was assessed during 2 hours after restoration of normoxia and normocapnia. N-methyl-isobutyl-amiloride, an inhibitor of Na(+) /H(+) exchange, was given intraperitoneally.
Whereas hypercapnia or hypoxia alone did not result in an appreciable postexposure seizure burden, recovery from asphyxic conditions was followed by a large seizure burden that was tightly paralleled by a rise in brain pH, but no change in brain oxygenation. By graded restoration of normocapnia after asphyxia, the alkaline shift in brain pH and the seizure burden were strongly suppressed. The seizures were virtually blocked by preapplication of N-methyl-isobutyl-amiloride.
Our data indicate that brain alkalosis after recovery from birth asphyxia plays a key role in the triggering of seizures. We question the current practice of rapid restoration of normocapnia in the immediate postasphyxic period, and suggest a novel therapeutic strategy based on graded restoration of normocapnia.
To evaluate the accuracy in transcutaneous (Tc) blood gas monitoring in newborn infants, including extremely low birth weight infants, during neonatal intensive care.
Tc PO(2) /PCO(2) was monitored in the neonatal intensive care unit (NICU) during stable infant conditions. In comparison, simultaneous arterial PO(2) and PCO(2) was measured. Sixty measurements were taken in 46 infants with median (range) birth weight of 0.93 (0.53-4.7) kg and at median (range) age of 8.5 (1-44) days. Comparison of measurements was performed using Bland-Altman plots, and the mean (95% CI) of the difference was calculated. Comparison was also performed in relation to body weight, postnatal age and oxygen requirement.
The mean (95% CI) difference in PO(2) (TcPO(2)-aPO(2)) was 0.3 (-0.2-0.9) kPa, and the corresponding difference in PCO(2) (TcPCO(2)-aPCO(2)) was 0.4 (0.03-0.8, p < 0.05) kPa. Some differences were related to body weight, age and oxygen requirement, but these differences were small.
There was good agreement between TcPO(2)/TcPCO(2) and corresponding arterial measurements. The mean difference between the methods was small and clinically acceptable in a current NICU. Tc blood gas monitoring could be recommended as a valuable complement for blood gas monitoring also in extremely low birth weight infants.
In recent years, there has been an increase in the popularity of light-emitting diode (LED)-based, battery-powered transilluminators (BPTs) for facilitating transdermal vascular access in adults and neonates. BPTs are believed to have lower potential for inducing skin burns than prior devices based on high-power broadband lamps; however, the optical and thermal outputs of BPTs are not well documented and safety limits for these devices are not well established. In this study, we characterize and assess the optical and thermal outputs of six BPTs that incorporate red, orange and white LEDs. Optical measurements included spectral irradiance and peak local irradiance. Thermal measurements included transient temperature readings for an exposure time of 4 min in ambient air and ex vivo tissue pre-heated to physiological temperatures. The greatest mean temperature rise produced in tissue by a non-white-light diode BPT was 2.5 degrees C, whereas a mean temperature rise of 9.1 degrees C was measured in a BPT that incorporated white-light diodes with relatively high irradiance levels. The dominant cause of temperature rise was most likely heat generation within the devices. Thermal damage analyses based on temperature limits and the Arrhenius equation indicate that although some of the devices studied approach the threshold for damage, none appear to exceed it under normal operating conditions. The results demonstrated that ambient air measurements may be suitable for identifying worst-case BPT temperatures. This study highlights the potential risk of LED-based medical devices as well as the need for additional research on related issues such as neonatal thermal injury thresholds.
In this case study report of an infant with metabolic alkalosis, the healthcare team worked to discover the cause of the illness. They found that well-meaning parents had diluted their newborn's powdered formula with electrolyte-enhanced water. Electrolyte balance in the newborn is reviewed in this article, along with information about enhanced waters. It is essential that nurses working with new families be aware that heavily advertised enhanced waters could be used unknowingly by parents for their newborns, and that the consequences could be dire.
Previously, we reported that the hypoxic ventilatory response (HVR) in rats was weakest at postnatal day (P) P13, concomitant with neurochemical changes in respiratory nuclei. A major determinant of minute ventilation (Ve) is reportedly the metabolic rate [O(2) consumption (Vo(2)) and CO(2) production (Vco(2))]. The present study aimed at testing our hypothesis that daily metabolic rates changed in parallel with ventilation during development and that a weak HVR at P13 was attributable mainly to an inadequate metabolic rate in hypoxia. Ventilation and metabolic rates were monitored daily in P0-P21 rats. We found that 1) ventilation and metabolic rates were not always correlated, and Ve/Vo(2) and Ve/Vco(2) ratios were not constant during development; 2) metabolic rate and Ve/Vo(2) and Ve/Vco(2) ratios at P0-P1 were significantly different from the remaining first postnatal week in normoxia and hypoxia; 3) at P13, metabolic rates and Ve/Vo(2) and Ve/Vco(2) ratios abruptly increased in normoxia and were compromised in acute hypoxia, unlike more stable trends during the remaining second and third postnatal weeks; and 4) the respiratory quotient (Vco(2)/Vo(2)) was quite stable in normoxia and fluctuated slightly in hypoxia from P0 to P21. Thus our data revealed heretofore unsuspected metabolic adjustments at P0-P1 and P13. At P0-P1, ventilation and metabolic rates were uncorrelated, whereas at P13, they were closely correlated under normoxia and hypoxia. The findings further strengthened the existence of a critical period of respiratory development around P13, when multiple physiological and neurochemical adjustments occur simultaneously.
The arterial partial pressure of carbon dioxide (PaCO2) represents the balance between CO2 production and consumption. Abnormal increase or decrease in PaCO2 can affect the body's internal environment and function. Permissive hypercapnia has aroused more attention as a novel ventilatory therapy. The aim of this study was to elucidate the effects of hypercapnia and hypocapnia on the functions of such neonatal organs as the lung and brain.
The PubMed database was searched with the keywords "hypocapnia", "hypercapnia" and "newborn".
Hypocapnia is a risk factor for potential damage to the central nervous system, such as periventricular leukomalacia, intraventricular hemorrhage, cerebral palsy, cognition developmental disorder, and auditory deficit. Hyperventilation can lessen pulmonary artery hypertension to certain extent, but hypocapnia can aggravate ischemia/reperfusion-induced acute lung injury. Severe hypercapnia can induce intracranial hemorrhage, even consciousness alterations, cataphora, and hyperspasmia. Permissive hypercapnia can improve lung injury caused by diseases of the respiratory system, lessen mechanical ventilation-associated lung injury, reduce the incidence of bronchopulmonary dysplasia and protect against ventilation-induced brain injury. In addition, permissive hypercapnia plays a role in expanding cerebral vessels and increasing cerebral blood flow.
Severe hypercapnia and hypocapnia can cause neonatal brain injury and lung injury. Permissive hypercapnia can increase the survival of neonates with brain injury or respiratory system disease, and lessen the brain injury and lung injury caused by mechanical ventilation. However, the mechanism of permissive hypercapnia needs further exploration to confirm its safety and therapeutic utility.
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