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Retrograde Autologous Priming in Cardiac Surgery: Results From a Systematic Review and Meta-analysis
Abstract
Background:
Retrograde autologous priming (RAP) before cardiopulmonary bypass (CPB) may minimize allogeneic red cell transfusion. We conducted a systematic review of the literature to examine the impact of RAP on perioperative allogeneic red cell transfusions in cardiac surgical patients.
Methods:
This study involved a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies evaluating the use of RAP in cardiac surgery involving CPB. The primary outcome was intraoperative allogeneic red cell transfusion. Secondary outcomes included whole hospital allogeneic transfusions and adverse events such as acute kidney injury (AKI) and stroke.
Results:
A total of 11 RCTs (n = 1337 patients) were included, comparing RAP patients (n = 674) to control (n = 663). In addition, 10 observational studies (n = 2327) were included, comparing RAP patients (n = 1257) to control (n = 1070). Overall, RAP was associated with a significantly reduced incidence of intraoperative red cell transfusion (n = 18 studies; odds ratio [OR] = 0.34; 95% confidence interval [CI], 0.22-0.55, P < .001) compared to controls. This effect was seen among RCTs (n = 10 studies; OR = 0.19; 95% CI, 0.08-0.45, P < .001) and observational studies (n = 8 studies; OR = 0.66; 95% CI, 0.50-0.87, P = .004) in isolation. RAP was also associated with a significantly reduced incidence of whole hospital red cell transfusion (n = 5 studies; OR = 0.28; 95% CI, 0.19-0.41, P < .001). Among the studies that reported AKI and stroke outcomes, there was no statistically significant increased odds of AKI or stroke in either RAP or control patients.
Conclusions:
Based on the pooled results of the available literature, RAP is associated with a significant reduction in intraoperative and whole hospital allogeneic red cell transfusion. Use of RAP may prevent hemodilution of cardiac surgical patients and thus, lessen transfusions. Additional high-quality prospective studies are necessary to determine the ideal priming volume necessary to confer the greatest benefit without incurring organ injury.
... The third week of the internship is intended to deepen the content learned in the second week. In addition, the theoretical content will be transferred into practice and the theories for calculations of homologous blood utilization and the correction of the values from the blood gas analysis (BGA) on the basis of Goal directed Perfusion (GDP) parameters [11][12][13] and corresponding techniques such as retrograde autologous priming (RAP) 14,15 and demonstrated the calculation and administration of drugs in practice. With the connection of the table lines in compliance with the rules for asepsis in the operating room, the practical work with the HLM in the operating room begins. ...
... There is a detailed briefing on the perfusion-relevant points of cannulation and blood-saving techniques such as the RAP and the basic rules for the subsequent admission of the ECC. 3,14,[16][17][18][19][20] During perfusion, the student begins to take over the control of the suction pumps as well as the documentation in the PDMS. Further instructions on the theories of cardioplegia and the procedure used in each case and the dependent parameters follow. ...
Background
Increasing regulations and requirements of advisory bodies, in particular the Joint Federal Committee and the Medical Service of the health insurance funds, make it necessary to employ only demonstrably well-trained perfusionists. The minimum requirement for this staff is EBCP certification. Currently there is limited availability of such specialists on the German market. Therefore, the qualification of young people in this area is of central importance. The aim of this paper is to strengthen the training of perfusionists at our centre, to standardise the process and to provide the respective student with a “roadmap” to their internship.
Material & Methods
The structure is based on a rough division of the 24 weeks of internship. This is described in detail in the following and is backed up with the learning objectives for the respective time periods.
Results
At our centre, practical training has been standardized and clear responsibilities have been defined. Furthermore, as a centre of maximum care in the field of cardiac surgery, we can offer students the necessary number of perfusions in just six months to meet the requirements of the ECBP for practical training. According to this concept, 20 perfusionists have been successfully trained in the last 8 years. All of them have passed the exams and have been certified according to EBCP.
Conclusion
The aim of the practical semester is for the student to be in a position at the end of the semester to independently supervise simple cardiac surgery procedures with the aid of the Extra- Corporal Circulation (ECC) and to carry this out in accordance with the currently valid guidelines and directives (1–8) and the departmental procedural instructions based on them. Great emphasis is placed to the students becoming aware of their competence to act, knowing their limits and being able to assess when these limits have been reached and the involvement of experienced colleagues is necessary to ensure patient safety.
... 1 The retrograde autologous priming (RAP) procedure minimizes hemodilution by replacing circuit priming fluid with the patient's blood, which is drained passively through arterial and venous lines before the initiation of CPB. Since its introduction in clinical practice by Rosengart et al. in 1998, 2 RAP has been suggested to be a safe and convenient blood conservation technique, 3,4 and recommended as one of the components of patient blood management (PBM). 5 Previous studies on RAP have focused primarily on the preservation of hemoglobin (Hb) concentration and reduction of erythrocyte transfusion. ...
... 5 Previous studies on RAP have focused primarily on the preservation of hemoglobin (Hb) concentration and reduction of erythrocyte transfusion. 4,6 However, hemodilution from the priming fluid theoretically reduces not only erythrocyte concentrations but also coagulation factor concentrations and platelet counts in the blood. 7,8 Furthermore, CPB-induced activation of the hemostatic system and consumption of coagulation factors may lead to post-CPB coagulopathy. ...
... 93 A further meta-analysis has found similar results with regards to AKI, although once again red blood cell transfusion was reduced. 94 European guidance recommends RAP (Class 1, Level A Evidence) on the basis of reduction in transfusion load, rather than a direct impact upon AKI. 89 Priming fluid. ...
Cardiac surgery on cardiopulmonary bypass (CPB) is associated with postoperative renal dysfunction, one of the most common complications of this surgical cohort. Acute kidney injury (AKI) is associated with increased short-term morbidity and mortality and has been the focus of much research. There is increasing recognition of the role of AKI as the key pathophysiological state leading to the disease entities acute and chronic kidney disease (AKD and CKD). In this narrative review, we will consider the epidemiology of renal dysfunction after cardiac surgery on CPB and the clinical manifestations across the spectrum of disease. We will discuss the transition between different states of injury and dysfunction, and, importantly, the relevance to clinicians. The specific facets of kidney injury on extracorporeal circulation will be described and the current evidence evaluated for the use of perfusion-based techniques to reduce the incidence and mitigate the complications of renal dysfunction after cardiac surgery.
... The accumulation of extravascular fluid induces interstitial edema and corresponding organ dysfunction [1,2]. In addition, due to damage caused by contact between blood and the artificial material in CPB circuitry and substantial bleeding during open chest procedures, patients usually develop severe intraoperative and postoperative anemia, which is associated with increased morbidity and mortality [3]. Although allogeneic red cell transfusions are performed on approximately 40-60% of patients undergoing cardiac valve replacement during hospitalization, growing evidence suggests an association between blood transfusion and unfavorable morbidity, mortality, and longterm outcomes after cardiac surgery [4][5][6]. ...
Background
The adverse effects of cardiopulmonary bypass during open cardiac surgery, including hemodilution, seem to be inevitable, especially for patients who generally have a relatively lower BMI with relatively small blood volumes. This study reports the modification and use of a cardiopulmonary bypass (CPB) system to reduce priming volume and hemodilution.
Methods
This is a retrospective study of 462 adult patients who underwent cardiac valve replacement surgery from January 2019 to September 2021 at the General Hospital of Western Theater Command. The modified group consisted of 212 patients undergoing modified CPB. The control group included 250 patients receiving conventional CPB. Evaluated indices included fluid intake and output volumes during CPB, intraoperative indices related to CPB operation, usage of blood products during the peri-CPB period, and postoperative outcomes.
Results
The modified group displayed a significant reduction in the crystalloid (200 mL vs. 600 mL, P < 0.05) and colloid priming volumes (450 mL vs. 1100 mL, P < 0.05), and ultrafiltration solution volume (750 mL vs. 1200 mL, P < 0.05). Furthermore, the modified group had a significantly lower rate of defibrillation (30.2% vs. 41.2%, P < 0.05). The intraoperative urine volume (650 mL vs. 500 mL, P < 0.05) and intraoperative hematocrit (Hct) (26% vs. 24%, P < 0.05) of the modified CPB group were also higher than in the control group. The modified group required a lower infusion volume of packed red blood cells (250 mL vs. 400 mL, P < 0.05) and lower infusion rates of packed red blood cells (17.9% vs. 25.2%, P < 0.05) and fresh frozen plasma (1.41% vs. 5.2%, P < 0.05). In addition, the modified group showed significantly improved indices related to postoperative recovery.
Conclusions
The modified CPB system effectively conserves blood and shows noteworthy potential for application in cardiac valve replacement surgery.
... 22 Retrograde autologous priming was reported to be associated with a significant reduction in the need for intraoperative whole blood transfusion and the prevention of hemodilution in cardiac surgical patients. 23,24 To prevent severe hemodilution during CPB in surgery for ATAAD, other options, such as reducing the prime volume by using smaller circuits 25 and ultrafiltration during CPB, 26 may be considered especially for patients with risk factors for lower nadir Hct value during CPB; however, these options may not be always appropriate in emergent cases and may increase costs. ...
Objective
Although hemodilution during hypothermic cardiopulmonary bypass (CPB) had been thought to improve microcirculation and reduce blood viscosity, there has been no report investigating the effect of low nadir hematocrit (Hct) values caused by severe hemodilution on the surgical outcomes of patients with acute type A aortic dissection (ATAAD).
Methods
We retrospectively reviewed 112 consecutive patients who emergently underwent emergency surgical repair of ATAAD at our institution. The patients were classified into the high Hct (nadir Hct ≥ 21% during CPB; n = 51) and low Hct (nadir Hct < 21% during CPB; n = 61) groups. After propensity score matching of preoperative characteristics, surgical outcomes were compared between the groups.
Results
Although there was no difference in the surgical procedure, longer CPB time and more blood transfusion during surgery were needed in the low Hct group than in the high Hct group. After surgery, estimated glomerular filtration rate was significantly lower (p = .015), lactaic acid was higher (p = .045), and intubation time was longer (p = .018) in the low Hct group than in the high Hct group, although there was no difference in hospital mortality between the groups. The AUC of the nadir Hct during CPB as a prognostic indicator of prolonged postoperative ventilator support was 0.8, with the highest accuracy at 16.7% (sensitivity 88%, specificity 76.9%). In all cohorts, female sex was an independent risk factor for a lower nadir Hct value of <21% during CPB.
Conclusion
A lower nadir Hct value of <21% during CPB may be associated with postoperative renal dysfunction and prolonged ventilator support in patients with ATAAD.
... Multiple randomized trials have demonstrated that RAP and VAP reduce the incidence of blood transfusions. 9,10,39 The strength of the evidence has led to a Class I recommendation for performing RAP within the 2021 combined STS, SCA, American Society of ExtraCorporeal Technology, and Society for the Advancement of Blood Management guidelines for patient blood management. 9 Performing RAP and VAP requires close communication between the anesthesiologist and perfusionist in order to maintain hemodynamic stability during the priming. ...
Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.
Introduction
Retrograde Autologous Priming (RAP) of cardiopulmonary bypass (CPB) circuits is an effective way to reduce prime volume, commonly through the transfer of prime into separate reservoirs or circuit manipulation. We describe a simple and safe technique for RAP without the need for any circuit modifications or manipulations.
Methods
For this technique, a separate roller pump for ultrafiltration (UF) is used. After adequate heparinization and arterial cannulation, the UF pump is initiated slowly, removing prime through the effluent of the UF, replacing with the patient’s blood from the aortic cannula. Once the arterial line and UF circuit are autologous primed, the arterial head displaces reservoir crystalloid toward the UF circuit at a flow rate equal to the UF pump, displacing the crystalloid prime with blood from the UF circuit, autologous priming the boot and oxygenator with blood, crystalloid again being removed by the effluent. After venous cannulation, the venous line prime is replaced with autologous blood, the crystalloid removed by the effluent of the UF circuit via the arterial head. During RAP, if the patient becomes hypovolemic, either autologous volume is transfused back to the patient, or CPB is initiated, without the need for circuitry modifications.
Results
The patient population in this sample consisted of 63 patients ranging between 6.1 kg and 115.6 kg. The smaller the patient, the less blood volume available for RAP and therefore the less prime volume able to be removed. Overall percent removal increases as our patients size increases compared to total circuit volume.
Conclusion
This RAP technique is a safe and effective way to achieve a standardized asanguinous prime for many regardless of patient or circuit size in the absence of contraindications such as low starting hematocrit, emergency surgery or physiologic instability. Most importantly, this potentially reduces the amount of hemodilution patients see from CPB initiation and therefore the lowest nadir hematocrit and consequently the amount of required homologous blood products needed during surgery.
BACKGROUND
Perioperative red blood cell (RBC) transfusions increase venous thromboembolic (VTE) events. Although a previous study found that plasma resuscitation after trauma was associated with increased VTE, the risk associated with additional perioperative plasma is unknown.
METHODS
A US claims and EHR database (TriNetX Diamond Network) was queried. We compared surgical patients who received perioperative plasma and RBC to patients who received perioperative RBC but not plasma. Subanalyses included (1) all surgeries (n = 48,580) and (2) cardiovascular surgeries (n = 38,918). Propensity score matching was performed for age at surgery, ethnicity, race, sex, overweight and obesity, type 2 diabetes, disorders of lipoprotein metabolism, essential hypertension, neoplasms, nicotine dependence, coagulopathies, sepsis, chronic kidney disease, liver disease, nonsteroidal anti-inflammatory analgesics, platelet aggregation inhibitors, anticoagulants, hemoglobin level, outpatient service utilization, and inpatient services; surgery type was included for “all surgeries” analyses. Outcomes included 30-day mortality, postoperative VTE, pulmonary embolism (PE), and disseminated intravascular coagulation (DIC).
RESULTS
After matching the surgical cohorts, compared to only RBC, plasma + RBC was associated with higher risk of postoperative mortality (4.52% vs 3.32%, risk ratio [RR]: 1.36 [95% confidence interval, 1.24–1.49]), VTE (3.92% vs 2.70%, RR: 1.36 [1.24–1.49]), PE (1.94% vs 1.33%, RR: 1.46 [1.26–1.68]), and DIC (0.96% vs 0.35%, RR: 2.75 [2.15–3.53]). Among perioperative cardiovascular patients, adding plasma to RBC transfusion was associated with similar increased risk.
CONCLUSIONS
When compared with perioperative RBC transfusion, adding plasma was associated with increased 30-day postoperative mortality, VTE, PE, and DIC risk among surgical and cardiovascular surgical patients. Reducing unnecessary plasma transfusion should be a focus of patient blood management to improve overall value in health care.
Objectives:
A conservative hemoglobin transfusion threshold is noninferior to a liberal threshold in cardiac surgery. However, red blood cell (RBC) transfusion remains common during cardiac surgery. The authors' single-center, retrospective study aimed to decrease RBC transfusions for hemoglobin >7.5 g/dL in nonemergent cardiovascular surgeries utilizing cardiopulmonary bypass (CPB), by educating the anesthesiology and surgical staff on the benefits of a conservative threshold for transfusions, and incorporating the discussion and routine use of blood conservation methods for all nonemergent cardiac surgeries.
Design:
This was a single-center, retrospective study that included all nonemergent coronary artery bypass grafting and single-valve cases utilizing CPB from January 2018 to December 2021 before and after the intervention in July 2019.
Setting:
The data involved a single community hospital.
Participants:
A total of 417 patients were included in the study.
Interventions:
The authors adopted a conservative threshold for blood transfusion and implemented a collaborative multidisciplinary approach to blood conservation.
Measurements and main results:
Baseline patient characteristics were summarized, and the incidence of RBC transfusion before and after the intervention on July 26, 2019, were compared by Wilcoxon rank sum and chi-square tests. Multivariate logistic regression was used. The intervention was significantly associated with reduced RBC transfusion rate after adjusting for confounding variables (p < 0.05). The odds of receiving an RBC transfusion among patients after the intervention was 0.615 times the odds among patients before intervention (95% CI: 0.3913-0.9663).
Conclusions:
The authors' goal was to improve patient outcomes and the quality of perioperative care during cardiac surgery. By implementing a protocol and educating anesthesiologists, surgeons, and perfusionists, they successfully decreased the incidence of RBC transfusion above a hemoglobin of 7.5 g/dL.
Background:
Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure in the world and up to one-third of patients are transfused red blood cells (RBCs). RBC transfusion may increase the risk for health care-associated infection (HAI) after CABG, but previous studies have shown conflicting results and many did not establish exposure temporality. Our objective was to explore whether intraoperative RBC transfusion is associated with increased odds of postoperative HAI. We hypothesized that intraoperative RBC transfusion would be associated with increased odds of postoperative HAI.
Methods:
We performed an observational cohort study of isolated CABG patients in the Society of Thoracic Surgeons adult cardiac surgery database from July 1, 2017, to June 30, 2019. The exposure was intraoperative RBC transfusion modeled as 0, 1, 2, 3, or 4+ units. The authors focused on intraoperative RBC transfusion as a risk factor, because it has a definite temporal relationship before postoperative HAI. The study's primary outcome was a composite HAI variable that included sepsis, pneumonia, and surgical site infection (both deep and superficial). Mixed-effects modeling, which controlled for hospital as a clustering variable, was used to explore the relationship between intraoperative RBC transfusion and postoperative HAI.
Results:
Among 362,954 CABG patients from 1076 hospitals included in our analysis, 59,578 patients (16.4%) received intraoperative RBCs and 116,186 (32.0%) received either intraoperative or postoperative RBCs. Risk-adjusted odds ratios for HAI in patients who received 1, 2, 3, and 4+ intraoperative RBCs were 1.11 (95% confidence interval [CI], 1.03-1.20; P = .005), 1.13 (95% CI, 1.05-1.21; P = .001), 1.15 (95% CI, 1.04-1.27; P = .008), and 1.14 (95% CI, 1.02-1.27; P = .02) compared to patients who received no RBCs.
Conclusions:
Intraoperative RBC transfusion is associated with a small increase in odds of HAI in CABG patients. Future studies should explore whether reductions in RBC transfusion can also reduce HAIs.
Objectives
: Little is known about the safety and clinical utility of retrograde autologous priming (RAP) in patients undergoing minimally invasive mitral valve surgery. We hypothesized that RAP would increase the oxygen delivery index (DO2i) while decreasing red blood cells transfusion requirements compared to valve surgery without RAP.
Design
: The study was an observational analysis.
Setting
: Single institutional study.
Partecipants
: We analyzed data from 500 consecutive patients who underwent minimally invasive isolated mitral valve repair from December 31, 2012 to December 31, 2019.
Intervention
: RAP was performed in 235 patients (47%) prior to the initiation of cardiopulmonary bypass (CPB).
Measurement and Main Results
: A continuous monitoring system was used for DO2 management during CPB. Mean arterial pressure was maintained between 55 and 70 mmHg and cardiac index was set at 2.4 L/min/m² with adjustments in accordance with DO2i. The trigger point for red cell blood transfusion during CPB was hemoglobin <7 g/dL.
Baseline hematocrit was lower in the RAP group compared to the no-RAP group (33.4±3.6 vs. 38.1±4.9, respectively; p<0.001). Both CPB and cross clamp times were similar between groups. Hematocrit during CPB was significantly higher in the RAP group compared to the no-RAP group (27.6±2.6 vs 25.9±5.1, respectively; p<0.001). RAP was also associated with significantly higher mean DO2i (292±19.5 vs. 282.9±35.1 mL/min/m², respectively; p<0.001) and fewer red blood cells transfusions during the intraoperative and immediate post-operative periods (p<0.001).
Conclusions
: In a minimally invasive mitral valve context, RAP was safe and associated with better DO2i, higher hematocrit, and fewer intra- and post-operative red blood cells transfusions.
Objective
To evaluate racial/ethnic and sex disparities in allogenic and autologous red blood cell (RBC) transfusions in cardiac surgery.
Design
Retrospective observational study.
Setting
2007-2018 data from Florida, Maryland, Kentucky, Washington, New York, California from the State Inpatient Databases (SID), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality (AHRQ).
Participants
710,296 inpatients who underwent elective or emergency coronary artery bypass grafting (CABG), cardiac valve surgery, combination CABG/valve surgery.
Interventions
none
Measurements
Patients were cohorted by race/ethnicity and sex as defined by SID-HCUP. Demographic characteristics and comorbidities were compared. Rates and risk-adjusted odds ratios (aOR) were calculated for allogenic and autologous RBC transfusion (primary outcomes). Additional secondary analyses were conducted for in-hospital mortality, 30-day readmission, 90-day readmission, hospital length of stay (LOS) and total charges to examine the effect of RBC transfusion status. Effect modification between race and sex was assessed.
Main results
When controlling for patient demographics, comorbidities and hospital characteristics, non-white patients were more likely to receive an allogenic RBC transfusion during cardiac surgery than white patients (Black: aOR 1.17, 99% CI 1.13-1.20, p< 0.001, Hispanic: aOR 1.22, 99% CI 1.19-1.22, p< 0.001). Women were more likely to receive allogenic RBC than men (aOR 1.69, 99% CI 1.66-1.72, p<0.001). In interaction models, non-white females had the highest odds of allogenic blood transfusion as compared to white males (reference category; Black female: aOR 2.04, 99% CI 1.91-2.17, p< 0.001, Hispanic female: aOR 2.03, 99% CI 1.90-2.16, p< 0.001).
Conclusions
These findings highlight the differences in rates of allogenic RBC transfusion for non-white and female patients undergoing cardiac surgery, which is a well-established marker of poorer outcomes.
Background:
Postoperative hyperlactatemia (POHL) is common in patients undergoing cardiac surgery, associated with adverse outcomes. The aim of this study was to identify predictors for POHL after cardiac surgery and to develop and validate a predictive model.
Methods:
Adult patients who underwent open heart surgery at our institution between 2016 and 2019 were retrospectively included. The patients were randomly divided into training and validation groups at a 2:1 ratio. Multivariate logistic regression was performed to identify independent predictors for POHL in the training set. A nomogram was then constructed and was validated in the validation set.
Results:
POHL developed in 713 of the 5,323 patients (13.4%). The mortality rate was higher in patients with POHL compared with patients without that (9.5% vs. 2.1%, P<0.001). Age, white blood cell (WBC) count, left ventricular ejection fraction, renal insufficiency, cardiac surgery history, red blood cell (RBC) transfusion, and cardiopulmonary bypass (CPB) time were identified as independent risk factors. The nomogram based on these predictors indicated good discrimination in both the training (c-index: 0.787) and validation (c-index: 0.820) sets. The calibration was reasonable by both visual inspection and goodness-of-fit test. The decision and clinical impact curves demonstrated good clinical utility.
Conclusions:
We identified 7 independent risk factors and derived a prediction model for POHL in patients undergoing cardiac surgery. The model may contribute significantly to early risk assessment and clinical intervention.
Patient blood management (PBM) is an important component of quality cardiac surgical care. Through anaemia management, coagulation optimization, blood conservation modalities and patient-centred decision-making, PBM aims to improve blood conservation and patient outcomes [1]. In particular, retrograde autologous priming (RAP) of the cardiopulmonary bypass (CPB)\ circuit is becoming an increasingly common blood conservation strategy in adult cardiac surgery. Routine use of RAP varies across institutions, from <20% in European and Australian centres up to ∼62% in Canadian centres [2, 3]. While major societal guidelines generally promote the use of RAP, the recommendations were based on low- to moderate-quality evidence including systematic reviews of observational studies and small randomized controlled trials (RCTs) [1, 4] In their systematic review and meta-analysis, Gupta et al. [5] conducted a more comprehensive evaluation of the safety and efficacy of RAP in adult cardiac surgery patients to validate the guidelines’ recommendations based on the best available evidence to date.
Background:
Stroke is a leading cause of morbidity, mortality, and disability in patients undergoing cardiac surgery. Identifying modifiable perioperative stroke risk factors may lead to improved patient outcomes. The association between the severity and duration of intraoperative hypotension and postoperative stroke in patients undergoing cardiac surgery was evaluated.
Methods:
A retrospective cohort study was conducted of adult patients who underwent cardiac surgery requiring cardiopulmonary bypass at a tertiary center between November 1, 2009, and March 31, 2015. The primary outcome was postoperative ischemic stroke. Intraoperative hypotension was defined as the number of minutes spent within mean arterial pressure bands of less than 55, 55 to 64, and 65 to 74 mmHg before, during, and after cardiopulmonary bypass. The association between stroke and hypotension was examined by using logistic regression with propensity score adjustment.
Results:
Among the 7,457 patients included in this analysis, 111 (1.5%) had a confirmed postoperative diagnosis of stroke. Stroke was strongly associated with sustained mean arterial pressure of less than 64 mmHg during cardiopulmonary bypass (adjusted odds ratio 1.13; 95% CI, 1.05 to 1.21 for every 10 min of mean arterial pressure between 55 and 64 mmHg; adjusted odds ratio 1.16; 95% CI, 1.08 to 1.23 for every 10 min of mean arterial pressure less than 55 mmHg). Other factors that were independently associated with stroke were older age, hypertension, combined coronary artery bypass graft/valve surgery, emergent operative status, prolonged cardiopulmonary bypass duration, and postoperative new-onset atrial fibrillation.
Conclusions:
Hypotension is a potentially modifiable risk factor for perioperative stroke. The study's findings suggest that mean arterial pressure may be an important intraoperative therapeutic hemodynamic target to reduce the incidence of stroke in patients undergoing cardiopulmonary bypass.
Background:
Adult cardiac surgery with extracorporeal circulation is known to be associated with increased risk of blood transfusion leading to adverse outcomes. Procedures like retrograde autologous priming (RAP) may reduce these negative side effects. This randomized prospective study was initiated to assess whether RAP using specifically designed RAP bag (Terumo) has immediate effects on patient outcome.
Methods:
One hundred eighteen adults undergoing elective CABG or elective aortic valve replacement were randomly assigned by a computer program into two groups: the RAP group (n = 54) in which the retrograde autologous priming was applied and the non-RAP (n = 64) group in which the same setting was used without the possibility to save priming volume. Patient demographics, preoperative characteristics and postoperative outcomes were analyzed for both groups.
Results:
The primary endpoint defined as rate of intraoperative blood transfusion was significantly reduced in the RAP-group (p = 0.04). The absolute risk reduction for RAP managed patients was 13.5 percent points. There were no significant differences in operation time and blood loss. No deaths and no myocardial infarctions were observed. The number of patients needed to treat to prevent at least one red blood cell transfusion was around 8 (NNT = 7.42).
Conclusions:
Retrograde autologous priming is a safe and less invasive procedure which achieves clear benefits for adult cardiac surgery patients. In the light of increasing red blood cell transfusion risks and costs and the wish of patients to avoid a transfusion implementation of retrograde autologous priming is an interesting option.
Trial registration:
German Clinical Trials Register ID: DRKS00013512 , registered 04 December 2017.
Objective:
To clarify the GRADE (grading of recommendations assessment, development and evaluation) definition of certainty of evidence and suggest possible approaches to rating certainty of the evidence for systematic reviews, health technology assessments and guidelines.
Study design and setting:
This work was carried out by a project group within the GRADE Working Group, through brainstorming and iterative refinement of ideas, using input from workshops, presentations, and discussions at GRADE Working Group meetings to produce this document, which constitutes official GRADE guidance.
Results:
Certainty of evidence is best considered as the certainty that a true effect lies on one side of a specified threshold, or within a chosen range. We define possible approaches for choosing threshold or range. For guidelines, what we call a fully contextualized approach requires simultaneously considering all critical outcomes and their relative value. Less contextualized approaches, more appropriate for systematic reviews and health technology assessments, include using specified ranges of magnitude of effect, e.g. ranges of what we might consider no effect, trivial, small, moderate, or large effects.
Conclusion:
It is desirable for systematic review authors, guideline panelists, and health technology assessors to specify the threshold or ranges they are using when rating the certainty in evidence.
Currently, around 35-80% of patients undergoing cardiac surgery in the UK receive a blood transfusion. Retrograde autologous priming (RAP) of the cardiopulmonary bypass circuit has been suggested as a possible strategy to reduce blood transfusion during cardiac surgery.
Data from 101 consecutive patients undergoing isolated coronary artery bypass grafts (where RAP was used) were collected prospectively and compared with 92 historic patients prior to RAP use in our centre.
Baseline characteristics (ie age, preoperative haemoglobin [Hb] etc) were not significantly different between the RAP and non-RAP groups. The mean pump priming volume of 1,013ml in the RAP group was significantly lower (p<0.001) than that of 2,450ml in the non-RAP group. The mean Hb level at initiation of bypass of 9.1g/dl in patients having RAP was significantly higher (p<0.001) than that of 7.7g/dl in those who did not have RAP. There was no significant difference between the RAP and non-RAP groups in transfusion of red cells, platelets and fresh frozen plasma, 30-day mortality, re-exploration rate and predischarge Hb level. The median durations of cardiac intensive care unit stay and in-hospital stay of 1 day (inter-quartile range [IQR]: 1-2 days) and 5 days (IQR: 4-6 days) in the RAP group were significantly shorter than those of the non-RAP group (2 days [IQR: 1-3 days] and 6 days [IQR: 5-9 days]).
In the population group studied, RAP did not influence blood transfusion rates but was associated with a reduction in duration of hospital stay.
Introduction:
Retrograde autologous priming (RAP) of the cardiopulmonary bypass (CPB) circuit could reduce the degree of haemodilution associated with priming with acellular solutions. However, there is no strong evidence to prove that the practice of RAP reduced intraoperative packed red cell (PRC) or blood product transfusion.
Objective:
To evaluate the effect of RAP on intraoperative PRC usage in coronary artery bypass grafting (CABG).
Methods:
This study is a prospective, observational study on patients who underwent first-time, isolated CABG using CPB between April 2012 and July 2012. Two groups of patients were identified: 1. Non-RAP group (n=128) and 2. RAP group (n=73). The primary outcome for the study was the amount of PRC and blood product usage between the induction of anaesthesia and the cessation of CPB.
Results:
Use of PRC and blood products in the operating room was comparable in both groups. Univariate logistic regression showed that RAP was not an independent predictor of PRC or blood product transfusion (p=0.43). Multivariate logistic regression showed that CPB time, preoperative haemoglobin (Hb) levels and creatinine clearance were independent predictors of blood product transfusion.
Conclusion:
Practising RAP with mean volumes of 300 ml does not necessarily reduce PRC and other blood product transfusion requirements during CABG. In our practice, RAP was performed, aiming at displacing CPB circuit prime volume with which the perfusionist felt comfortable and dictated by haemodynamic parameters prior to commencing CPB. We presume this is the case in many units around the world. This practice, in our opinion, is not enough to achieve the benefits of RAP, if any, in the form of a reduction of packed red cell transfusion requirements. The true advantages of RAP in cardiac surgery need to be studied in a prospective, randomized, controlled trial.
OBJECTIVES
Many cardiac procedures using cardiopulmonary bypass (CPB) still require intraoperative transfusion. Retrograde autologous priming (RAP) has been introduced to decrease haemodilution and the blood transfusion rate. This study is designed to determine the influence or RAP on intraoperative haematocrit, transfusion and its clinical consequences.METHODS
The RAP effect was retrospectively studied in 753 patients during contemporary cardiac surgery, targeting a haematocrit of 25%. Multivariate linear regression analysis was performed to identify the independent factors influencing intraoperative haematocrit, transfusion rate and transfusion quantity.RESULTSRAP was used in 498 patients and compared with 255 controls. RAP decreased the haemodilution level (nadir haematocrit 26.8 standard deviation [SD] 4.0% in RAP vs 25.8 SD 3.6% in controls; P = 0.001) and transfusion frequency (26.1 vs 33.3%, P = 0.04), despite smaller patients (body surface area [BSA] 1.86 SD 0.20 m2 vs 1.91 SD 0.21 m2 in RAP vs controls; P = 0.002) with lower preoperative haematocrit (38.9 SD 4.4% vs 40.5 SD 4.6%; P < 0.001). Optimal RAP volume was overall 475 ml (ROC area 0.55; 95% confidence interval [CI] 0.50-0.60; P = 0.04) and 375 ml in patients with BSA <1.7 m2 (ROC area 0.63; 95% CI 0.54-0.73; P = 0.008) to decrease the transfusion incidence. Multivariate analysis revealed RAP volume as a significant determinant of nadir haematocrit (β = 0.003, 95% CI 0.002-0.004, P < 0.001) and transfusion rate (odds ratio (OR) = 0.997, 95% CI 0.996-0.999, P < 0.001), independent of BSA, gender and preoperative haematocrit.CONCLUSION
Retrograde autologous priming is an effective adjunct to decrease the blood transfusion rate, coping with the CPB-related haemodilution and its adverse clinical effects. A RAP volume individualized to each patient offers most benefit as part of a multidisciplinary blood conservation approach.
Background:
Despite recent advances in blood conservation techniques, up to 30% to 80% of patients undergoing open heart operations require allogeneic blood transfusions. A prospective, randomized study was performed to test the effect of lowering cardiopulmonary bypass prime volume (as an additional component of an integrated blood conservation strategy) on clinical outcome and allogeneic blood transfusion.
Methods:
One hundred fourteen patients undergoing open heart operations were randomized to either full prime (FP) volume (1,400 mL of Plasmalyte solution) or reduced prime (RP) volume (600 to 800 mL). The reduction of prime volume was achieved by slowly draining the cardiopulmonary bypass circuit into a cell-saving device before the initiation of bypass. Firm transfusion thresholds were observed.
Results:
There were no significant differences between the groups with respect to baseline characteristics, body surface area, type and urgency of the procedures, perfusion technique, and hematologic profile. Mortality (FP, 1.7%; RP, 0%; p approximately 1.0) and overall morbidity (FP, 28.1%; RP, 22.8%; p = 0.53) were similar. However, transfusion requirements were significantly lower in the RP group: total donor exposure, 3.8 +/- 10.1 versus 1.0 +/- 2.4 units (p = 0.044); percentage of patients transfused, 54% (n = 31) versus 35% (n = 20) (p = 0.036). Twenty-four-hour chest tube drainage was similar: 455 +/- 223 mL for FP versus 472 +/- 173 mL for RP (p = 0.66). The lowest hematocrit on bypass was significantly higher in the RP group: 29.3% +/- 4% versus 26.3% +/- 5.3% (p = 0.009).
Conclusions:
Lowering cardiopulmonary bypass prime volume resulted in a significant decrease in allogeneic blood product use. Because postoperative 24-hour chest tube drainage was similar in both groups, and hematocrit during bypass was higher in the RP group, the reduction in allogeneic blood transfusions appears to be related to a decrease in prime-induced hemodilution. This technique is effective, simple, and safe. It therefore should be strongly considered for patients undergoing operations using normothermic or near-normothermic cardiopulmonary bypass who are at high risk for allogeneic blood transfusion.
Retrograde autologous priming (RAP) is a cardiopulmonary bypass (CPB) method, at low cost. Previous studies have shown that this method reduces hemodilution and blood transfusions needs through increased intra-operative hematocrit.
To evaluate RAP method, in relation to standard CPB (crystalloid priming), in adult patients.
Sixty-two patients were randomly allocated to two groups: 1) Group RAP (n = 27) of patients operated using the RAP and; 2) Control group of patients operated using CPB standard crystalloid method (n = 35). The RAP was performed by draining crystalloid prime from the arterial and venous lines, before CPB, into a collect recycling bag. The main parameters analyzed were: 1) CPB hemodynamic data; 2) Hematocrit and hemoglobin values; 3) The need for blood transfusions.
It was observed statistically significant fewer transfusions during surgery and reduced CPB hemodilution using RAP. The CPB hemodynamic values were similar, observing a tendency to use lower CPB flows in the RAP group patients.
This investigation was designed to be a small-scale pilot study to evaluate the effects of RAP, which were demonstrated concerning the CPB hemodilution and blood transfusions.
The hypothesis was tested whether retrograde autologous priming (RAP) of the cardiopulmonary bypass system, compared to a standard primed system (NON-RAP group), results in less haemodilution and less transfusion of packed red blood cells. Retrospectively, data was collected from the medical charts of one hundred patients undergoing elective coronary artery bypass grafting using cardiopulmonary bypass. Fifty patients where RAP was used have been compared to fifty patients using NON-RAP. The prime volume in the NON-RAP group was 1,627±108 mL versus 782±96 mL in the RAP group (p<0.001). The lowest haematocrit during perfusion was 22% in the NON-RAP group versus 26% when the RAP technique was used (p<0.001). In the NON-RAP group, 26% of the patients received packed red cells in contrast to 6% in the RAP group (p<0.012). A positive association was found between RAP and less transfusion of packed red blood cells (p<0.012). In conclusion, retrograde autologous priming, reducing the prime volume of the cardiopulmonary bypass system, causes less haemodilution and reduces intraoperative transfusion of packed red blood cells.
Practice guidelines reflect published literature. Because of the ever changing literature base, it is necessary to update and revise guideline recommendations from time to time. The Society of Thoracic Surgeons recommends review and possible update of previously published guidelines at least every three years. This summary is an update of the blood conservation guideline published in 2007.
The search methods used in the current version differ compared to the previously published guideline. Literature searches were conducted using standardized MeSH terms from the National Library of Medicine PUBMED database list of search terms. The following terms comprised the standard baseline search terms for all topics and were connected with the logical 'OR' connector--Extracorporeal circulation (MeSH number E04.292), cardiovascular surgical procedures (MeSH number E04.100), and vascular diseases (MeSH number C14.907). Use of these broad search terms allowed specific topics to be added to the search with the logical 'AND' connector.
In this 2011 guideline update, areas of major revision include: 1) management of dual anti-platelet therapy before operation, 2) use of drugs that augment red blood cell volume or limit blood loss, 3) use of blood derivatives including fresh frozen plasma, Factor XIII, leukoreduced red blood cells, platelet plasmapheresis, recombinant Factor VII, antithrombin III, and Factor IX concentrates, 4) changes in management of blood salvage, 5) use of minimally invasive procedures to limit perioperative bleeding and blood transfusion, 6) recommendations for blood conservation related to extracorporeal membrane oxygenation and cardiopulmonary perfusion, 7) use of topical hemostatic agents, and 8) new insights into the value of team interventions in blood management.
Much has changed since the previously published 2007 STS blood management guidelines and this document contains new and revised recommendations.
Objectives:
Surgery of thoracic aortic aneurysm (TAA) is associated with blood loss and coagulopathy and a high need for red blood cell (RBC) volume. Retrograde autologous priming (RAP) decreases haemodilution during cardiopulmonary bypass (CPB). The aim of this study was to show the effect of RAP during surgery of TAA repair on haemodilution, the need for RBC transfusion and the postoperative course compared to conventional CPB (cCPB).
Methods:
A retrospective study was performed on 120 patients with TAA. Half of these patients underwent cCPB and the other half received RAP. Statistical analysis was performed using IBM SPSS statistics 23. The χ2 test, the Fisher's exact tests, the independent t-test and the Mann-Whitney U-test were used. Statistical significance was assumed at P-value <0.05.
Results:
Lower blood product requirements were observed for the RAP group regarding the transfusion of intraoperative RBC (0.87 ± 1.33 vs 1.97 ± 2.43, P = 0.013), postoperative RBC (0.57 ± 1.4 vs 1.32 ± 1.82, P = 0.002) and postoperative fresh frozen plasma (0.52 ± 1.63 vs 1.48 ± 3.32, P = 0.036). The postoperative drainage loss showed significantly lower measurements for the RAP group after 6 h (295.9 ± 342.6 vs 490.6 ± 414.4 ml, P ≤ 0.001), 12 h (450.1 ± 415.5 vs 652.1 ± 463.9 ml, P < 0.001) and 24 h (693.1 ± 483.9 vs 866.4 ± 508.4 ml, P = 0.004).
Conclusions:
RAP is a safe and easy method to reduce RBC transfusion in TAA surgery without any adverse effects on the clinical outcome. We were also able to show beneficial effects on fresh frozen plasma requirements and postoperative chest drainage volume. Furthermore, improved microcirculation can be suspected. In consequence, we have implemented RAP as a clinical standard during thoracic aortic surgery.
This randomized, double-blind study evaluated the short-term effects and safety of perioperative retrograde autologous priming (RAP) for cardiopulmonary bypass (CPB) in patients with cardiac replacement surgery to determine if this approach is a better substitute for crystal liquids priming in patients with valvular heart disease. We observed that RAP significantly decreased the actual priming volume, preserved the hematocrit and hemoglobin level during CPB to a certain degree, and decreased lactate accumulation in CPB period. Moreover, RAP lowered the volume of transfusion and dosage blood products. Thus, our results showed that RAP approach effectively improved tissue perfusion and lowered intraoperative Lac levels, by reducing the hemodilution, which safely and reliably improve the microcirculation perfusion.
Background During the last decades many efforts have been made to reduce transfusion requirements and adverse clinical effects during cardiopulmonary bypass (CPB). The minimal extracorporeal circulation (MECC) system and the technique of retrograde autologous priming (RAP) of a conventional CPB circuit have been associated with decreased hemodilution. Our study aimed to compare conventional CPB (cCPB), RAP, and the ROCsafe MECC (Terumo Europe N.V., Leuven, Belgium) system in elective coronary artery bypass patients. Patients and Methods Data were retrospectively collected on three cohorts of 30 adult CPB patients. Patients were operated using cCPB, RAP, and the ROCsafe MECC system. Results The three groups were comparable in demographic data. The priming volume in the ROCsafe and RAP group was significantly less compared with the conventional priming group (p <0.05). The mean time of extracorporeal circulation and aortic cross-clamp time (p <0.05) were significantly shorter in the ROCsafe group. The levels of hemoglobin (Hb) and hematocrit (Hct) during CPB and postoperatively showed significant differences between the three groups (p < 0.05) and resulted in significantly higher blood transfusion requirements (p < 0.05). Lactate, serum creatinine, troponin, and creatine kinase-myocardial band (CK-MB) levels did not differ significantly among the three groups (p >0.05). There was also no statistically significant difference in ventilation time, intensive care unit (ICU) stay, overall hospital stay, and postoperative complications (p >0.05). Conclusion In conclusion, RAP is compared with cCPB and MECC a safe and low-cost technique in reducing the priming volume of the CPB system, causes less hemodilution, and reduces the need for intra- and postoperative blood transfusion.
Georg Thieme Verlag KG Stuttgart · New York.
Cardiopulmonary bypass can result in hemodilution due to the crystalloid prime, increasing the need for blood transfusion. Alternative perfusion techniques have the potential to decrease this hemodilution. The objective of this study was to determine whether a protocol of retrograde autologous prime (RAP) and venous antegrade prime (VAP) reduces the need for blood transfusion and increases the hematocrit following cardiac surgery.
We performed a retrospective review of 140 consecutive non-randomized patients who underwent cardiac surgery with cardiopulmonary bypass between November 2011 and September 2012. RAP and VAP techniques were used in 70 patients while the other 70 were managed with conventional perfusion strategies. The primary outcome measure was a composite outcome of any blood transfusion or a discharge hematocrit less than 27%.
Baseline demographics and patient characteristics were similar between the two groups, with the exception of the RAP/VAP group having a lower baseline creatinine. There was a trend toward decreased perioperative blood transfusions in the RAP/VAP group (13/70, 19%) compared with the non-RAP/VAP group (23/70, 33%, p=0.053). RAP/VAP patients had a significantly higher hematocrit at hospital discharge (30.0 ± 4.3% vs. 28.3 ± 4.1%, p=0.012). The number of patients receiving a transfusion or being discharged with an hematocrit less than 27% was significantly less in the RAP/VAP group (21 vs. 41, p=0.001). This effect persisted on multivariable analysis.
RAP and VAP perfusion techniques may reduce hemodilution, potentially resulting in less blood transfusions and higher postoperative hematocrits. These techniques should be considered in all patients undergoing cardiac surgery with cardiopulmonary bypass.
When hospitalized, patients may undergo procedures for surgery, treatments (e.g., blood transfusions), or for diagnostic purposes (e.g., biopsy). The principal procedure is the procedure performed for definitive treatment. Hospitalizations usually involve multiple procedures, which together constitute the all-listed procedures performed during a hospital stay. Data on inpatient hospital procedures can help hospital administrators, health practitioners, researchers, and others understand how hospital care, including care related to diagnosis and treatment, is currently provided and what changes or consistencies in care delivery have occurred over time. The present Statistical Brief presents 2011 data on the most common all-listed procedures performed during hospital stays in the United States, overall and by patient age. Changes between 1997 and 2011 in the number of stays and in the rate of hospitalizations with these procedures are also presented. All differences between estimates noted in the text are statistically significant at the .001 level or better.
Intraoperative hypotension may contribute to postoperative acute kidney injury (AKI) and myocardial injury, but what blood pressures are unsafe is unclear. The authors evaluated the association between the intraoperative mean arterial pressure (MAP) and the risk of AKI and myocardial injury.
The authors obtained perioperative data for 33,330 noncardiac surgeries at the Cleveland Clinic, Ohio. The authors evaluated the association between intraoperative MAP from less than 55 to 75 mmHg and postoperative AKI and myocardial injury to determine the threshold of MAP where risk is increased. The authors then evaluated the association between the duration below this threshold and their outcomes adjusting for potential confounding variables.
AKI and myocardial injury developed in 2,478 (7.4%) and 770 (2.3%) surgeries, respectively. The MAP threshold where the risk for both outcomes increased was less than 55 mmHg. Compared with never developing a MAP less than 55 mmHg, those with a MAP less than 55 mmHg for 1–5, 6–10, 11–20, and more than 20 min had graded increases in their risk of the two outcomes (AKI: 1.18 [95% CI, 1.06–1.31], 1.19 [1.03–1.39], 1.32 [1.11–1.56], and 1.51 [1.24–1.84], respectively; myocardial injury 1.30 [1.06–1.5], 1.47 [1.13–1.93], 1.79 [1.33–2.39], and 1.82 [1.31–2.55], respectively].
Even short durations of an intraoperative MAP less than 55 mmHg are associated with AKI and myocardial injury. Randomized trials are required to determine whether outcomes improve with interventions that maintain an intraoperative MAP of at least 55 mmHg.
Objective:
Reducing the priming volume is an effective means of decreasing hemodilution and blood transfusion during cardiopulmonary bypass (CPB). The patient's own blood was used to replace the crystalloid in the CPB circuit by retrograde autologous priming (RAP) in order to decrease the priming volume. Therefore, we performed a meta-analysis to investigate whether RAP could reduce blood transfusion and improve clinical outcomes.
Materials and methods:
A comprehensive search was conducted for randomized, controlled trials (RCTs) exploring RAP in PubMed, Embase, The Cochrane Library, Google Scholar and Chinese literature databases (WanFang, WeiPu and CNKI). Clinical parameters and outcomes were focused on the lowest hematocrit (Hct) during CPB, the number of patients transfused blood intraoperatively, the number of patients transfused blood perioperatively, the number of blood units transfused, 24-hour chest tube drainage, hours to extubation, length of ICU stay, and length of hospital stay.
Results:
Ten trials, with a total of 1123 patients, were included. The number of patients transfused blood intraoperatively (RR = 0.39, 95% CI = [0.29, 0.53], p<0.00001, I(2) = 40%) and perioperatively (RR = 0.53, 95% CI = [0.43, 0.66], p<0.00001, I(2) = 0%) and the number of blood units transfused (SMD = -0.53, 95% CI = [-0.73, -0.33], p<0.00001, I(2) = 14%) were all significantly reduced in the RAP group. No differences in the hours to extubation (SMD = -0.11, 95% CI = [-0.33, 0.12], p=0.37, I(2) = 0%) and the length of ICU stay (SMD = -0.17, 95% CI = [-0.41, 0.08], p=0.18, I(2) = 0%) were observed between the two groups.
Conclusion:
Compared to conventional priming, RAP could reduce transfusion in adults significantly, but had no effect on clinical outcomes, comparing to conventional priming. Further studies involving RAP are expected to investigate if this technique is beneficial to the patient.
Mean arterial blood pressure (MAP) targets are empirically chosen during cardiopulmonary bypass (CPB). We have previously shown that near-infrared spectroscopy (NIRS) can be used clinically for monitoring cerebral blood flow autoregulation. The hypothesis of this study was that real-time autoregulation monitoring using NIRS-based methods is more accurate for delineating the MAP at the lower limit of autoregulation (LLA) during CPB than empiric determinations based on age, preoperative history, and preoperative blood pressure.
Two hundred thirty-two patients undergoing coronary artery bypass graft and/or valve surgery with CPB underwent transcranial Doppler monitoring of the middle cerebral arteries and NIRS monitoring. A continuous, moving Pearson correlation coefficient was calculated between MAP and cerebral blood flow velocity and between MAP and NIRS data to generate mean velocity index and cerebral oximeter index. When autoregulated, there is no correlation between cerebral blood flow and MAP (i.e., mean velocity and cerebral oximetry indices approach 0); when MAP is below the LLA, mean velocity and cerebral oximetry indices approach 1. The LLA was defined as the MAP at which mean velocity index increased with declining MAP to ≥ 0.4. Linear regression was performed to assess the relation between preoperative systolic blood pressure, MAP, MAP in 10% decrements from baseline, and average cerebral oximetry index with MAP at the LLA.
The MAP at the LLA was 66 mm Hg (95% prediction interval, 43 to 90 mm Hg) for the 225 patients in which this limit was observed. There was no relationship between preoperative MAP and the LLA (P = 0.829) after adjusting for age, gender, prior stroke, diabetes, and hypertension, but a cerebral oximetry index value of >0.5 was associated with the LLA (P = 0.022). The LLA could be identified with cerebral oximetry index in 219 (94.4%) patients. The mean difference in the LLA for mean velocity index versus cerebral oximetry index was -0.2 ± 10.2 mm Hg (95% CI, -1.5 to 1.2 mm Hg). Preoperative systolic blood pressure was associated with a higher LLA (P = 0.046) but only for those with systolic blood pressure ≤ 160 mm Hg.
There is a wide range of MAP at the LLA in patients during CPB, making estimation of this target difficult. Real-time monitoring of autoregulation with cerebral oximetry index may provide a more rational means for individualizing MAP during CPB.
The aim of this study was to investigate the effect of retrograde autologous priming (RAP) of the cardiopulmonary bypass (CPB) circuit on cerebral oxygenation.
A retrospective cohort study.
A university hospital.
Ninety-four patients undergoing CPB.
CPB was primed with a RAP technique in the RAP group (n = 46) or with a conventional technique in the control group (n = 48).
Cerebral oxygenation was monitored by measuring the regional cerebral oxygen saturation (rSO(2)). The rSO(2) and Hct values were compared between the groups during surgery. During the CPB period, the RAP group showed significantly higher values for rSO(2) (%) (immediately after the onset of CPB: 51.3 ± 8.4 and 56.3 ± 8.3; 30 minutes after the onset of CPB: 56.3 ± 5.1 and 59.7 ± 7.0; control group and RAP groups, respectively; p < 0.01 for each) and Hct (%) (immediately after the onset of CPB: 21.1 ± 3.7 and 23.1 ± 3.3; 30 minutes after the onset of CPB: 21.9 ± 3.7 and 23.3 ± 2.3; control group and RAP group, respectively; p < 0.02 for each). However, the 2 groups did not differ in rSO(2) (%) (67.2 ± 6.3 and 67.8 ± 6.4) or Hct (%) (27.8 ± 4.1 and 28.9 ± 3.6, control group and RAP group, respectively) at the end of the surgery.
The application of RAP to CPB limits the degree of hemodilution and improves cerebral oxygenation during CPB. The present findings suggest a potential benefit of RAP from a neurologic aspect.
Haemodilution resulting from crystalloid priming of the cardiopulmonary bypass (CPB) circuit is one of the important reasons for blood transfusion in cardiac surgery, especially in patients with low body surface area (BSA). A prospective study was performed to investigate the technique of intraoperative blood donation (IAD) and retrograde autogous priming (RAP) to limit haemodilution and transfusion requirements. Forty patients with low BSA (<1.7m2) undergoing primary valvular cardiac surgery were assigned to either RAP group or a control group (C). The RAP group (n=20) was subjected to IAD by collecting a calculated volume of blood (272+/-44.3 mL) after induction of anaesthesia. Prior to initiation of CPB the prime volume was reduced by discarding some of it and the CPB reservoir was filled retrogradely through the aortic cannula draining 482+/-78.4 mL of blood. In group C (n=20) only IAD was carried out collecting 295.0+/-62.6 mL of blood. Anaesthetic technique was similar in both groups. Strict transfusion thresholds were observed. There were no significant difference between the groups with respect to baseline characteristics, BSA, type of procedure, perfusion technique and haematologic profile. The haematocrit on CPB was significantly higher in the RAP group as compared with group C (24.2+/-1.3% and 22.1+/-2.5% respectively, p=0.009). Transfusion of allogenic blood during and after surgery was significantly lower in the RAP group (143.6+/-117mL) versus 405.2+/-358.1mL in group C (p=0.02). Postoperative chest tube drainage was 218+/-67.4 mL in the RAP group and 300+/-191 mL in group C which was not significantly different (p=0.18). The technique of intraoperative autologous donation and retrograde priming is simple, safe and cost effective procedure for blood conservation in patients with small BSA undergoing primary valvular surgery.
Extreme haemodilution occurring with cardiopulmonary bypass imposes a primary risk factor for blood transfusion in small adult cardiac surgical patients. Priming of the cardiopulmonary bypass circuit with patients' own blood [retrograde autologous priming (RAP)] is a technique used to limit haemodilution and reduce transfusion requirements. We designed this study to evaluate the effects of RAP on reducing perioperative blood transfusion in small adults.
One hundred and twenty patients with a body surface area of less than 1.5 m undergoing first-time, nonemergency cardiac surgery were randomized to either the standard priming group or the RAP group. All patients followed strict transfusion criteria. Homologous transfusion, haematocrit, plasma colloid osmotic pressure and postoperative clinical outcomes were evaluated perioperatively.
Patient characteristics and operative parameters were equal for patients in both groups. With autologous priming, a mean volume of 614.8 +/- 138.8 ml of priming solution was replaced with autologous blood. This allowed a significantly higher haematocrit value during cardiopulmonary bypass (P < 0.05). Red blood cell transfusion was necessary in 83.3% of patients of the standard priming group on pump, whereas only 26.7% of patients of the RAP group required transfusion (P < 0.01). The overall transfusion rate of the RAP group was significantly less than that in the standard priming group during the hospitalization (90.0 vs. 50.0%, P < 0.01). Amongst patients who received transfusion on pump, the number of homologous units of packed red blood cells was less in the RAP group than that in the standard priming group intraoperatively and perioperatively (0.94 +/- 0.32 vs. 1.48 +/- 0.68 units, P = 0.03; 1.24 +/- 0.54 vs. 1.69 +/- 0.69 units, P = 0.15). Ten minutes after aortic cross-clamp, colloid osmotic pressure was reduced by 39.7 +/- 2.8% in the standard priming group and by 28.6 +/- 3.2% in the RAP group (P < 0.05). Clinical outcomes were similar with respect to pulmonary, renal and hepatic function, length of ICU stay and hospital stay.
RAP resulted in a significant decrease in intraoperative haemodilution and conserved the use of blood. This technique should be considered for patients with a small body surface area (<1.5 m) undergoing open heart surgery.
A literature review and meta-analysis were undertaken to assess the clinical effectiveness of retrograde autologous priming of the cardiopulmonary bypass circuit to reduce allogeneic packed red blood transfusions in adult cardiac surgery. Structured searches of Medline, Embase, Cochrane Collaboration Library, Scopus, Cumulative Index to Nursing and Allied Health Literature and Science Direct were performed to identify randomized trials comparing retrograde autologous priming to a prospective control group. A total of 21,643 studies were identified and eighteen trials were retrieved for full-text review. Six trials met eligibility criteria. Pooled estimates demonstrated that retrograde autologous priming significantly reduced the number of patients receiving intraoperative packed red cell transfusions (OR=0.36; 95% CI: 0.13, 0.94; P=0.04, I(2)=47.5%), total hospital stay packed red cell transfusions (OR=0.26; 95% CI: 0.13, 0.52; P=0.0001, I(2)=0%), and the number of units transfused of total hospital stay packed red blood cells (WMD=-0.60; 95% CI: -0.90, -0.31; P=0.0001, I(2)=0%). Retrograde autologous priming, however, did not provide a clinical benefit in reducing the number of units transfused of intraoperative packed red blood cells (WMD=-0.29; 95% CI: -0.59, 0.01; P=0.05). The combined patient population studied in the six trials was mainly primary isolated coronary artery bypass surgery. Assessing the safety of retrograde autologous priming was not possible due to limited data.
The obligatory hemodilution resulting from crystalloid priming of the cardiopulmonary bypass circuit represents a major risk factor for blood transfusion in cardiac operations. We therefore examined whether retrograde autologous priming of the bypass circuit would result in decreased hemodilution and red cell transfusion.
Sixty patients having first-time coronary bypass were prospectively randomized to cardiopulmonary bypass with or without retrograde autologous priming. Retrograde autologous priming was performed at the start of bypass by draining crystalloid prime from the arterial and venous lines into a recirculation bag (mean volume withdrawal: 880 +/- 150 ml). Perfusion and anesthetic techniques were otherwise identical for the two groups. The hematocrit value was maintained at a minimum of 16% and 23% during and after cardiopulmonary bypass, respectively, in all patients. Patients were well matched for all preoperative variables, including established transfusion risk factors. Subsequent hemodynamic parameters, pressor requirements, and fluid requirements were equivalent in the two groups.
The lowest hematocrit value during cardiopulmonary bypass was 22% +/- 3% versus 20% +/- 3% in patients subjected to retrograde autologous priming and in control patients, respectively (p = 0.002). One (3%) of 30 patients subjected to retrograde autologous priming had intraoperative transfusion, and seven (23%) of 30 control patients required transfusion during the operation (p = 0.03). The number of patients receiving any homologous red cell transfusions in the two groups during the entire hospitalization was eight of 30 (27%; retrograde autologous priming) versus 16 of 30 (53%; control) (p = 0.03).
These data suggest that retrograde autologous priming is a safe and effective means of significantly decreasing hemodilution and the number of patients requiring red cell transfusion during cardiac operations.
Hemodilution during cardiopulmonary bypass may lead to anemia requiring intraoperative transfusions. Prime removal from the cardiopulmonary bypass circuit was used to limit dilution and intraoperative transfusions.
The technique of prime removal consists of arterial and then venous side evacuation of crystalloid prior to cardiopulmonary bypass. The effectiveness of this technique, to maintain a higher hematocrit and reduce intraoperative transfusions, was studied prospectively in two consecutive groups of patients undergoing coronary revascularization (controls versus primeless).
Intraoperative hematocrits were significantly higher (P < 0.0001) and transfusions lower (4%) in the primeless versus the control group (19%) (P = 0.003). Prime removal is of particular benefit in anemic (hematocrit < or = 35%) and/or small patients (body surface area < or = 2 m2).
The technique of prime removal is simple, safe and cost-effective, reducing intraoperative transfusions, especially in small and/or anemic patients. It could be part of blood conservation strategies in most adult cardiac operations.
Hemodilution occurring with cardiopulmonary bypass imposes a risk for blood transfusion. Autologous priming of the cardiopulmonary bypass circuit at the initiation of bypass partially replaces the priming solution with autologous blood. We examined the efficacy of autologous priming of the circuit in reducing blood transfusion.
One hundred and four patients were entered into a prospective, randomized, controlled study. Initiation of cardiopulmonary bypass was with or without autologous priming.
With autologous priming, a mean volume of 808.8 +/- 159.3 mL of priming solution was replaced with autologous blood. This allowed a higher hematocrit value on admission to the intensive care unit and at discharge from hospital. In all, 49% of the control group required a blood transfusion compared with 17% from the autologous priming group (p = 0.0007). The mean volume of blood transfused was 277.6 +/- 363.8 mL in the control group compared with 70.1 +/- 173.5 mL in the autologous priming group (p = 0.0005).
Retrograde autologous priming of the bypass circuit reduces homologous blood transfusion owing to the reduction in bypass circuit priming volume.
Unlabelled:
Hemodilution during cardiopulmonary bypass (CPB) is a primary risk factor for blood transfusion in cardiac surgical patients. Priming of the CPB circuit with the patients' own blood (retrograde autologous priming, RAP) is a technique used to limit hemodilution and reduce transfusion requirements. We designed this study to examine the impact of RAP on perioperative blood product use. Using a retrospective cohort study design, the medical records of all patients undergoing CPB (excluding circulatory arrest cases) by a single surgeon were examined. Data were collected over a 24-mo period when RAP was routinely used as a blood conservation strategy (RAP group, n = 257). This group was compared with a cohort of patients during the 24 mo immediately preceding the introduction of RAP into clinical practice (no RAP group, n = 288). A small, statistically insignificant reduction in the percentage of patients receiving packed red blood cells was observed in the RAP group (44% versus 51% no RAP, P = 0.083). No differences were found between the groups in the number of units of packed red blood cells, platelets, or fresh frozen plasma transfused throughout the perioperative period. These results suggest that overall, RAP does not offer a clinically important benefit as a blood conservation technique.
Implications:
Priming of the cardiopulmonary bypass circuit with the patients' own blood (retrograde autologous priming) resulted in insignificant reductions in blood use in a large, unselected group of patients undergoing cardiac surgical procedures.
Previous studies have shown that minimizing the amount of hemodilution during open-heart surgery reduces the need for a blood transfusion. Transfusion increases a patient's medical risks and leads to increased costs. We used a shortened bypass circuit, primed with autologous blood in a retrograde fashion, to decrease red cell transfusion in high-risk patients. One hundred twenty-three patients having first-time, nonemergent coronary artery surgery were chosen for this trial, based on their low prebypass hematocrit and weight. In seventy-two cases, we used a shortened bypass circuit and retrograde autologous prime. A historical control group of fifty-one patients received a standard bypass circuit and prime method. The prebypass hematocrit was 35 +/- 2.62% and 34 +/- 2.99% in the control and study groups, respectively. Red blood cell transfusion was necessary in 70% of the control group during their hospital stay, whereas only 51.4% of the study group required transfusion (p = .006). Patients receiving no blood products were significantly higher in the study group, 48.6% vs. 30.0% (p = .005). The postbypass hematocrit was similar at 26.5 +/- 1.82% vs. 25.5 +/- 2.38%, and the discharge hematocrit was 30.8 +/- 3.33% and 31.2 +/- 3.04% in the control and study groups. respectively. Minimizing hemodilution by shortening the bypass circuit and performing retrograde autologous prime conserves the use of blood during routine coronary artery bypass surgery. These methods can be used for patients who are at greater risk for transfusion.
Evaluate the feasibility and clinical significance of crystalloid prime reduction during the initiation of cardiopulmonary bypass (CPB) using a modified bridge on the cardioplegia delivery system.
Prospective trial of crystalloid prime reduction using a standard Duraflow-coated CPB circuit and Vanguard 2:1 cardio plegia delivery system. Standard prime volume was 1500 cc of Plasmalyte. Prime was reduced via the bridge in the cardioplegia system during initiation of CPB. Packed red blood cells (PRBC) were transfused for hematocrit (Hct) less than 24% while rewarming. A hemoconcentrator was used if the patient's circulating blood volume exceeded 150% of calculated. All data were prospectively collected.
Two hundred and twenty-two consecutive patients undergoing cardiac surgery utilizing CPB were evaluated. There were 107 patients with normal prime volume (NPV) and 115 patients with reduced prime volume (RPV). There was no significant difference in sex, mean age, weight, body surface area (BSA), pre-op Hct, procedure time or procedure between the two groups. There was no difference in total crystalloids infused by the anesthetists (average NPV 1205 cc versus RPV 1148 cc). The average RPV was 622 cc (range 400-1100 cc) or a 59% reduction. Post-op Hct revealed no difference (NPV 28% versus RPV 29%). There was a 24% reduction in patients requiring PRBC (NPV n=23 versus RPV n=18). The use of hemoconcentrators was reduced by 49% (NPV n=18 versus RPV n =11). The average urine output for both groups exceeded 100 cc/hour while on CPB.
Using a modified cardioplegia delivery system is a safe and effective method of CPB prime reduction. A RPV resulted in fewer patients requiring PRBC transfusions and fewer hemoconcentrators used. Based on our experience, we would recommend attempting to reduce prime volume in all patients undergoing CPB.
Retrograde autologous priming reduces transfusion requirements during CPB
- S A Ancheri
- S V Rao
Ancheri SA, Rao SV. Retrograde autologous priming
reduces transfusion requirements during CPB. Indian J Appl
Res. 2016;6:20-24.