Indications for red blood cell transfusion in cardiac surgery: a systematic review and meta-analysis

Comparison of liberal versus restrictive transfusion strategies after hip surgery in patients with coronary artery disease: a post hoc analysis of the FOCUS trial

BACKGROUND

There are no clear recommendations for optimal transfusion thresholds for patients with coronary artery disease who undergo noncardiac surgery. By comparing restrictive and liberal transfusion strategies for coronary artery disease combined with hip surgery, this study hopes to provide recommendations for transfusion strategies in this special population.

METHODS

A total of 805 patients from the FOCUS trial (Transfusion Trigger Trial for Functional Outcomes in Cardiovascular Patients Undergoing Surgical Hip Fracture Repair) with coronary artery disease combined with hip surgery were divided into two groups based on transfusion thresholds: restricted transfusion (a hemoglobin level of 8 g/deciliter) and liberal transfusion (a hemoglobin threshold of 10 g/deciliter). The primary outcome of this study was a composite endpoint including in-hospital death, myocardial infarction, unstable angina, and acute heart failure. The secondary endpoints included other in-hospital adverse events and 30- and 60-day follow-up events. Analyses were performed by intention to treat.

RESULTS

Except for the proportion of congestive heart failure patients, the baseline levels of the two groups were comparable. The median number of transfusion units in the liberal transfusion group was 2 units, and the median transfusion volume in the restricted transfusion group was 0 units. The primary outcome was not significantly different between the two groups (9.2% vs. 9.4%, p = 0.91). The incidence of in-hospital myocardial infarction events was lower in the liberal transfusion group than in the restricted transfusion group (3.2% vs. 6.2%) (OR = 0.51, P = 0.048). The remaining in-hospital endpoint events, except for myocardial infarction, were not significantly different between the two groups. The 30-day and 60-day endpoints of death and inability to walk independently were not significantly different between the two groups, with ORs (95% CI) of 1.00 (0.75-1.31) and 1.06 (0.80-1.41), respectively. We also found no interaction between transfusion strategies and factors such as age, sex, or multiple underlying comorbidities at the 60-day follow-up.

CONCLUSIONS

There was no significant difference in the in-hospital, 30-day or 60-day outcome endpoints between the two groups. However, this study demonstrated that a liberal transfusion strategy tends to reduce the incidence of in-hospital myocardial infarction events in patients with coronary artery disease combined with hip surgery compared to a restrictive transfusion strategy. More high-quality studies should be designed to investigate the optimal transfusion threshold in patients with coronary artery disease treated without cardiac surgery.

Efficacy and safety of restrictive versus liberal blood transfusion strategies in acute myocardial infarction and anemia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Blood transfusion strategies in patients with acute myocardial infarction (AMI) and anemia are yet to be conclusively identified. Thus, we aim to assess the efficacy and safety of restrictive versus liberal blood transfusion strategies for AMI and anemia.

METHODS

A systematic review and meta-analysis of randomized controlled trials (RCTs) retrieved from PubMed, web of science, SCOPUS, EMBASE, and Cochrane Central Register of Controlled Trials were performed through November 2023. We used RevMan V. 5.4 to pool dichotomous data using risk ratio (RR) and continuous data using mean difference (MD) with a 95% confidence interval (CI). (PROSPERO): ID: CRD42023490692.

RESULTS

We included four RCTs with 4.325 patients. There was no significant difference between both groups regarding MACE whether at 30 days (RR: 0.93 with 95% CI [0.57-1.51], P  = 0.76) or ≥ six months (RR: 1.17 with 95% CI [0.95-1.45], P  = 0.14), all-cause mortality at 30 days (RR: 1.16 with 95% CI [0.95-1.40], P  = 0.14) or ≥ six months (RR: 1.16 with 95% CI [0.88-1.53], P  = 0.28). However, the liberal strategy was significantly associated with increased hemoglobin level change (MD: -1.44 with 95% CI [-1.68 to -1.20], P  < 0.00001). However, the restrictive strategy was significantly associated with a lower incidence of acute lung injury (RR: 0.11 with 95% CI [0.02-0.60], P  = 0.01).

CONCLUSION

There was no significant difference between the restrictive blood transfusion strategy and the liberal blood transfusion strategy regarding the clinical outcomes. However, restrictive blood transfusion strategy was significantly associated with a lower incidence of acute lung injury than liberal blood transfusion strategy.

The Adherence to an Intraoperative Blood Product Transfusion Algorithm Is Associated With Reduced Blood Product Transfusions in Cardiac Surgical Patients Undergoing Coronary Artery Bypass Grafts and Aortic and/or Valve Replacement Surgery: A Single-Center, Observational Study

OBJECTIVE

To demonstrate the value of a viscoelastic-based intraoperative transfusion algorithm to reduce non-RBC product administration in adult cardiac surgical patients.

DESIGN

A prospective observational study.

SETTING

At a quaternary academic teaching hospital.

PARTICIPANTS

Cardiac surgical patients.

INTERVENTIONS

Viscoelastic-based intraoperative transfusion algorithm.

MEASUREMENTS AND MAIN RESULTS

The study authors compared intraoperative blood product transfusion rates in 184 cardiac surgical patients to 236 historic controls after implementing a viscoelastic-based algorithm. The authors found a non-significant reduction in transfusion of 23.8% for fresh frozen plasma (FFP) units (0.84 ± 1.4 v 0.64 ± 1.38; p = ns), 33.4% for platelet units (0.90 ± 1.39 v 0.60 ± 131; p = ns), and 15.8% for cryoprecipitate units (0.19 ± 0.54 v 0.16 ± 0.50; p = ns). They found a 43.9% reduction in red blood cell (RBC) units transfused (1.98 ± 2.24 v 0.55 ± 1.36; p = 0.008). There were no statistically significant differences in time to extubation (8.0 hours (4.0-21.0) v 8.0 (4.0-22.3), reoperation for bleeding (15 [12.3%] v 10 [10.6%]), intensive care unit length of stay (ICU LOS) (51.0 hours [28.0-100.5] v 53.5 [33.3-99.0]) or hospital LOS (9.0 days [6.0-15.0] v 10.0 [7.0-17.0]). Deviation from algorithm adherence was 32.7% (48/147). Packed RBC, FFP, platelets, cryoprecipitate, and cell saver were significantly reduced in the Algorithm Compliant Cohort compared with historic controls, whereas times to extubation, ICU LOS, and hospital LOS did not reach significance.

CONCLUSIONS

After the implementation of a viscoelastic-based algorithm, patients received fewer packed RBC, FFP, platelets, cryoprecipitate, and cell saver. Algorithm-compliant patients received fewer transfusions; however, reductions in times to extubation, ICU LOS, and hospital LOS were not statistically significant compared with historic controls.

Red Blood Cell Transfusion and Pulmonary Complications: The Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis

BACKGROUND

Intraoperative packed red blood cell (PRBC) transfusion during cardiac surgery is associated with increased postoperative morbidity and mortality; however, data on the association between PRBC transfusion and postoperative pulmonary complications (PPCs) are somewhat conflicting. Using The Society of Thoracic Surgeons Adult Cardiac Surgery Database, we sought to determine whether intraoperative PRBC transfusion was associated with PPCs as well as with longer intensive care unit (ICU) stay after isolated coronary artery bypass grafting (CABG) surgery.

METHODS

A registry-based cohort study was performed on 751,893 patients with isolated CABG between January 1, 2015, to December 31, 2019. Using propensity score-weighted regression analysis, we analyzed the effect of intraoperative PRBC on the incidence of PPCs (hospital-acquired pneumonia [HAP], mechanical ventilation for >24 hours, or reintubation), ICU length of stay, and ICU readmission.

RESULTS

Transfusion of 1, 2, 3, and ≥4 units of PRBCs was associated with increased odds for HAP (odds ratios [ORs], 1.24 [95% CI, 1.21-1.26], 1.28 [95% CI, 1.26-1.32], 1.36 [95% CI, 1.33-1.39], 1.31 [95% CI, 1.28-1.34]), reintubation (ORs, 1.23 [95% CI, 1.21-1.25], 1.38 [95% CI, 1.35-1.40], 1.57 [95% CI, 1.55-1.60], 1.70 [95% CI, 1.67-1.73]), prolonged ventilation (ORs, 1.34 [95% CI, 1.33-1.36], 1.56 [95% CI, 1.53-1.58], 1.97 [95% CI, 1.94-2.00], 2.27 [95% CI, 2.24-2.30]), initial ICU length of stay (mean difference in hours, 6.79 [95% CI, 6.00-7.58], 9.55 [95% CI, 8.71-10.38], 17.26 [95% CI, 16.38-18.15], 22.14 [95% CI, 21.22-23.06]), readmission to ICU (ORs, 1.14 [95% CI, 1.12-1.64], 1.15 [95% CI, 1.12-1.17], 1.15 [95% CI, 1.13-1.18], 1.32 [95% CI, 1.29-1.35]), and additional ICU length of stay (mean difference in hours, 0.55 [95% CI, 0.18-0.92], 0.38 [95% CI, 0.00-0.77], 1.02 [95% CI, 0.61-1.43], 1.83 [95% CI, 1.40-2.26]), respectively.

CONCLUSIONS

Intraoperative PRBC transfusion was associated with increased incidence of PPCs, prolonged ICU stay, and ICU readmissions after isolated CABG surgery.

Effect of blood conservation protocol on the utilisation of blood and outcome of patients undergoing open heart surgery

INTRODUCTION

Cardiac surgery is fraught with increased consumption of blood and blood products. Various strategies for blood conservation have been described. Our aim was to study the impact of a structured blood conservation protocol (BCP) on the utilization of blood and patient outcome.

METHODS

Retrospective analysis of prospectively collected data comparing adult patients undergoing open heart surgery with BCP with those undergoing surgery without BCP. The primary objective was to compare the amount of blood utilized and the hematocrit at discharge. The secondary objective was to compare the parameters of patient outcomes. The level of significance was set at 0.05.

RESULTS

The proportion of patients requiring transfusion (19.1% [9/47] vs 58.9% [33/56]; p < 0.001) and the quantity of blood transfused (12 units vs 45 units; p 0.003) in the BCP group was significantly lower. Interestingly, the hematocrit level at discharge was comparable between the groups (30.9 (4.8) versus 31.8 (2.4), p-0.671). The average cost incurred for transfusing blood in the BCP group was ₹ 370.2 as compared to ₹1165.1 in the other (p < 0.001). BCP reduced the odds of overall blood transfusion by 79.8% (OR 0.202 (0.084-0.485); p < 0.001) and intraoperative blood transfusion by 95.3% (OR 0.047 (0.010-0.213); p < 0.001). The morbidity and mortality were comparable between the groups.

CONCLUSION

Implementing a structured blood conservation protocol in patients undergoing open heart surgery significantly reduces the need for blood transfusion. It also has a promising impact on patient recovery after surgery and significant positive cost implications.

Alternative blood transfusion triggers: a narrative review

BACKGROUND

Anemia, characterized by low hemoglobin levels, is a global public health concern. Anemia is an independent factor worsening outcomes in various patient groups. Blood transfusion has been the traditional treatment for anemia; its triggers, primarily based on hemoglobin levels; however, hemoglobin level is not always an ideal trigger for blood transfusion. Additionally, blood transfusion worsens clinical outcomes in certain patient groups. This narrative review explores alternative triggers for red blood cell transfusion and their physiological basis.

MAIN TEXT

The review delves into the physiology of oxygen transport and highlights the limitations of using hemoglobin levels alone as transfusion trigger. The main aim of blood transfusion is to optimize oxygen delivery, necessitating an individualized approach based on clinical signs of anemia and the balance between oxygen delivery and consumption, reflected by the oxygen extraction rate. The narrative review covers different alternative triggers. It presents insights into their diagnostic value and clinical applications, emphasizing the need for personalized transfusion strategies.

CONCLUSION

Anemia and blood transfusion are significant factors affecting patient outcomes. While restrictive transfusion strategies are widely recommended, they may not account for the nuances of specific patient populations. The search for alternative transfusion triggers is essential to tailor transfusion therapy effectively, especially in patients with comorbidities or unique clinical profiles. Investigating alternative triggers not only enhances patient care by identifying more precise indicators but also minimizes transfusion-related risks, optimizes blood product utilization, and ensures availability when needed. Personalized transfusion strategies based on alternative triggers hold the potential to improve outcomes in various clinical scenarios, addressing anemia's complex challenges in healthcare. Further research and evidence are needed to refine these alternative triggers and guide their implementation in clinical practice.

Lack of RBC transfusion independence by Day 30 following allogeneic hematopoietic stem cell transplant strongly predicts inferior survival and high non-relapse mortality in acute myeloid leukemia patients

BACKGROUND

Studies have suggested that acute myeloid leukemia (AML) patients with incomplete hematologic recovery undergoing allogeneic stem cell transplantation (allo-HSCT) had inferior overall survival (OS).

STUDY DESIGN AND METHODS

This single-center, retrospective study of AML patients evaluated the relationship between red blood cell (RBC) and platelet (PLT) transfusion requirements during the first 30 days and long-term outcomes after allo-HSCT through multivariate analyses.

RESULTS

A total of 692 AML patients received peripheral blood stem cells (89.2%), marrow (5.6%), or umbilical cord (5.2%) from matched related (37.4%), unrelated (49.1%), or haploidentical (8.2%) donors in 2011-2017. Transfusion requirements during the first 30 days for RBC (89.5% transfused, median 3, range 1-18 units) or PLT (98.2% transfused, median 6, range 1-144 units) were variable. By Day 30, 56.7% (95% confidence interval [CI]: 52.8-60.3%) and 86.1% (95% CI: 83.2-88.5%) had achieved RBC and PLT transfusion independence, respectively. Median follow-up among survivors (n = 307) was 7.1 years (range: 2.7-11.8). Lack of RBC transfusion independence by Day 30 was strongly and independently associated with worse 5-year OS (39.2% vs. 59.6%, adjusted hazard ratio [HR] 1.83, 95% CI: 1.49-2.25), leukemia-free survival (35.8% vs. 55.5%, HR = 1.75, 95% CI: 1.43-2.14), and NRM (29.7% vs. 13.7%, HR = 2.05, 95% CI: 1.45-2.89) (p < .001). There was no difference in relapse rates among patients who achieved or did not achieve RBC (p = .34) or PLT (p = .64) transfusion independence.

CONCLUSION

Prolonged RBC dependence predicted worse survival and NRM rates, but not increased relapse. Posttransplant surveillance of such patients should be adjusted with more attention to non-relapse complications.

Individualized red-cell transfusion strategy for non-cardiac surgery in adults: a randomized controlled trial

BACKGROUND

Red-cell transfusion is critical for surgery during the peri-operative period; however, the transfusion threshold remains controversial mainly owing to the diversity among patients. The patient's medical status should be evaluated before making a transfusion decision. Herein, we developed an individualized transfusion strategy using the West-China-Liu's Score based on the physiology of oxygen delivery/consumption balance and designed an open-label, multicenter, randomized clinical trial to verify whether it reduced red cell requirement as compared with that associated with restrictive and liberal strategies safely and effectively, providing valid evidence for peri-operative transfusion.

METHODS

Patients aged >14 years undergoing elective non-cardiac surgery with estimated blood loss > 1000 mL or 20% blood volume and hemoglobin concentration <10 g/dL were randomly assigned to an individualized strategy, a restrictive strategy following China's guideline or a liberal strategy with a transfusion threshold of hemoglobin concentration <9.5 g/dL. We evaluated two primary outcomes: the proportion of patients who received red blood cells (superiority test) and a composite of in-hospital complications and all-cause mortality by day 30 (non-inferiority test).

RESULTS

We enrolled 1182 patients: 379, 419, and 384 received individualized, restrictive, and liberal strategies, respectively. Approximately 30.6% (116/379) of patients in the individualized strategy received a red-cell transfusion, less than 62.5% (262/419) in the restrictive strategy (absolute risk difference, 31.92%; 97.5% confidence interval [CI]: 24.42-39.42%; odds ratio, 3.78%; 97.5% CI: 2.70-5.30%; P <0.001), and 89.8% (345/384) in the liberal strategy (absolute risk difference, 59.24%; 97.5% CI: 52.91-65.57%; odds ratio, 20.06; 97.5% CI: 12.74-31.57; P <0.001). No statistically significant differences were found in the composite of in-hospital complications and mortality by day 30 among the three strategies.

CONCLUSION

The individualized red-cell transfusion strategy using the West-China-Liu's Score reduced red-cell transfusion without increasing in-hospital complications and mortality by day 30 when compared with restrictive and liberal strategies in elective non-cardiac surgeries.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01597232.

Coagulation Tests and Bleeding Classification After Cardiopulmonary Bypass: A Prospective Study

OBJECTIVE

No recent prospective studies have analyzed the accuracy of standard coagulation tests and thromboelastography (TEG) to identify patients with excessive microvascular bleeding following cardiopulmonary bypass (CPB). The aim of this study was to assess the value of coagulation profile tests, as well as TEG, for the classification of microvascular bleeding after CPB.

DESIGN

A prospective observational study.

SETTING

At a single-center academic hospital.

PARTICIPANTS

Patients ≥18 years of age undergoing elective cardiac surgery.

INTERVENTIONS

Qualitative assessment of microvascular bleeding post-CPB (surgeon and anesthesiologist consensus) and the association with coagulation profile tests and TEG values.

MEASUREMENTS AND MAIN RESULTS

A total of 816 patients were included in the study-358 (44%) bleeders and 458 (56%) nonbleeders. Accuracy, sensitivity, and specificity for the coagulation profile tests and TEG values ranged from 45% to 72%. The predictive utility was similar across tests, with prothrombin time (PT) (62% accuracy, 51% sensitivity, 70% specificity), international normalized ratio (INR) (62% accuracy, 48% sensitivity, 72% specificity), and platelet count (62% accuracy, 62% sensitivity, 61% specificity) displaying the highest performance. Secondary outcomes were worse in bleeders versus nonbleeders, including higher chest tube drainage, total blood loss, transfusion of red blood cells, reoperation rates (p < 0.001, respectively), readmission within 30 days (p = 0.007), and hospital mortality (p = 0.021).

CONCLUSIONS

Standard coagulation tests and individual components of TEG in isolation agree poorly with the visual classification of microvascular bleeding after CPB. The PT-INR and platelet count performed best but had low accuracy. Further work is warranted to identify better testing strategies to guide perioperative transfusion decisions in cardiac surgical patients.

Timing of Blood Transfusions and 30-Day Patient Outcomes After Coronary Artery Bypass Graft Surgery

OBJECTIVE

Packed red blood cell transfusion during coronary artery bypass graft surgery is known to be associated with adverse outcomes. However, the association of the timing between transfusions in relation to discharge and 30-day postoperative outcomes has not been studied. The study authors investigated the impact of transfusion timing on 30-day surgical outcomes.

DESIGN

A retrospective review.

SETTING

At a single tertiary-care academic hospital.

PARTICIPANTS

A total of 2,481 adult patients underwent primary coronary artery bypass graft surgery between January 2014 and December 2020.

MEASUREMENTS AND MAIN RESULTS

The relationship between the timing of packed red blood cell transfusion (intraoperative, postoperative, or both) and 30-day postoperative outcome variables was calculated as an odds ratio. The influence of timing of transfusion on adjusted probability of postoperative complications was plotted against the lowest intraoperative hematocrit. The median age of the population was 67 years (60.0-74.0), body mass index was 28.5 (25.6-32.3) kg/m², and 497 (20.0%) were female. A total of 1,588 (36%) patients received packed red blood cell transfusions; 182 (7.3%) received intraoperative transfusions, 489 (19.7%) received postoperative transfusions, and 222 (9.0%) received both (intraoperative and postoperative transfusions). Postoperative transfusion was associated with significantly higher odds of readmission (1.83 [1.32-2.54], p = 0.002) and heart failure (1.64 [1.2-2.23], p = 0.008) compared to patients with no transfusions; whereas intraoperative transfusions were not.

CONCLUSION

The authors' data suggested that the postoperative timing of transfusion in patients undergoing coronary artery bypass graft surgery may be associated with an increased incidence of 30-day heart failure and readmission. Prospective research is needed to conclusively confirm these findings.

Modified cardiopulmonary bypass with low priming volume for blood conservation in cardiac valve replacement surgery

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.

An Individualized Red Blood Cell Transfusion Strategy Using Pediatric Perioperative-Transfusion-Trigger Score Reduced Perioperative Blood Exposure for Children: A Randomized Controlled Clinical Trial

Objective

The optimal red blood cell transfusion strategy for children remains unclear. We developed an individualized red blood cell transfusion strategy for children and tested the hypothesis that transfusion guided by this strategy could reduce blood exposure, without increasing perioperative complications in children.

Methods

In this randomized controlled clinical trial, 99 children undergoing noncardiac surgeries who had blood loss of more than 20% total blood volume were randomly assigned to an individualized-strategy group using Pediatric Perioperative-Transfusion-Trigger Score or a control group. The amount of transfused red blood cell was counted, and patients were followed up for postoperative complications within 30 days.

Results

Twenty-six children (53.1%) in the individualized-strategy group received transfusion perioperatively, as compared with 37 children (74%) in the control group (p < 0.05). During surgery, children in the individualized-strategy group were exposed to fewer transfusions than in the control group (0.87±1.03 vs 1.33±1.20 Red-Blood-Cell units per patient, p = 0.02). The incidence of severe complications in the individualized-strategy group had a lower trend compared to the control group (8.2% vs 18%, p = 0.160). No significant difference was found in the other outcomes.

Conclusion

This trial proved that red blood cell transfusion guided by the individualized strategy reduced perioperative blood exposure in children, without increasing the incidence of severe complications. This conclusion needs to be reaffirmed by larger-scale, multicenter clinical trials.

Generating real-world evidence compatible with evidence from randomized controlled trials: a novel observational study design applicable to surgical transfusion research

BACKGROUND

Numerous observational studies have revealed an increased risk of death and complications with transfusion, but this observation has not been confirmed in randomized controlled trials (RCTs). The "transfusion kills patients" paradox persists in real-world observational studies despite application of analytic methods such as propensity-score matching. We propose a new design to address this long-term existing issue, which if left unresolved, will be deleterious to the healthy generation of evidence that supports optimized transfusion practice.

METHODS

In the new design, we stress three aspects for reconciling observational studies and RCTs on transfusion safety: (1) re-definition of the study population according to a stable hemoglobin range (gray zone of transfusion decision; 7.5-9.5 g/dL in this study); (2) selection of comparison groups according to a trigger value (last hemoglobin measurement before transfusion; nadir during hospital stay for control); (3) dealing with patient heterogeneity according to standardized mean difference (SMD) values. We applied the new design to hospitalized older patients (aged ≥60 years) undergoing general surgery at four academic/teaching hospitals. Four datasets were analyzed: a base population before (Base Match-) and after (Base Match+) propensity-score matching to simulate previous observational studies; a study population before (Study Match-) and after (Study Match+) propensity-score matching to demonstrate effects of our design.

RESULTS

Of 6141 older patients, 662 (10.78%) were transfused and showed high heterogeneity compared with those not receiving transfusion, particularly regarding preoperative hemoglobin (mean: 11.0 vs. 13.5 g/dL) and intraoperative bleeding (≥500 mL: 37.9% vs. 2.1%). Patient heterogeneity was reduced with the new design; SMD of the two variables was reduced from approximately 100% (Base Match-) to 0% (Study Match+). Transfusion was related to a higher risk of death and complications in Base Match- (odds ratio [OR], 95% confidence interval [CI]: 2.68, 1.86-3.86) and Base Match+ (2.24, 1.43-3.49), but not in Study Match- (0.77, 0.32-1.86) or Study Match+ (0.66, 0.23-1.89).

CONCLUSIONS

We show how choice of study population and analysis could affect real-world study findings. Our results following the new design are in accordance with relevant RCTs, highlighting its value in accelerating the pace of transfusion evidence generation and generalization.

Stroke, Seizures, Hallucinations and Postoperative Delirium as Neurological Complications after Cardiac Surgery and Percutaneous Valve Replacement

(1) Background: Neurological complications such as acute ischemic stroke or postoperative delirium are frequent after cardiac surgery or percutaneous valve replacement. This study aimed to identify corresponding risk factors. (2) Methods: 297 patients with percutaneous valve replacement or cardiac surgery were postoperatively screened for neurological complications such as delirium, stroke, seizures and hallucinations twice daily for three days. Pre- and perioperative risk factors were evaluated in a multivariate model. (3) Results: Neurological complications occurred in 43.8% (n = 130) as composed of delirium (43.43%, n = 129), stroke (2.7%, n = 8), seizures (1.35%, n = 4) and real hallucinations (3.36%, n = 10). Multiple logistic regression revealed an association of neurological complications with lower Montreal Cognitive Assessment scores (Exp(B) 2.042; 95% CI, 1.183−3.525, p = 0.010), older age (Exp(B) 1.071; 95% CI, 1.036−1.107, p < 0.001), red blood cell transfusions until postoperative day 3 (Exp(B) 1.157; 95% CI, 1.030−1.300, p = 0.014), history of heart failure (Exp(B) 1.985; 95% CI, 1.130−3.487, p = 0.017) and increased CRP levels (Exp(B) 1.004; 95% CI, 1.000−1.008, p = 0.037). (4) Conclusions: Postoperative delirium remains a frequent complication after cardiac surgery, while stroke and seizures occur rarely. A preoperative risk profile including older age, history of heart failure and cognitive impairment was identified for a complicated postoperative course. However, the impact of an intense inflammatory response must not be neglected.

ONTraC: A 20-Year History of a Successfully Coordinated Provincewide Patient Blood Management Program: Lessons Learned and Goals Achieved

Our understanding of the risks associated with perioperative anemia and transfusion, in terms of increased morbidity and mortality, has evolved over the past 2 decades. By contrast, our understanding of the potential mechanisms of injury and optimal treatment strategies remains incomplete. As such, the important role of effective patient blood management (PBM) programs, which address both the effective treatment of anemia and minimizes the need for red blood cell (RBC) transfusion, is of central importance to optimizing patient care and improving patient outcomes. We report on important clinical outcomes of the Ontario Transfusion Coordinator (ONTraC Program), a network of 25 hospital sites, working in coordination over the past 20 years. Transfusion nurse coordinators were assigned to apply multimodal best practice in PBM (including recommended changes in surgical approach; diagnosis, assessment, and treatment of anemia; and adherence to more restrictive RBC transfusion thresholds). Data were collected on various clinical parameters. We further described lessons learned and difficulties encountered in this multisite PBM initiative. A significant reduction in RBC transfusions was observed for numerous indexed surgeries. For example, RBC transfusion rates for knee arthroplasty decreased from 25% in 2002 to 0.4% in 2020. For coronary artery bypass graft (CABG) surgery, transfusion rates decreased from 60% in 2002 to 27% in 2020. We also observed a decrease in RBC units utilized per transfused patient for knee (2.1 ± 0.5 [2002] vs 1.0 ± 0.6 [2020] units per patient) and CABG surgery (3.3 ± 0.6 [2002] vs 2.3 ± 1.9 [2020] units per patient). These reductions were associated with favorable clinical outcomes, including reduced length of hospital stay (P = .00003) and a reduced rate of perioperative infections (P < .001) for nontransfused versus transfused patients. These advances have been achieved with estimated savings in the tens of millions of dollars annually. Our experience and data support the hypothesis that instituting an integrated network of transfusion nurse coordinators can provide an effective provincewide PBM program, reduce RBC transfusions, improve some patient outcomes, and reduce health care costs, as an example of a "win-win-win" medical program.

Perioperative blood transfusion in major abdominal cancer surgery: a multi-centre service evaluation and national survey

Background

Anaemia is associated with complications and death after surgery. Perioperative red-cell transfusion triggers are not well defined in patients having oncological surgery, or with cardiovascular disease.

Methods

We carried out a prospective multicentre cohort study and a clinician survey of UK transfusion practice in adult patients undergoing surgery for abdominal malignancy. The primary outcome was red cell transfusion. Secondary outcomes were transfusion trigger haemoglobin, incidence of complications, length of hospital stay, and acute hospital mortality.

Results

In this prospective cohort study, data were collected on 412 patients undergoing surgery for intrabdominal malignancy in 14 NHS hospitals. Twenty-two (5.2%) patients received preoperative, 42 (10.2%) intraoperative, and 52 (12.2%) postoperative red blood cell transfusion. The mean postoperative transfusion trigger was 75.3 g L-1, and the mean number of units of red blood cells transfused was 1.5 (standard deviation, 1.1). Seventeen (4.0%) patients had a documented postoperative troponin elevation. Five (1.2%) patients died within 30 days of surgery. In the survey, 117 clinicians submitted complete responses, of whom 62 (53%) indicated that a transfusion threshold of 70 g L-1 was appropriate: however, this decreased to six (5.1%) if there was evidence of recent cardiac ischaemia. There were 100 (86%) respondents who indicated equipoise for a trial of restrictive vs liberal transfusion, decreasing to 56% if there was coexisting cardiovascular disease.

Conclusions

Many patients having oncological surgery receive red cell transfusion, the majority being given postoperatively. Restrictive transfusion practice is generally followed; however, variability exists especially in cardiovascular disease. Equipoise exists for a study of transfusion thresholds in this group.

Guidelines on enhanced recovery after cardiac surgery under cardiopulmonary bypass or off-pump

OBJECTIVE

To provide recommendations for enhanced recovery after cardiac surgery (ERACS) based on a multimodal perioperative medicine approach in adult cardiac surgery patients with the aim of improving patient satisfaction, reducing postoperative mortality and morbidity, and reducing the length of hospital stay.

DESIGN

A consensus committee of 20 experts from the French Society of Anaesthesia and Intensive Care Medicine (Société française d'anesthésie et de réanimation, SFAR) and the French Society of Thoracic and Cardiovascular Surgery (Société française de chirurgie thoracique et cardio-vasculaire, SFCTCV) was convened. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. The entire guideline process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide the assessment of the quality of evidence.

METHODS

Six fields were defined: (1) selection of the patient pathway and its information; (2) preoperative management and rehabilitation; (3) anaesthesia and analgesia for cardiac surgery; (4) surgical strategy for cardiac surgery and bypass management; (5) patient blood management; and (6) postoperative enhanced recovery. For each field, the objective of the recommendations was to answer questions formulated according to the PICO model (Population, Intervention, Comparison, Outcome). Based on these questions, an extensive bibliographic search was carried out and analyses were performed using the GRADE approach. The recommendations were formulated according to the GRADE methodology and then voted on by all the experts according to the GRADE grid method.

RESULTS

The SFAR/SFCTCV guideline panel provided 33 recommendations on the management of patients undergoing cardiac surgery under cardiopulmonary bypass or off-pump. After three rounds of voting and several amendments, a strong agreement was reached for the 33 recommendations. Of these recommendations, 10 have a high level of evidence (7 GRADE 1+ and 3 GRADE 1-); 19 have a moderate level of evidence (15 GRADE 2+ and 4 GRADE 2-); and 4 are expert opinions. Finally, no recommendations were provided for 3 questions.

CONCLUSIONS

Strong agreement existed among the experts to provide recommendations to optimise the complete perioperative management of patients undergoing cardiac surgery.

Changes in perioperative red cell transfusion practice over time in patients undergoing surgery for upper gastrointestinal and liver cancer: a retrospective cohort study at a single tertiary centre

OBJECTIVES

Optimum transfusion trigger for adults undergoing cancer surgery is uncertain. Published guidelines recommend restrictive transfusion strategies in hospitalised adults. We aimed to measure the red cell transfusion rate and haemoglobin trigger in patients undergoing cancer surgery and how closely practice reflected published guidelines.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary centre.

PARTICIPANTS

Adult patients undergoing surgery for upper gastrointestinal or liver malignancy.

EXPOSURE

Postguideline change (2015-2017) versus preguideline change (2011-2012).

OUTCOME MEASURES

Primary: transfusion rate, secondary: transfusion trigger. Multivariable logistic regression was used to assess factors and adjust for confounders affecting our outcome measures.

RESULTS

1578 surgical records were identified for 1520 patients. 946/1530 (62%) patients had preoperative anaemia. The transfusion rate decreased from 23% in 2011-2012 to 14% in 2015-2017. This change remained significant after adjusting for other variables associated with transfusion rates. Mean pretransfusion haemoglobin in those who were transfused was 78±13 g/L in 2011-2012 and 80±15 g/L in 2015-2017. This change in haemoglobin transfusion triggers was not significant.

CONCLUSION

Transfusion rate has decreased over the study period in patients undergoing surgery for malignancy and is consistent with a restrictive transfusion strategy.

Impact of restrictive red blood cell transfusion strategy on thrombosis-related events: A meta-analysis and systematic review

BACKGROUND AND OBJECTIVES

There is an ongoing controversy regarding the risks of restrictive and liberal red blood cell (RBC) transfusion strategies. This meta-analysis assessed whether transfusion at a lower threshold was superior to transfusion at a higher threshold, with regard to thrombosis-related events, that is, whether these outcomes can benefit from a restrictive transfusion strategy is debated.

MATERIALS AND METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials and Scopus from inception up to 31 July 2021. We included randomized controlled trials (RCTs) in any clinical setting that evaluated the effects of restrictive versus liberal RBC transfusion in adults. We used random-effects models to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) based on pooled data.

RESULTS

Thirty RCTs involving 17,334 participants were included. The pooled RR for thromboembolic events was 0.65 (95% CI 0.44-0.94; p = 0.020; I²  = 0.0%, very low-quality evidence), favouring the restrictive strategy. There were no significant differences in cerebrovascular accidents (RR = 0.83; 95% CI 0.64-1.09; p = 0.180; I²  = 0.0%, very low-quality evidence) or myocardial infarction (RR = 1.05; 95% CI 0.87-1.26; p = 0.620; I²  = 0.0%, low-quality evidence). Subgroup analyses showed that a restrictive (relative to liberal) strategy reduced (1) thromboembolic events in RCTs conducted in North America and (2) myocardial infarctions in the subgroup of RCTs where the restrictive transfusion threshold was 7 g/dl but not in the 8 g/dl subgroup (with a liberal transfusion threshold of 10 g/dl in both subgroups).

CONCLUSIONS

A restrictive (relative to liberal) transfusion strategy may be effective in reducing venous thrombosis but not arterial thrombosis.

Gelatin and the risk of acute kidney injury after cardiac surgery

BACKGROUND

Gelatin has been used as a plasma volume expander because of its ability to preserve intravascular volume more effectively than crystalloids. However, gelatin may have detrimental effects on kidney function and increase the risk of acute kidney injury (AKI).

METHOD

We investigated by retrospective analysis of prospectively collected data whether the administration of 4% succinyl gelatin is associated with an increased risk of AKI after cardiac surgery. We compared two propensity score-matched groups of 1,187 patients (crystalloid group and gelatin group).

RESULTS

The incidence of AKI was similar in both groups (gelatin 21% and crystalloid 20%) (p = 0.414). The incidence of moderate AKI (8% vs. 6%) was higher in the gelatin group, but there was no difference in mild or severe AKI. Postoperative serum creatine on the first (70 vs. 70 μmol L^-1 , p = 0.689) or fourth (71 vs. 70, p = 0.313) postoperative day was similar between groups and there was no difference in the need for new renal replacement therapy (p = 0.999). Patients in the gelatin group received less crystalloids (2080 ml vs. 4130 ml, p = 0.001) and total fluids (3760 ml vs. 4180 ml, p = 0.001), their fluid balance was less positive (p = 0.001) and they required less vasoactive and inotropic medication (p = 0.001). Gelatin was not associated with increased mortality compared to the crystalloid group.

CONCLUSION

Gelatin was not associated with AKI after cardiac surgery.

Transfusion thresholds for guiding red blood cell transfusion

BACKGROUND

The optimal haemoglobin threshold for use of red blood cell (RBC) transfusions in anaemic patients remains an active field of research. Blood is a scarce resource, and in some countries, transfusions are less safe than in others because of inadequate testing for viral pathogens. If a liberal transfusion policy does not improve clinical outcomes, or if it is equivalent, then adopting a more restrictive approach could be recognised as the standard of care.  OBJECTIVES: The aim of this review update was to compare 30-day mortality and other clinical outcomes for participants randomised to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all clinical conditions. The restrictive transfusion threshold uses a lower haemoglobin concentration as a threshold for transfusion (most commonly, 7.0 g/dL to 8.0 g/dL), and the liberal transfusion threshold uses a higher haemoglobin concentration as a threshold for transfusion (most commonly, 9.0 g/dL to 10.0 g/dL).

SEARCH METHODS

We identified trials through updated searches: CENTRAL (2020, Issue 11), MEDLINE (1946 to November 2020), Embase (1974 to November 2020), Transfusion Evidence Library (1950 to November 2020), Web of Science Conference Proceedings Citation Index (1990 to November 2020), and trial registries (November 2020). We  checked the reference lists of other published reviews and relevant papers to identify additional trials. We were aware of one trial identified in earlier searching that was in the process of being published (in February 2021), and we were able to include it before this review was finalised.

SELECTION CRITERIA

We included randomised trials of surgical or medical participants that recruited adults or children, or both. We excluded studies that focused on neonates. Eligible trials assigned intervention groups on the basis of different transfusion schedules or thresholds or 'triggers'. These thresholds would be defined by a haemoglobin (Hb) or haematocrit (Hct) concentration below which an RBC transfusion would be administered; the haemoglobin concentration remains the most commonly applied marker of the need for RBC transfusion in clinical practice. We included trials in which investigators had allocated participants to higher thresholds or more liberal transfusion strategies compared to more restrictive ones, which might include no transfusion. As in previous versions of this review, we did not exclude unregistered trials published after 2010 (as per the policy of the Cochrane Injuries Group, 2015), however, we did conduct analyses to consider the differential impact of results of trials for which prospective registration could not be confirmed.   DATA COLLECTION AND ANALYSIS: We identified trials for inclusion and extracted data using Cochrane methods. We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two review authors independently extracted data and assessed risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as being in the 'restrictive transfusion' group and those randomly allocated to the higher transfusion threshold as being in the 'liberal transfusion' group.

MAIN RESULTS

A total of 48 trials, involving data from 21,433 participants (at baseline), across a range of clinical contexts (e.g. orthopaedic, cardiac, or vascular surgery; critical care; acute blood loss (including gastrointestinal bleeding); acute coronary syndrome; cancer; leukaemia; haematological malignancies), met the eligibility criteria. The haemoglobin concentration used to define the restrictive transfusion group in most trials (36) was between 7.0 g/dL and 8.0 g/dL.  Most trials included only adults; three trials focused on children. The included studies were generally at low risk of bias for key domains including allocation concealment and incomplete outcome data. Restrictive transfusion strategies reduced the risk of receiving at least one RBC transfusion by 41% across a broad range of clinical contexts (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.53 to 0.66; 42 studies, 20,057 participants; high-quality evidence), with a large amount of heterogeneity between trials (I² = 96%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.99, 95% CI 0.86 to 1.15; 31 studies, 16,729 participants; I² = 30%; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (all high-quality evidence)). High-quality evidence shows that the liberal transfusion threshold did not affect the risk of infection (pneumonia, wound infection, or bacteraemia). Transfusion-specific reactions are uncommon and were inconsistently reported within trials. We noted less certainty in the strength of evidence to support the safety of restrictive transfusion thresholds for the following predefined clinical subgroups: myocardial infarction, vascular surgery, haematological malignancies, and chronic bone-marrow disorders.

AUTHORS' CONCLUSIONS

Transfusion at a restrictive haemoglobin concentration decreased the proportion of people exposed to RBC transfusion by 41% across a broad range of clinical contexts. Across all trials, no evidence suggests that a restrictive transfusion strategy impacted 30-day mortality, mortality at other time points, or morbidity (i.e. cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. Despite including 17 more randomised trials (and 8846 participants), data remain insufficient to inform the safety of transfusion policies in important and selected clinical contexts, such as myocardial infarction, chronic cardiovascular disease, neurological injury or traumatic brain injury, stroke, thrombocytopenia, and cancer or haematological malignancies, including chronic bone marrow failure.  Further work is needed to improve our understanding of outcomes other than mortality. Most trials compared only two separate thresholds for haemoglobin concentration, which may not identify the actual optimal threshold for transfusion in a particular patient. Haemoglobin concentration may not be the most informative marker of the need for transfusion in individual patients with different degrees of physiological adaptation to anaemia. Notwithstanding these issues, overall findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds between the range of 7.0 g/dL and 8.0 g/dL. Some patient subgroups might benefit from RBCs to maintain higher haemoglobin concentrations; research efforts should focus on these clinical contexts.

Reoperation for bleeding in an elective cardiac surgical population - Does it affect survival?

Introduction: Earlier studies have shown that re-operation for bleeding after cardiac surgery is associated with increased mortality and morbidity in both acute and elective patients. The aim of the study was to assess the effect of re-operation for bleeding on short- and long-term survival and the causes of re-operation on an exclusively elective population.

Methods: This was a single-center, retrospective study conducted at the Department of Cardiothoracic Surgery at Copenhagen University Hospital. Rigshospitalet, Denmark. We included all elective patients undergoing first-time coronary bypass, valve surgery or combinations hereof between January 1998 and February 2014. Data was obtained from the electronic patient records on demographics, cardiological risk profile, blood transfusion and surgical record.

Results: A total of 11813 patients were included in the analysis of whom 626 (5.3%) patients underwent re-operation for bleeding. Patients were divided into two groups; non re-operated (NRO) and re-operated(RO). Baseline characteristics were comparable. Median survival was lover in the RO group (142 vs 160months (P = 0.001)). Morbidity and 30 day mortality was significantly higher in the RO group. Cox-regression analysis showed a significantly increased age-adjusted risk of death in the RO group (HR 1.21(1.07-1.37). P = 0.003). In 85% of the patients the site of bleeding was found during the re-operation.

Conclusion: We found both short and long-term survival to be lower in the RO group. A surgical cause for re-operation was found in the majority of cases. The study shows the importance of meticulous hemostasis during cardiac surgery.

Quality Management of a Comprehensive Blood Conservation Program During Cardiopulmonary Bypass

BACKGROUND

Red blood cell transfusion is common and associated with adverse outcomes for cardiac surgery, while present blood conservation guidelines have not been fully implemented until now. This study aims to evaluate our comprehensive blood conservation program after quality management, exploring its impact on blood transfusion and outcomes in patients undergoing cardiopulmonary bypass (CPB).

METHODS

We retrospectively compared blood transfusions and outcomes of patients from two different time periods, before and after the quality management of the comprehensive blood conservation program. The comprehensive program included restrictive transfusion protocols, conventional ultrafiltration, cell salvage, residual pump blood ultrafiltration and a modified mini-extracorporeal circulation system. A 1:1 propensity score matching and subgroup analysis were conducted.

RESULTS

3977 pairs were created, a significant decrease of red cell transfusion was observed during CPB (28.4% vs 18.6%, p＜.001), in the operation (40.7% vs 34.3%, p＜.001 ) and after the operation (6.2% vs 4.3%, p＜.001). 30-day mortality and some major complications also reduced. Subgroup analysis showed that the comprehensive blood conservation program was more beneficial for the following patients: above 60, male and the medium-risk European System for Cardiac Operative Risk Evaluation (EuroSCORE) of score 3-5.

CONCLUSIONS

The comprehensive blood conservation program during CPB is safe and effective in adult cardiac surgery, reducing blood utilization with no adverse outcomes. For the patients who are older, male and EuroSCORE 3-5, blood transfusion should be more cautious.

ABO Mismatch in Allogeneic Hematopoietic Stem Cell Transplant: Effect on Short- and Long-term Outcomes

Supplemental Digital Content is available in the text.

Background.

The impact of ABO incompatibility (ABO-I) on hematopoietic stem cell transplant outcomes is still debated.

Methods.

We retrospectively investigated 432 consecutive transplants performed at our center (2012–2020). All patients but 6 were affected by hematologic malignancies. The effect of different ABO match combinations on engraftment rate, transfusion support, acute and chronic graft-versus-host disease incidences, nonrelapse mortality (NRM), disease-free survival, and overall survival was assessed in univariate and multivariate analysis. Significance was set at P < 0.05.

Results.

ABO match distribution among transplants was as follows: 223 ABO-compatible, 94 major ABO-I, 82 minor ABO-I, and 33 bidirectional ABO-I. At univariate analysis, major ABO-I delayed the engraftment of neutrophils, platelets, and erythroid cells. At multivariate analysis, major ABO-I transplants displayed delayed erythroid engraftment (odds ratio [OR], 0.51; 95% confidence intervals [CIs], 0.38-0.70; P < 0.0001) and hindered transfusion independence for both red blood cells (OR, 0.52; 95% CI, 0.37-0.72; P = 0.0001) and platelets (0.60; 95% CI, 0.45-0.86; P = 0.0048). Moreover, major ABO-I transplants received greater amounts of blood products (P < 0.0001 for red blood cells and P = 0.0447 for platelets). In comparison with other ABO matches, major ABO-I was associated with an increased NRM (OR, 1.67; 95% CI, 1.01-2.75; P = 0.0427). No effects of ABO-mismatch were found on graft-versus-host disease, disease-free survival, and overall survival.

Conclusions.

Major ABO mismatch delays multilineage engraftment hinders transfusion independence and increases NRM. The prognostic impact of transfusion burden in hematopoietic stem cell transplantation deserves to be explored.

Effect of blood transfusions on cognitive development in very low birth weight infants

OBJECTIVE

Preterm infants frequently receive red cell transfusions; however, the effect of transfusions on cognition is unclear. We evaluated the relationship between transfusions and cognitive outcomes in preterm infants enrolled in a randomized trial of erythropoiesis stimulating agents (ESAs).

STUDY DESIGN

Preterm infants were randomized to ESAs or placebo during initial hospitalization, and transfusions recorded. Children were evaluated using standard developmental tests of cognition at 18-22 months (56 ESA, 24 placebo) and 3.5-4 years (39 ESA, 14 placebo).

RESULTS

Cognitive scores at 18-22 months were inversely correlated with transfusion volume (p = 0.02). Among those receiving ≥1 transfusion, cognitive scores were significantly higher in the ESA-treated group (p = 0.003). At 3.5-4 years, transfusions were not correlated with cognitive scores.

CONCLUSIONS

In the placebo group, transfused children had lower cognitive scores than did non-transfused children at 18-22 months. In the ESA group, cognitive scores did not differ by transfusion status, suggesting ESAs might provide neuroprotection.

Mini-sternotomy versus conventional sternotomy for aortic valve replacement: a randomised controlled trial

OBJECTIVE

To compare clinical and health economic outcomes after manubrium-limited mini-sternotomy (intervention) and conventional median sternotomy (usual care).

DESIGN

A single-blind, randomised controlled trial.

SETTING

Single centre UK National Health Service tertiary hospital.

PARTICIPANTS

Adult patients undergoing aortic valve replacement (AVR) surgery.

INTERVENTIONS

Intervention was manubrium-limited mini-sternotomy performed using a 5-7 cm midline incision. Usual care was median sternotomy performed using a midline incision from the sternal notch to the xiphisternum.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the proportion of patients who received a red cell transfusion postoperatively and within 7 days of index surgery. Secondary outcomes included proportion of patients receiving a non-red cell blood component transfusion and number of units transfused within 7 days and during index hospital stay, quality of life and cost-effectiveness analyses.

RESULTS

270 patients were randomised, received surgery and contributed to the intention to treat analysis. No difference between mini and conventional sternotomy in red-cell transfusion within 7 days was found; 23/135 patients in each arm received a transfusion, OR 1.0 (95% CI 0.5 to 2.0) and risk difference 0.0 (95% CI -0.1 to 0.1). Mini-sternotomy reduced chest drain losses (mean 181.6 mL (SD 138.7) vs conventional, mean 306·9 mL (SD 348.6)); this did not reduce red-cell transfusions. Mean valve size and postoperative valve function were comparable between mini-sternotomy and conventional groups; 23 mm vs 24 mm and 6/134 moderate or severe aortic regurgitation vs 3/130, respectively. Mini-sternotomy resulted in longer bypass (82.7 min (SD 23.5) vs 59.6 min (SD 15.1)) and cross-clamp times (64.1 min (SD 17.1) vs 46·3 min (SD 10.7)). Conventional sternotomy was more cost-effective with only a 5.8% probability of mini-sternotomy being cost-effective at a willingness to pay of £20 000/QALY (Quality Adjusted Life Years).

CONCLUSIONS

AVR via mini-sternotomy did not reduce red blood cell transfusion within 7 days following surgery when compared with conventional sternotomy.

TRIAL REGISTRATION NUMBER

ISRCTN29567910; Results.

Restrictive vs liberal red blood cell transfusion strategies in patients with acute myocardial infarction and anemia: Rationale and design of the REALITY trial

Background

Anemia is common in patients with acute myocardial infarction (AMI), and is an independent predictor of mortality. The optimal transfusion strategy in these patients is unclear.

Hypothesis

We hypothesized that a “restrictive” transfusion strategy (triggered by hemoglobin ≤8 g/dL) is clinically noninferior to a “liberal” transfusion strategy (triggered by hemoglobin ≤10 g/dL), but is less costly.

Methods

REALITY is an international, randomized, multicenter, open‐label trial comparing a restrictive vs a liberal transfusion strategy in patients with AMI and anemia. The primary outcome is the incremental cost‐effectiveness ratio (ICER) at 30 days, using the primary composite clinical outcome of major adverse cardiovascular events (MACE; comprising all‐cause death, nonfatal stroke, nonfatal recurrent myocardial infarction, or emergency revascularization prompted by ischemia) as the effectiveness criterion. Secondary outcomes include the ICER at 1 year, and MACE (and its components) at 30 days and at 1 year.

Results

The trial aimed to enroll 630 patients. Based on estimated event rates of 11% in the restrictive group and 15% in the liberal group, this number will provide 80% power to demonstrate clinical noninferiority of the restrictive group, with a noninferiority margin corresponding to a relative risk equal to 1.25. The sample size will also provide 80% power to show the cost‐effectiveness of the restrictive strategy at a threshold of €50 000 per quality‐adjusted life year.

Conclusions

REALITY will provide important guidance on the management of patients with AMI and anemia.

Perioperative Nadir Hemoglobin Concentration and Outcome in Off-Pump Coronary Artery Bypass Surgery - A Retrospective Review

BACKGROUND

Emerging evidence advocates the use of restrictive transfusion strategies at hemoglobin (Hb) levels of approximately 7-8 g/dL in cardiac surgeries using cardiopulmonary bypass. Yet, it is unclear whether the same thresholds can be applied to off-pump coronary bypass (OPCAB) that accompanies cardiac displacement and warm regional ischemia-reperfusion injury without the aid of a bypass machine. The aim of this study is to investigate the relationship between perioperative nadir Hb level and outcome following OPCAB.

METHODS AND RESULTS

Medical records of 1,360 patients were reviewed. Hb levels were serially assessed during and after surgery. The incidence of composite endpoints was 35%, which included myocardial infarction, stroke, acute kidney injury, sternal infection, reoperation, prolonged mechanical ventilation, and in-hospital mortality. The nadir Hb level was significantly lower in the morbidity group than in the non-morbidity group (8.1 [7.4-9.1] vs. 8.8 [7.9-9.8] g/dL, P<0.001). Multivariable logistic regression analysis revealed nadir Hb as an independent risk factor of adverse outcome (odds ratio: 0.878, 95% confidence intervals: 0.776-0.994, P=0.04), whereas preoperative anemia and perioperative transfusion were not. The critical value of Hb for predicting detrimental outcome was 8.05 g/dL.

CONCLUSIONS

A significant association is found between perioperative nadir Hb and adverse outcome after OPCAB. Although preoperative anemia was not associated with poor prognosisper se, it was the only modifiable risk factor that was closely linked to nadir Hb.

Gelatin and the risk of bleeding after cardiac surgery

BACKGROUND

Gelatins has been used in cardiac surgery because of their ability to preserve intravascular volume better than crystalloids. Unfortunately, gelatin has been associated with impaired coagulation and hemostasis, that may cause increased bleeding. We investigated whether the administration of gelatin increases postoperative bleeding after cardiac surgery.

METHODS

Retrospective, observational single-center cohort study in the intensive care unit of a tertiary teaching hospital. Postoperative bleeding, chest tube drainage volume and consumption of blood products were compared between groups.

RESULTS

Cohort included 3067 consecutive patients who underwent cardiac surgery. First 1698 patients received gelatin (gelatin group), and 1369 patients did not (crystalloid group). The characteristics of the patients in the gelatin and crystalloid groups were comparable. Postoperative chest tube drainage was 18% (95% CI 11%-20%) greater during the first 12 hours (P < .001) and 15% (95% CI 7%-17%) greater during the first 24 hours (P < .001) in the gelatin group compared to the crystalloid group. Severe and massive postoperative bleeding was more common in the gelatin group compared to the crystalloid group (21% vs 16%, P < .001). Patients in the gelatin group received red blood cells (40% vs 20%, P < .001) and platelets (12% vs 8%, P < .001) more frequently than patients in the crystalloid group. However, the number of administered fresh-frozen plasma transfusions did not differ between the groups.

CONCLUSION

Gelatin may increase postoperative bleeding and the need for blood product transfusions after cardiac surgery.

Viscoelastic testing in cardiac surgery

Bleeding complications are common in cardiac surgery and lead to an increase in morbidity and mortality. This is multifactorial in aetiology including the effects of cardiopulmonary bypass, the drugs given to manipulate the coagulation system and the vascular nature of the surgery itself. Viscoelastic tests provide a point of care, rapid assessment of coagulation which offer the advantage of faster turnaround times and a nuanced view of the elements of the coagulation system allowing targeted therapy to be delivered quickly. Both thomboelastography (TEG)and thromboelastometry (ROTEM) have been recommended for use in cardiac surgery, both have shown a reduction in transfusion and bleeding when used as part of a testing algorithm. They are particularly useful in assessing residual heparinisation and fibrinogen levels. Additionally, TEG allows the evaluation of the effects of anti-platelet agents on platelet function. This review discusses the mechanisms by which bleeding occurs in cardiac surgery and explores three uses of viscoelastic testing in cardiac surgery: to predict bleeding, to assess platelet function and peri-operative testing to reduce transfusion.

Systematic reviews and meta-analyses comparing mortality in restrictive and liberal haemoglobin thresholds for red cell transfusion: an overview of systematic reviews

BACKGROUND

There are no overviews of systematic reviews investigating haemoglobin thresholds for transfusion. This is important as the literature on transfusion thresholds has grown considerably in recent years. Our aim was to synthesise evidence from systematic reviews and meta-analyses of the effects of restrictive and liberal transfusion strategies on mortality.

METHODS

This was a systematic review of systematic reviews (overview). We searched MEDLINE, Embase, Web of Science Core Collection, PubMed, Google Scholar, and the Joanna Briggs Institute EBP Database, from 2008 to 2018. We included systematic reviews and meta-analyses of randomised controlled trials comparing mortality in patients assigned to red cell transfusion strategies based on haemoglobin thresholds. Two independent reviewers extracted data and assessed methodological quality. We assessed the methodological quality of included reviews using AMSTAR 2 and the quality of evidence pooled using an algorithm to assign GRADE levels.

RESULTS

We included 19 systematic reviews reporting 33 meta-analyses of mortality outcomes from 53 unique randomised controlled trials. Of the 33 meta-analyses, one was graded as high quality, 15 were moderate, and 17 were low. Of the meta-analyses presenting high- to moderate-quality evidence, 12 (75.0%) reported no statistically significant difference in mortality between restrictive and liberal transfusion groups and four (25.0%) reported significantly lower mortality for patients assigned to a restrictive transfusion strategy. We found few systematic reviews addressed clinical differences between included studies: variation was observed in haemoglobin threshold concentrations, the absolute between group difference in haemoglobin threshold concentration, time to randomisation (resulting in transfusions administered prior to randomisation), and transfusion dosing regimens.

CONCLUSIONS

Meta-analyses graded as high to moderate quality indicate that in most patient populations no difference in mortality exists between patients assigned to a restrictive or liberal transfusion strategy.

TRIAL REGISTRATION

PROSPERO CRD42019120503.

Evolution of perioperative blood transfusion practice after coronary artery bypass grafting in the past two decades

BACKGROUND AND AIM OF THE STUDY

Transfusion of blood products after coronary artery bypass grafting (CABG) is associated with increased morbidity and mortality. We evaluated the perioperative use of blood products in patients undergoing CABG in our institution over the past two decades.

METHODS

The study included 18 992 patients who underwent isolated CABG at our hospital between 1998 and 2017. Baseline characteristics of patients and the number of perioperative transfusions during their hospital stay (including red blood cells [RBCs], platelets, and fresh frozen plasma [FFP]) were assessed. Logistic regression models were used to identify risk factors for perioperative transfusion.

RESULTS

The rates of perioperative RBC transfusion decreased for all patients undergoing isolated CABG (52.1% in 1998 vs 18.6% in 2017) in our institution. The mean number of transfused RBC units was significantly higher in women than in men (1.57 ± 2.2 vs 0.68 ± 1.84; P < .005); this difference remained significant over the years. After adjusting the results for other risk factors, female sex was a significant independent risk factor for perioperative RBC transfusion. The platelet transfusion rate increased over the past two decades (1.4% in 1998 vs 9.7% in 2017). The number of FFP transfusions remained unchanged.

CONCLUSIONS

Over the past two decades, we observed a decrease in the incidence of perioperative RBC transfusions in patients undergoing isolated CABG, whereas platelet transfusions increased. Female sex was an independent predictor of perioperative RBC transfusion.

Red cell transfusion practices after stage 1 palliation: a survey of practitioners from the Pediatric Cardiac Intensive Care Society

INTRODUCTION

Neonates may require increased red cell mass to optimise oxygen content after stage 1 palliation; however, data informing transfusion practices are limited. We hypothesise there is a patient-, provider-, and institution-based heterogeneity in red cell transfusion decision-making after stage 1 palliation.

METHODS

We conducted an online survey of Pediatric Cardiac Intensive Care Society practitioners in 2016. Respondents answered scenario-based questions that defined transfusion indications and identified haematocrit transfusion thresholds. Respondents were divided into restrictive and liberal groups based on a haematocrit score. Fisher's exact test was used to determine the associations between transfusion likelihood and patient, provider, and institutional characteristics. Bonferroni correction was applied to adjust the p-value to 0.004 for multiple comparisons.

RESULTS

There was a 21% response rate (116 responses). Most were male (58.6%), attending physicians (85.3%) with >5 year of intensive care experience (88.7%) and subspeciality training in critical care medicine (47.4%). The majority of institutions were academic (96.6%), with a separate cardiac ICU (86.2%), and performed >10 stage 1 palliation cases annually (68.1%). After Bonferroni correction, there were no significant patient, respondent, or institutional differences between the restrictive and liberal groups. No respondent or institutional characteristics influenced transfusion decision-making after stage 1 palliation.

CONCLUSIONS

Decision-making around red cell transfusion after stage 1 palliation is heterogeneous. We found no clear relationships between patient, respondent, or institutional characteristics and transfusion decision-making among surveyed respondents. Given the lack of existing data informing red cell transfusion after stage 1 palliation, further studies are necessary to inform evidence-based guidelines.

Systematic reviews and meta-analyses comparing mortality in restrictive and liberal haemoglobin thresholds for red cell transfusion: protocol for an overview of systematic reviews

INTRODUCTION

There has been a significant increase in the number of systematic reviews and meta-analyses of randomised controlled trials investigating thresholds for red blood cell transfusion. To systematically collate, appraise and synthesise the results of these systematic reviews and meta-analyses, we will conduct an overview of systematic reviews.

METHODS AND ANALYSIS

This is a protocol for an overview of systematic reviews. We will search five databases: MEDLINE, Embase, Web of Science Core Collection, PubMed (for prepublication, in process and non-Medline records) and Google Scholar. We will consider systematic reviews and meta-analyses of randomised controlled trials evaluating the effect of haemoglobin thresholds for red blood cell transfusion on mortality. Two authors will independently screen titles and abstracts retrieved in the literature search and select studies meeting the eligibility criteria for full-text review. We will extract data onto a predefined form designed to summarise the key characteristics of each review. We will assess the methodological quality of included reviews and the quality of evidence in included reviews.

ETHICS AND DISSEMINATION

Formal ethics approval is not required for this overview as we will only analyse published literature. The findings of this study will be presented at relevant conferences and submitted for peer-review publication. The results are likely to be used by clinicians, policy makers and developers of clinical guidelines and will inform suggestions for future systematic reviews and randomised controlled trials.

PROSPERO REGISTRATION NUMBER

CRD42019120503.

Can Preoperative C-Reactive Protein Predict Bleeding After On-Pump Coronary Artery Bypass Grafting?

BACKGROUND

Bleeding after cardiac surgery remains a challenge. Numerous studies suggest that higher level of C-reactive protein (CRP) increases cardiovascular risk. There is limited information revealing the association of preoperative CRP concentration and postoperative bleeding while undergoing on-pump coronary artery bypass grafting (CABG). This study aimed to investigate the relationship between preoperative CRP level and postoperative bleeding within 24 hours after CABG.

METHODS

Data on 1055 patients accepting isolated primary CABG at Fuwai Hospital, Chinese Academy of Medical Sciences from September 2017 to July 2018 were recorded. Preoperative CRP concentration, laboratory coagulation parameters, intraoperative data, and postoperative bleeding volume within 24 hours after surgery were recorded. The primary endpoint was bleeding volume within 24 hours after surgery. We analyzed the correlation between bleeding volume within 24 hours after surgery and preoperative data with univariate and multiple linear regression.

RESULTS

Preoperative CRP concentration (B = -0.094, P < .001), platelet count (B = -0.115, P < .01), thrombocytocrit (B = -0.127, P < .001), prothrombin time (B = 0.052, P < .01), and fibrinogen (B = -0.096, P < .01) were univariably correlated with postoperative bleeding volume. However preoperative CRP concentration (B = -0.089, P < .05) was an independent predictor of postoperative bleeding volume after multiple linear regression. Preoperative CRP concentration was also associated with body mass index (B = 0.068, P = .038), activated partial thromboplastin time (B = 0.089, P < .01), and fibrinogen (B = 0.519, P < .01) after multiple linear regression.

CONCLUSIONS

Our findings suggested that preoperative CRP concentration independently correlated with postoperative bleeding volume within 24 hours and that it could be a new potential coagulation biomarker for patients undergoing CABG surgery.

Perioperative mortality secondary to a pulmonary embolism during a surgical implantation of the Endo-Exo-Prosthesis: a case report

We report on a 53‐year‐old female patient who suffered a perioperative death secondary to a pulmonary embolism (PE) during an implantation of Endo‐Exo‐Prosthesis. This is a retrospective review of medical case for a patient who had a previous above‐the‐knee amputation secondary to a failed previous arthroplasty surgery. Our planned surgery was a stage 1 implantation of an Endo‐Exo‐Prosthesis, and it was performed under general anaesthesia. After 25 min from starting the surgical procedure, the patient sustained a cardiac arrest, and despite an active cardiopulmonary resuscitation for 50 min, the patient did not recover, the ventilator machine was stopped later on, and the patient was declared deceased at that stage. Fatal intraoperative PE is a rare but significant complication during orthopaedic procedures. There are few reports of similar events but include mainly trauma patients with fractured neck of femur. Endo‐Exo‐Prosthesis is a relatively newly evolved procedure in a unique group of patients. To our knowledge, this is the first case report of such complication during Endo‐Exo‐Prosthesis implantation. Patient and surgeon should be aware of it, and additional preventive measures like preoperative scoring systems and in special cases using inferior vena cava filter should be considered in patients with high risk of developing venous thromboembolism.

Should Transfusion Trigger Thresholds Differ for Critical Care Versus Perioperative Patients? A Meta-Analysis of Randomized Trials

Supplemental Digital Content is available in the text.

Objective:

To address the significant uncertainty as to whether transfusion thresholds for critical care versus surgical patients should differ.

Design:

Meta-analysis of randomized controlled trials.

Setting:

Medline, EMBASE, and Cochrane Library searches were performed up to 15 June 2016.

Patients:

Trials had to enroll adult surgical or critically ill patients for inclusion.

Interventions:

Studies had to compare a liberal versus restrictive threshold for the transfusion of allogeneic packed RBCs.

Measurements and Main Results:

The primary outcome was 30-day all-cause mortality, sub-grouped by surgical and critical care patients. Secondary outcomes included myocardial infarction, stroke, renal failure, allogeneic blood exposure, and length of stay. Odds ratios and weighted mean differences were calculated using random effects meta-analysis. To assess whether subgroups were significantly different, tests for subgroup interaction were used. Subgroup analysis by trials enrolling critically ill versus surgical patients was performed. Twenty-seven randomized controlled trials (10,797 patients) were included. In critical care patients, restrictive transfusion resulted in significantly reduced 30-day mortality compared with liberal transfusion (odds ratio, 0.82; 95% CI, 0.70–0.97). In surgical patients, a restrictive transfusion strategy led to the opposite direction of effect for mortality (odds ratio, 1.31; 95% CI, 0.94–1.82). The subgroup interaction test was significant (p = 0.04), suggesting that the effect of restrictive transfusion on mortality is statistically different for critical care (decreased risk) versus surgical patients (potentially increased risk or no difference). Regarding secondary outcomes, for critically ill patients, a restrictive strategy resulted in reduced risk of stroke/transient ischemic attack, packed RBC exposure, transfusion reactions, and hospital length of stay. In surgical patients, restrictive transfusion resulted in reduced packed RBC exposure.

Conclusions:

The safety of restrictive transfusion strategies likely differs for critically ill patients versus perioperative patients. Further trials investigating transfusion strategies in the perioperative setting are necessary.

Does Transfusion of Blood and Blood Products Increase the Length of Stay in Hospital?

We aimed to analyze the use of blood products in cardiac surgery and to investigate its effect on clinical outcomes. Perioperative transfusion requirement, survival and complication rates and the duration of hospitalization were noted. Patients were divided into two groups considering the duration of hospital and intensive care unit (ICU) stay. The cardiopulmonary bypass time and the cross clamp time, and the amount of used cryoprecipitate, fresh frozen plasma, platelet, red blood cell and the bleeding amount were significantly higher in groups that stayed at the hospital for > 7 days and at the ICU for > 2 days (p > 0.05). In the univariate model, to predict the patients who might stay at the hospital for more than 1 week and who might stay at the ICU for more than 3 days, we considered the significant efficacy of postoperative blood transfusion, bleeding amount, and the cardiopulmonary bypass time (p < 0.05). In the reduced multivariate model, however, we analyzed the significant-independent efficacy of the postoperative fresh frozen plasma use to determine the patients who would stay at the hospital for more than 1 week and who would stay at the ICU for more than 3 days (p < 0.05). We have concluded that increased use of blood products was associated with the cross clamp and cardiopulmonary bypass time and prolonged duration of hospital and ICU stays. In open cardiac surgeries, the use of blood products due to bleeding was identified as a predictor for staying longer than 3 days at the ICU and longer than 7 days at the hospital.

Noteworthy Literature Published in 2018 for Cardiothoracic Anesthesiologists

The year 2018 was marked by high-quality, impactful articles spanning the basic, translational, and clinical spectrum in the field of cardiothoracic anesthesia. In this article, we present several hand-picked articles from the past year that we feel were the most significant in shaping our specialty. Large multicenter, randomized controlled trials presenting clinical outcome data dominated the publishing arena: is a restrictive red blood cell transfusion strategy superior to a liberal red blood cell transfusion strategy during cardiopulmonary bypass? Does a low mean arterial blood pressure strategy during cardiopulmonary bypass increase stroke incidence? Does the obesity paradox apply to cardiac surgery? Advancing technology continues to revolutionize our field: can the MitraClip be used to effectively treat secondary mitral regurgitation? Can stem cells improve cardiac function in patients with left ventricular assist devices? These studies allow us to shape our practice in an evidence-based manner, so that we may evolve as a specialty and deliver the best care to our patients.

Restrictive compared with liberal red cell transfusion strategies in cardiac surgery: a meta-analysis

AIMS

To determine whether a restrictive strategy of red blood cell (RBC) transfusion at lower haemoglobin concentrations is inferior to a liberal strategy of RBC transfusion at higher haemoglobin concentrations in patients undergoing cardiac surgery.

METHODS AND RESULTS

We conducted a systematic review, meta-analysis, and trial sequential analysis of randomized controlled trials of the effect of restrictive and liberal RBC transfusion strategies on mortality within 30 days of surgery as the primary outcome. Secondary outcomes were those potentially resulting from anaemia-induced tissue hypoxia and transfusion outcomes. We searched the electronic databases MEDLINE, EMBASE, and the Cochrane Library until 17 November 2017. Thirteen trials were included. The risk ratio (RR) of mortality derived from 4545 patients assigned to a restrictive strategy when compared with 4547 transfused according to a liberal strategy was 0.96 [95% confidence interval (CI) 0.76-1.21, I2 = 0]. A restrictive strategy did not have a statistically significant effect on the risk of myocardial infarction (RR 1.01, 95% CI 0.81-1.26; I2=0), stroke (RR 0.93, 95% CI 0.68-1.27, I2 = 0), renal failure (RR 0.96, 95% CI 0.76-1.20, I2 = 0), or infection (RR 1.12, 95% CI 0.98-1.29, I2 = 0). Subgroup analysis of adult and paediatric trials did not show a significant interaction. At approximately 70% of the critical information size, the meta-analysis of mortality crossed the futility boundary for inferiority of the restrictive strategy.

CONCLUSION

The current evidence does not support the notion that restrictive RBC transfusion strategies are inferior to liberal RBC strategies in patients undergoing cardiac surgery.