Liberal or restrictive transfusion after cardiac surgery

Relationship between the magnitude of haemoglobin changes and long-term mortality in patients with sepsis: a retrospective cohort study

BACKGROUND

Sepsis is a common and severe disease with a high mortality rate in intensive care unit (ICU). The hemoglobin (HGB) level is a key parameter for oxygen supply in sepsis. Although HGB is associated with the progression of inflammation in sepsis patients, its role as a marker following sepsis treatment remains unclear. Here, we studied the correlation between early temporal changes in HGB levels and long-term mortality rates in septic patients.

METHOD

In this retrospective study of data on patients with sepsis from the Medical Information Mart for Intensive Care (MIMIC) IV database, the outcome was long-term mortality. Patients were divided based on the cut-off of the HGB percentage for receiver operating characteristic (ROC) curve calculation. Kaplan-Meier (KM) survival curves and Cox proportional hazards regression models were used to analyse the associations between groups and outcomes. Propensity score matching (PSM) was used to verify the results.

RESULTS

In this study, 2042 patients with sepsis and changes in HGB levels at day 4 after admission compared to day 1 were enrolled and divided into two groups: group 1 (n = 1147) for those with reduction of HGB < 7% and group 2 (n = 895) for those with dropping ≥ 7%. The long-term survival chances of sepsis with less than a 7% reduction in the proportion of HGB at day four were significantly higher than those of patients in the group with a reduction of 7% or more. After adjusting for covariates in the Cox model, the hazard ratios (HRs) with 95% confidence intervals (CIs) for long-term all-cause mortality in the group with a reduction of 7% or more were as follows: 180 days [HR = 1.41, 95% CI (1.22 to 1.63), P < 0.001]; 360 days [HR = 1.37, 95% CI (1.21 to 1.56), P < 0.001]; 540 days [HR = 1.35, 95% CI (1.20 to 1.53), P < 0.001]; 720 days [HR = 1.45, 95% CI (1.29 to 1.64), P < 0.001]. Additionally, the long-term survival rates, using Kaplan-Meier analysis, for the group with a reduction of 7% or more were lower compared to the group with less than 7% reduction at 180 days (54.3% vs. 65.3%, P < 0.001), 360 days (42.3% vs. 50.9%, P < 0.001), 540 days (40.2% vs. 48.6%, P < 0.001), and 720 days (35.5% vs. 46.1%, P < 0.001). The same trend was obtained after using PSM.

CONCLUSION

A ≥ 7% decrease in HGB levels on Day 4 after admission was associated with worse long-term prognosis in sepsis patients admitted to the ICU.

Conventional versus minimally invasive extra-corporeal circulation in patients undergoing cardiac surgery: A randomized controlled trial (COMICS)

INTRODUCTION

The trial hypothesized that minimally invasive extra-corporeal circulation (MiECC) reduces the risk of serious adverse events (SAEs) after cardiac surgery operations requiring extra-corporeal circulation without circulatory arrest.

METHODS

This is a multicentre, international randomized controlled trial across fourteen cardiac surgery centres including patients aged ≥18 and <85 years undergoing elective or urgent isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR) surgery, or CABG + AVR surgery. Participants were randomized to MiECC or conventional extra-corporeal circulation (CECC), stratified by centre and operation. The primary outcome was a composite of 12 post-operative SAEs up to 30 days after surgery, the risk of which MiECC was hypothesized to reduce. Secondary outcomes comprised: other SAEs; all-cause mortality; transfusion of blood products; time to discharge from intensive care and hospital; health-related quality-of-life. Analyses were performed on a modified intention-to-treat basis.

RESULTS

The trial terminated early due to the COVID-19 pandemic; 1071 participants (896 isolated CABG, 97 isolated AVR, 69 CABG + AVR) with median age 66 years and median EuroSCORE II 1.24 were randomized (535 to MiECC, 536 to CECC). Twenty-six participants withdrew after randomization, 22 before and four after intervention. Fifty of 517 (9.7%) randomized to MiECC and 69/522 (13.2%) randomized to CECC group experienced the primary outcome (risk ratio = 0.732, 95% confidence interval (95% CI) = 0.556 to 0.962, p = 0.025). The risk of any SAE not contributing to the primary outcome was similarly reduced (risk ratio = 0.791, 95% CI 0.530 to 1.179, p = 0.250).

CONCLUSIONS

MiECC reduces the relative risk of primary outcome events by about 25%. The risk of other SAEs was similarly reduced. Because the trial terminated early without achieving the target sample size, these potential benefits of MiECC are uncertain.

Post-operative infections after cardiothoracic surgery and vascular procedures: a bibliometric and visual analysis of the 100 most-cited articles in the past 2 decades

Aim

To recognize and analyze the 100 most-cited articles on post-operative infections following cardiothoracic surgery and vascular procedures in the past 20 years.

Methods

Articles published on post-operative infections following cardiothoracic surgery and vascular procedures from inception 1986 till 2020 were reviewed and selected by two authors, based on their number of citations using the Scopus database. Their characteristics were recorded, i.e., title, authors, publication date, total no. of citations, citations per year (CPY), country of research, institutional affiliation, journal, research subject, and article type.

Results

The top 100 most influential articles were published between 1968 and 2017, with the peak in 2002. The mean number of total citations was 236.79 (range: 108-1,157). Areas with a medical focus were predominant in the studied research articles on the researched topic. The top-most journals in which these articles were published include Annals of Thoracic Surgery (14), followed by Circulation (8), and the New England Journal of Medicine (8). The number of publications affiliated with an institution were highest in the United States, with the Cleveland Clinic Foundation (6) having the most.

Conclusion

These findings highlight that there is a great potential to conduct research and publish the prevalence, causes, risk factors, pathogenesis and molecular biology of post-cardiac and -vascular surgery infections to prevent their adverse effects. The results can be taken into consideration for policy making to improve post-cardiac-surgery outcomes.

Data-driven coaching to improve statewide outcomes in CABG: before and after interventional study

BACKGROUND

The impact of quality improvement initiatives program (QIP) on coronary artery bypass grafting surgery (CABG) remains scarce, despite improved outcomes in other surgical areas. This study aims to evaluate the impact of a package of QIP on mortality rates among patients undergoing CABG.

MATERIALS AND METHODS

This prospective cohort study utilized data from the multicenter database Registro Paulista de Cirurgia Cardiovascular II (REPLICCAR II), spanning from July 2017 to June 2019. Data from 4018 isolated CABG adult patients were collected and analyzed in three phases: before-implementation, implementation, and after-implementation of the intervention (which comprised QIP training for the hospital team). Propensity Score Matching was used to balance the groups of 2170 patients each for a comparative analysis of the following outcomes: reoperation, deep sternal wound infection/mediastinitis ≤30 days, cerebrovascular accident, acute kidney injury, ventilation time >24 h, length of stay <6 days, length of stay >14 days, morbidity and mortality, and operative mortality. A multiple regression model was constructed to predict mortality outcomes.

RESULTS

Following implementation, there was a significant reduction of operative mortality (61.7%, P =0.046), as well as deep sternal wound infection/mediastinitis ( P <0.001), sepsis ( P =0.002), ventilation time in hours ( P <0.001), prolonged ventilation time ( P =0.009), postoperative peak blood glucose ( P <0.001), total length of hospital stay ( P <0.001). Additionally, there was a greater use of arterial grafts, including internal thoracic ( P <0.001) and radial ( P =0.038), along with a higher rate of skeletonized dissection of the internal thoracic artery.

CONCLUSIONS

QIP was associated with a 61.7% reduction in operative mortality following CABG. Although not all complications exhibited a decline, the reduction in mortality suggests a possible decrease in failure to rescue during the after-implementation period.

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.

Noninvasive hemoglobin monitoring for maintaining hemoglobin concentration within the target range during major noncardiac surgery: A randomized controlled trial

STUDY OBJECTIVE

The effect of noninvasive CO-oximetry hemoglobin (SpHb) monitoring on the clinical outcomes of patients undergoing surgery remains unclear. This trial aimed to evaluate whether SpHb monitoring helps maintain hemoglobin levels within a predefined target range during major noncardiac surgeries with a potential risk of intraoperative hemorrhage.

DESIGN

A single-center, prospective, randomized controlled trial.

SETTING

University hospital.

PATIENTS

One hundred and thirty patients undergoing elective noncardiac surgery with a potential risk of hemorrhage.

INTERVENTIONS

Patients were randomly allocated to undergo either SpHb-guided management (SpHb group) or usual care (control group).

MEASUREMENTS

The primary outcome was the rate of deviation of the total hemoglobin concentration (determined from laboratory testing) from a pre-specified target range (8-14 g/dL). This was defined as the number of laboratory tests revealing such deviations divided by the total number of laboratory tests performed during the surgery.

MAIN RESULTS

The primary outcome occurred significantly less frequently in the SpHb group as compared to that in the control group (15/555 [2.7%]) vs. 68/598 [11.4%]; relative risk, 0.24; 95% confidence interval, 0.13-0.41; P < 0.001). Fewer point-of-care blood tests were performed in the SpHb group than in the control group (median [interquartile range], 2 [1-4] vs. 4 [2-5]; P < 0.001). There were no significant intergroup differences in the number of patients who received red blood cell transfusions during surgery (SpHb vs. control, 33.8% vs. 46.2%; P = 0.201). The incidence of unnecessary red blood cell preparation (>2 units) was lower in the SpHb group than in the control group (3.1% vs. 16.9%; P = 0.024).

CONCLUSIONS

Compared with routine care, SpHb-guided management resulted in significantly lower rates of hemoglobin deviation outside the target range intraoperatively in patients undergoing major noncardiac surgeries with a potential risk of hemorrhage.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03816514).

Inhaled NO at a crossroads in cardiac surgery: current need to improve mechanistic understanding, clinical trial design and scientific evidence

Inhaled nitric oxide (NO) has been used in pediatric and adult perioperative cardiac intensive care for over three decades. NO is a cellular signaling molecule that induces smooth muscle relaxation in the mammalian vasculature. Inhaled NO has the unique ability to exert its vasodilatory effects in the pulmonary vasculature without any hypotensive side-effects in the systemic circulation. In patients undergoing cardiac surgery, NO has been reported in numerous studies to exert beneficial effects on acutely lowering pulmonary artery pressure and reversing right ventricular dysfunction and/or failure. Yet, various investigations failed to demonstrate significant differences in long-term clinical outcomes. The authors, serving as an advisory board of international experts in the field of inhaled NO within pediatric and adult cardiac surgery, will discuss how the existing scientific evidence can be further improved. We will summarize the basic mechanisms underlying the clinical applications of inhaled NO and how this translates into the mandate for inhaled NO in cardiac surgery. We will move on to the popular use of inhaled NO and will talk about the evidence base of the use of this selective pulmonary vasodilator. This review will elucidate what kind of clinical and biological barriers and gaps in knowledge need to be solved and how this has impacted in the development of clinical trials. The authors will elaborate on how the optimization of inhaled NO therapy, the development of biomarkers to identify the target population and the definition of response can improve the design of future large clinical trials. We will explain why it is mandatory to gain an international consensus for the state of the art of NO therapy far beyond this expert advisory board by including the different major players in the field, such as the different medical societies and the pharma industry to improve our understanding of the real-life effects of inhaled NO in large scale observational studies. The design for future innovative randomized controlled trials on inhaled NO therapy in cardiac surgery, adequately powered and based on enhanced biological phenotyping, will be crucial to eventually provide scientific evidence of its clinical efficacy beyond its beneficial hemodynamic properties.

Blood transfusion reactions and risk of acute kidney injury and major adverse kidney events

BACKGROUND

Blood transfusion reactions may have a negative impact on organ function. It is unknown whether this association holds true for acute kidney injury (AKI). Therefore, we conducted a cohort study to assess the association between transfusion reactions and the incidence of AKI and major adverse kidney events.

METHODS

In this retrospective cohort study, we included patients who received transfusion of blood products during hospitalization at the Hospital Civil of Guadalajara. We analyzed them according to the development of transfusion reactions, and the aim was to assess the association between transfusion reactions and AKI during long-term follow-up.

RESULTS

From 2017 to 2021, 81,635 patients received a blood product transfusion, and 516 were included in our study. The most common transfusion was red blood cell packaging (50.4%), fresh frozen plasma (28.7%) and platelets (20.9%); of the 516 patients, 129 (25%) had transfusion reactions. Patients who had transfusion reactions were older and had more comorbidities. The most common type of transfusion reaction was allergic reaction (70.5%), followed by febrile nonhemolytic reaction (11.6%) and anaphylactoid reaction (8.5%). Most cases were considered mild. Acute kidney injury was more prevalent among those who had transfusion reactions (14.7%) than among those who did not (7.8%), p =  < 0.01; those with AKI had a higher frequency of diabetes, vasopressors, and insulin use. Transfusion reactions were independently associated with the development of AKI (RR 2.1, p =  < 0.02). Major adverse kidney events were more common in those with transfusion reactions. The mortality rate was similar between subgroups.

CONCLUSION

In our retrospective cohort of patients who received blood product transfusions, 25% experienced transfusion reactions, and this event was associated with a twofold increase in the probability of developing AKI and some of the major adverse kidney events during long follow-up.

Outcomes of minimally invasive versus conventional sternotomy for redo mitral valve surgery according to Mitral Valve Academic Research Consortium: A systematic review and meta-analysis

A minimally invasive approach through right mini-thoracotomy for redo mitral valve surgery may improve patients' outcomes compared to median sternotomy. This study aims to evaluate the outcomes of both procedures according to the Mitral Valve Academic Research Consortium (MVARC). This systematic review and meta-analysis were performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Literature searching was performed in several databases including PubMed, EBSCOhost, Scopus, and Proquest up to 28 February 2022. Meta-analysis using proportions or means was applied. A total of 13 retrospective cohort articles were included in this study. The incidence of in-hospital mortality (3% vs 9.2%, OR = 0.35; 95% CI: 0.21-0.58; P ≤ 0.0001), reintervention for bleeding (3.8% vs 5.9%, OR = 0.56; 95% CI: 0.32-0.97; P = 0.04), and acute renal failure (5% vs 12%, OR = 0.29; 95% CI: 0.23-0.65; P = 0.0003) was significantly lower in mini-thoracotomy (MINI) group compared to median sternotomy (STER) group. The incidence of neurologic events (3.4% vs 5.5%, OR = 0.66; 95% CI: 0.4-1.08; P = 0.1) and arrhythmia (19.5% vs 25.5%, OR = 0.64; 95% CI: 0.38-1.09; P = 0.1) were also lower in MINI group compared to STER group but was not significant statistically. No significant differences were found in myocardial infarct (1% vs 1%, OR = 0.71; 95% CI: 0.06-8.85; P = 0.79) between MINI and STER group. A minimally invasive surgery through right mini-thoracotomy is associated with a lower incidence of in-hospital mortality, reintervention for bleeding, and acute renal failure. It is a safe alternative to median sternotomy for redo mitral valve surgery.

Red Blood Cell Transfusion Requirements Before and After Implementation of a Perioperative Patient Blood Management Program in Adult Patients Undergoing Cardiac Surgery. A Before and After Observational Study

OBJECTIVES

Anemia and transfusion are common in cardiac surgery patients, and are associated with significant morbidity and mortality. Multiple perioperative interventions have been described to reduce blood transfusion, but are rarely combined altogether. The aim of this study was to compare the incidence of red blood cell (RBC) transfusion in adult patients undergoing cardiac surgery before and after the implementation of a perioperative patient blood management (PBM) program.

DESIGN

Before-and-after observational study.

SETTING

Single-center French university teaching hospital.

PARTICIPANTS

Adult patients scheduled for cardiac surgery.

INTERVENTIONS

Perioperative patient blood management program including pre-, intra-, and postoperative interventions aimed at identifying and correcting anemia, minimizing blood loss during surgery, and optimizing coagulation.

MEASUREMENTS AND MAIN RESULTS

Four hundred thirty-four patients were included in the study from January 2021 to July 2022. The incidence of perioperative RBC transfusion (intraoperatively and during the first 2 postoperative days) was significantly reduced from 43% (90/213) in the pre-PBM period to 27% (60/221) in the post-PBM period (p < 0.001). The application of a PBM program was associated with a reduction in perioperative RBC transfusion by multivariate analysis (odds ratio 0.55, 95% CI 0.36-0.85, p = 0.007), and was associated with a reduction in the median number of RBC units transfused within transfused patients (p = 0.025). These effects persisted at day 30 after surgery (p = 0.029).

CONCLUSION

A perioperative PBM program in adult patients undergoing cardiac surgery was associated with a significant reduction in perioperative RBC transfusion, which persisted at day 30.

Restrictive or Liberal Transfusion Strategy in Myocardial Infarction and Anemia

BACKGROUND

A strategy of administering a transfusion only when the hemoglobin level falls below 7 or 8 g per deciliter has been widely adopted. However, patients with acute myocardial infarction may benefit from a higher hemoglobin level.

METHODS

In this phase 3, interventional trial, we randomly assigned patients with myocardial infarction and a hemoglobin level of less than 10 g per deciliter to a restrictive transfusion strategy (hemoglobin cutoff for transfusion, 7 or 8 g per deciliter) or a liberal transfusion strategy (hemoglobin cutoff, <10 g per deciliter). The primary outcome was a composite of myocardial infarction or death at 30 days.

RESULTS

A total of 3504 patients were included in the primary analysis. The mean (±SD) number of red-cell units that were transfused was 0.7±1.6 in the restrictive-strategy group and 2.5±2.3 in the liberal-strategy group. The mean hemoglobin level was 1.3 to 1.6 g per deciliter lower in the restrictive-strategy group than in the liberal-strategy group on days 1 to 3 after randomization. A primary-outcome event occurred in 295 of 1749 patients (16.9%) in the restrictive-strategy group and in 255 of 1755 patients (14.5%) in the liberal-strategy group (risk ratio modeled with multiple imputation for incomplete follow-up, 1.15; 95% confidence interval [CI], 0.99 to 1.34; P = 0.07). Death occurred in 9.9% of the patients with the restrictive strategy and in 8.3% of the patients with the liberal strategy (risk ratio, 1.19; 95% CI, 0.96 to 1.47); myocardial infarction occurred in 8.5% and 7.2% of the patients, respectively (risk ratio, 1.19; 95% CI, 0.94 to 1.49).

CONCLUSIONS

In patients with acute myocardial infarction and anemia, a liberal transfusion strategy did not significantly reduce the risk of recurrent myocardial infarction or death at 30 days. However, potential harms of a restrictive transfusion strategy cannot be excluded. (Funded by the National Heart, Lung, and Blood Institute and others; MINT ClinicalTrials.gov number, NCT02981407.).

Hemoglobin levels and clinical outcomes after extracorporeal circulation auxiliary to open heart surgery: a retrospective cohort study

BACKGROUND

Extracorporeal circulation auxiliary to open heart surgery is a common procedure used to treat heart diseases. However, the optimal transfusion strategy for patients undergoing this surgery remains a subject of debate. This study aims to investigate the association between hemoglobin levels and clinical outcomes in patients undergoing extracorporeal circulation auxiliary to open heart surgery, with the ultimate goal of improving surgical success rates and enhancing patients' quality of life.

METHODS

A retrospective analysis was conducted on data from the Medical Information Mart for Intensive Care IV 2.2 (MIMIC-IV 2.2) database, including 4144 patients. The patients were categorized into five groups based on their minimum hemoglobin levels during hospitalization. Baseline characteristics, clinical scores, laboratory results, and clinical outcome data were collected. Statistical analyses utilized descriptive statistics, ANOVA or Kruskal-Wallis tests, Kaplan-Meier method, and Log-rank test.

RESULTS

The results revealed a significant correlation between hemoglobin levels and in-hospital mortality, as well as mortality rates at 30 days, 60 days, and 180 days (p < 0.001). Patients with lower hemoglobin levels exhibited higher mortality rates. However, once hemoglobin levels exceeded 7g/dL, no significant difference in mortality rates was observed (p = 0.557). Additionally, lower hemoglobin levels were associated with prolonged hospital stay, ICU admission time, and mechanical ventilation time (p < 0.001). Furthermore, hemoglobin levels were significantly correlated with complication risk, norepinephrine dosage, and red blood cell transfusion volume (p < 0.001). However, there was no significant difference among the groups in terms of major complications, specifically sepsis (p > 0.05).

CONCLUSION

The study highlights the importance of managing hemoglobin levels in patients undergoing heart surgery with extracorporeal circulation. Hemoglobin levels can serve as valuable indicators for predicting clinical outcomes and guiding treatment decisions. Physicians should carefully consider hemoglobin levels to optimize transfusion strategies and improve postoperative patient outcomes. Further research and intervention studies are warranted to validate and implement these findings in clinical practice.

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.

Survey of the Impact of Decision Support in Preoperative Management of Anemia (i-Anemia): Survey Study

BACKGROUND

Major surgery on patients with anemia has demonstrated an increased risk of perioperative blood transfusions and postoperative morbidity and mortality. Recent studies have shown that integrating preoperative anemia treatment as a component of perioperative blood management may reduce blood product utilization and improve outcomes in both cardiac and noncardiac surgery. However, outpatient management of anemia falls outside of daily practice for most anesthesiologists and is probably weakly understood.

OBJECTIVE

We conducted a simulated case survey with anesthesiologists to accomplish the following aims: (1) evaluate the baseline knowledge of the preoperative optimization of anemia and (2) determine the impact of real-time clinical decision support on anemia management.

METHODS

We sent a digital survey (i-Anemia) to members of the French Society of Anaesthesia and Critical Care. The i-Anemia survey contained 7 simulated case vignettes, each describing a patient's brief clinical history and containing up to 3 multiple-choice questions related to preoperative anemia management (12 questions in total). The cases concerned potential situations of preoperative anemia and were created and validated with a committee of patient blood management experts. Correct answers were determined by the current guidelines or by expert consensus. Eligible participants were randomly assigned to control or decision support groups. In the decision support group, the primary outcome measured was the correct response rate.

RESULTS

Overall, 1123 participants were enrolled and randomly divided into control (n=568) and decision support (n=555) groups. Among them, 763 participants fully responded to the survey. We obtained a complete response rate of 65.6% (n=364) in the group receiving cognitive aid and 70.2% (n=399) in the group without assistance. The mean duration of response was 10.2 (SD 6.8) minutes versus 7.8 (SD 5) minutes for the decision support and control groups, respectively (P<.001). The score significantly improved with cognitive aid (mean 10.3 out of 12, SD 2.1) in comparison to standard care (mean 6.2 out of 12, SD 2.1; P<.001).

CONCLUSIONS

Management strategies to optimize preoperative anemia are not fully known and applied by anesthesiologists in daily practice despite their clinical importance. However, adding a decision support tool can significantly improve patient care by reminding practitioners of current recommendations.

Intravenous iron administration before cardiac surgery reduces red blood cell transfusion in patients without anaemia

BACKGROUND

Reducing the need for blood transfusion among patients undergoing cardiac surgery FLA reduce postoperative complications and mortality. Our study aimed to assess the effects of administering preoperative i.v. ferric carboxymaltose on postoperative red cell transfusion requirements in patients without anaemia undergoing on-pump cardiac surgery.

METHODS

This double-blind, randomised, placebo-controlled trial was conducted between October 2016 and November 2019, with a follow-up period of up to 6 weeks after surgery. Patients without anaemia who underwent on-pump cardiac surgery were included as participants and administered i.v. iron in the form of ferric carboxymaltose or placebo once, 24-72 h before surgery. The primary outcome was the number of red cell units transfused during the first four postoperative days, and the secondary outcome measures were blood haemoglobin concentrations at 4 days and 6 weeks after surgery.

RESULTS

The 200 patients included were randomly assigned to the ferric carboxymaltose (n=102) and placebo (n=98) groups. By postoperative Day 4, a significantly lower mean number of red cell units were transfused in the ferric carboxymaltose than in the placebo group, 0.3 (0.8) vs 1.6 (4.4), respectively; P=0.007. The mean haemoglobin concentrations on postoperative Day 4 were 9.7 (1) g dl-1 and 9.3 (1) g dl-1, respectively (P=0.03). Corresponding values at 6 weeks after surgery were 12.6 (1.4) g dl-1 and 11.8 (1.5) g dl-1, respectively (P=0.012).

CONCLUSIONS

In patients without anaemia undergoing on-pump cardiac surgery, treatment with a single dose of 1000 mg ferric carboxymaltose i.v. 1-3 days before surgery significantly reduced the need for red cell transfusions and increased the postoperative haemoglobin concentration.

CLINICAL TRIAL REGISTRATION

NCT02939794.

Red Blood Cell Transfusion in the Intensive Care Unit

Importance

Red blood cell (RBC) transfusion is common among patients admitted to the intensive care unit (ICU). Despite multiple randomized clinical trials of hemoglobin (Hb) thresholds for transfusion, little is known about how these thresholds are incorporated into current practice.

Objective

To evaluate and describe ICU RBC transfusion practices worldwide.

Design, Setting, and Participants

International, prospective, cohort study that involved 3643 adult patients from 233 ICUs in 30 countries on 6 continents from March 2019 to October 2022 with data collection in prespecified weeks.

Exposure

ICU stay.

Main Outcomes and Measures

The primary outcome was the occurrence of RBC transfusion during ICU stay. Additional outcomes included the indication(s) for RBC transfusion (consisting of clinical reasons and physiological triggers), the stated Hb threshold and actual measured Hb values before and after an RBC transfusion, and the number of units transfused.

Results

Among 3908 potentially eligible patients, 3643 were included across 233 ICUs (median of 11 patients per ICU [IQR, 5-20]) in 30 countries on 6 continents. Among the participants, the mean (SD) age was 61 (16) years, 62% were male (2267/3643), and the median Sequential Organ Failure Assessment score was 3.2 (IQR, 1.5-6.0). A total of 894 patients (25%) received 1 or more RBC transfusions during their ICU stay, with a median total of 2 units per patient (IQR, 1-4). The proportion of patients who received a transfusion ranged from 0% to 100% across centers, from 0% to 80% across countries, and from 19% to 45% across continents. Among the patients who received a transfusion, a total of 1727 RBC transfusions were administered, wherein the most common clinical indications were low Hb value (n = 1412 [81.8%]; mean [SD] lowest Hb before transfusion, 7.4 [1.2] g/dL), active bleeding (n = 479; 27.7%), and hemodynamic instability (n = 406 [23.5%]). Among the events with a stated physiological trigger, the most frequently stated triggers were hypotension (n = 728 [42.2%]), tachycardia (n = 474 [27.4%]), and increased lactate levels (n = 308 [17.8%]). The median lowest Hb level on days with an RBC transfusion ranged from 5.2 g/dL to 13.1 g/dL across centers, from 5.3 g/dL to 9.1 g/dL across countries, and from 7.2 g/dL to 8.7 g/dL across continents. Approximately 84% of ICUs administered transfusions to patients at a median Hb level greater than 7 g/dL.

Conclusions and Relevance

RBC transfusion was common in patients admitted to ICUs worldwide between 2019 and 2022, with high variability across centers in transfusion practices.

Red Blood Cell Transfusion: 2023 AABB International Guidelines

Importance

Red blood cell transfusion is a common medical intervention with benefits and harms.

Objective

To provide recommendations for use of red blood cell transfusion in adults and children.

Evidence Review

Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed.

Findings

For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence).

Conclusions and Relevance

It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.

An analysis of quality of life and functional outcomes as reported in randomized trials for red cell transfusions

BACKGROUND

Meta-analyses of randomized controlled trials (RCTs) evaluating thresholds for red blood cell (RBC) transfusion typically focus on mortality; however, other outcomes are highly relevant. The aim of this study is to summarize the effects of different transfusion thresholds on the outcomes of quality of life (QoL) and function.

STUDY DESIGN

We extracted data from RCTs identified in a recently published Cochrane systematic review. Primary analysis was descriptive.

RESULTS

A total of 23 RCTs with 13,743 adult participants were included. Fifteen RCTs included patients in the postoperative period, of which 9 RCTs were conducted in hip (n = 3024) and 6 (n = 8672) in cardiac surgeries; 5 RCTs (n = 489) were in patients with hematological malignancies; 2 in the setting of bleeding (gastrointestinal bleed [n = 936] and postpartum [n = 521]); and one RCT (n = 936) included critically ill patients. QoL and function were reported using a variety of questionnaires and tools. The timing of assessments varied between trials. No clear clinical differences in QoL outcomes were identified in comparisons between restrictive and liberal transfusion thresholds.

DISCUSSION

There is no evidence that a liberal transfusion strategy improves QoL and functional outcomes. However, the substantial limitations of many included studies indicate the need for further well-designed and adequately powered trials.

Data-Driven Blood Transfusion Thresholds for Severely Injured Patients During Blood Shortages

INTRODUCTION

Crises like the COVID-19 pandemic create blood product shortages. Patients requiring transfusions are placed at risk and institutions may need to judiciously administer blood during massive blood transfusions protocols (MTP). The purpose of this study is to provide data-driven guidance for the modification of MTP when the blood supply is severely limited.

METHODS

This is a retrospective cohort study of 47 Level I and II trauma centers (TC) within a single healthcare system whose patients received MTP from 2017 to 2019. All TC used a unifying MTP protocol for balanced blood product transfusions. The primary outcome was mortality as a function of volume of blood transfused and age. Hemoglobin thresholds and measures of futility were also estimated. Risk-adjusted analyses were performed using multivariable and hierarchical regression to account for confounders and hospital variation.

RESULTS

Proposed MTP maximum volume thresholds for three age groupings are as follows: 60 units for ages 16-30 y, 48 units for ages 31-55 y, and 24 units for >55 y. The range of mortality under the transfusion threshold was 30%-36% but doubled to 67-77% when the threshold was exceeded. Hemoglobin concentration differences relative to survival were clinically nonsignificant. Prehospital measures of futility were prehospital cardiac arrest and nonreactive pupils. In hospital risk factors of futility were mid-line shift on brain CT and cardiopulmonary arrest.

CONCLUSIONS

Establishing MTP threshold practices under blood shortage conditions, such as the COVID pandemic, could sustain blood availability by following relative thresholds for MTP use according to age groups and key risk factors.

Red Blood Cell Transfusion Guided by Hemoglobin Only or Integrating Perfusion Markers in Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis With Trial Sequential Analysis

OBJECTIVE

Strategies for red blood cell (RBC) transfusion in patients undergoing cardiac surgery have been traditionally anchored to hemoglobin (Hb) targets. A more physiologic approach would consider markers of organ hypoperfusion.

DESIGN

The authors conducted a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials (RCTs).

SETTING

Cardiac surgery.

PARTICIPANTS

Adult patients.

INTERVENTION

RBC transfusion targeting only Hb levels compared with strategies combining Hb values with markers of organ hypoperfusion.

MEASUREMENTS AND MAIN RESULTS

Primary outcomes were the number of RBC units transfused, the number of patients transfused at least once, and the average number of transfusions. Secondary outcomes were postoperative complications, intensive care (ICU) and hospital lengths of stay, and mortality. Only 2 RCTs were included (n = 257 patients), and both used central venous oxygen saturation (ScvO2) as a marker of organ hypoperfusion (cut-off: <70% or ≤65%). A transfusion protocol combining Hb and ScvO2 reduced the overall number of RBC units transfused (risk ratio [RR]: 1.57 [1.33-1.85]; p < 0.0001, I2 = 0%), and the number of patients transfused at least once (RR: 1.33 [1.16-1.53]; p < 0.0001, I2 = 41%), but not the average number of transfusions (mean difference [MD]: 0.18 [-0.11 to 0.47]; p = 0.24, I2 = 66%), with moderate certainty of evidence. Mortality (RR: 1.29, [0.29-5.77]; p = 0.73, I2 = 0%), ICU length-of-stay (MD: -0.06 [-0.58 to 0.46]; p = 0.81, I2 = 0%), hospital length-of-stay (MD: -0.05 [-1.49 to 1.39];p = 0.95, I2 = 0%), and all postoperative complications were not affected.

CONCLUSIONS

In adult patients undergoing cardiac surgery, a restrictive protocol integrating Hb values with a marker of organ hypoperfusion (ScvO2) reduces the number of RBC units transfused and the number of patients transfused at least once without apparent signals of harm. These findings were preliminary and warrant further multicentric research.

Cardiac surgery-Associated acute kidney injury - A narrative review

Cardiac Surgery-Associated Acute Kidney Injury (CSA-AKI) is a serious complication seen in approximately 20-30% of cardiac surgery patients. The underlying pathophysiology is complex, often involving both patient- and procedure related risk factors. In contrast to AKI occurring after other types of major surgery, the use of cardiopulmonary bypass comprises both additional advantages and challenges, including non-pulsatile flow, targeted blood flow and pressure as well as the ability to manipulate central venous pressure (congestion). With an increasing focus on the impact of CSA-AKI on both short and long-term mortality, early identification and management of high-risk patients for CSA-AKI has evolved. The present narrative review gives an up-to-date summary on definition, diagnosis, underlying pathophysiology, monitoring and implications of CSA-AKI, including potential preventive interventions. The review will provide the reader with an in-depth understanding of how to identify, support and provide a more personalized and tailored perioperative management to avoid development of CSA-AKI.

The intensity of organ support: Restrictive or aggressive therapy for critically ill patients

The intensity of organ support has received attention in recent years. To make better clinical decisions, we should understand the mechanisms and benefits, and disadvantages of the different intensities of organ support in critically ill patients. Therapeutic strategies such as supplemental oxygen therapy, mechanical ventilation, respiratory stimulant, vasoactive agents, transfusion, albumin infusion, fluid management, renal placement, and nutrition support, if they are implemented in accordance with an aggressive strategy, could result in side effects and/or complications, resulting in iatrogenic harm in critically ill patients. It is found that the intensity of organ support is not a determining factor in prognosis. A normal rather than supernormal physiological target is recommended for support therapy.

Effects of interventions targeting the systemic inflammatory response to cardiac surgery on clinical outcomes in adults

BACKGROUND

Organ injury is a common and severe complication of cardiac surgery that contributes to the majority of deaths. There are no effective treatment or prevention strategies. It has been suggested that innate immune system activation may have a causal role in organ injury. A wide range of organ protection interventions targeting the innate immune response have been evaluated in randomised controlled trials (RCTs) in adult cardiac surgery patients, with inconsistent results in terms of effectiveness.

OBJECTIVES

The aim of the review was to summarise the results of RCTs of organ protection interventions targeting the innate immune response in adult cardiac surgery. The review considered whether the interventions had a treatment effect on inflammation, important clinical outcomes, or both.

SEARCH METHODS

CENTRAL, MEDLINE, Embase, conference proceedings and two trial registers were searched on October 2022 together with reference checking to identify additional studies.

SELECTION CRITERIA

RCTs comparing organ protection interventions targeting the innate immune response versus placebo or no treatment in adult patients undergoing cardiac surgery where the treatment effect on innate immune activation and on clinical outcomes of interest were reported.

DATA COLLECTION AND ANALYSIS

Searches, study selection, quality assessment, and data extractions were performed independently by pairs of authors. The primary inflammation outcomes were peak IL-6 and IL-8 concentrations in blood post-surgery. The primary clinical outcome was in-hospital or 30-day mortality. Treatment effects were expressed as risk ratios (RR) and standardised mean difference (SMD) with 95% confidence intervals (CI). Meta-analyses were performed using random effects models, and heterogeneity was assessed using I2.

MAIN RESULTS

A total of 40,255 participants from 328 RCTs were included in the synthesis. The effects of treatments on IL-6 (SMD -0.77, 95% CI -0.97 to -0.58, I2 = 92%) and IL-8 (SMD -0.92, 95% CI -1.20 to -0.65, I2 = 91%) were unclear due to heterogeneity. Heterogeneity for inflammation outcomes persisted across multiple sensitivity and moderator analyses. The pooled treatment effect for in-hospital or 30-day mortality was RR 0.78, 95% CI 0.68 to 0.91, I2 = 0%, suggesting a significant clinical benefit. There was little or no treatment effect on mortality when analyses were restricted to studies at low risk of bias. Post hoc analyses failed to demonstrate consistent treatment effects on inflammation and clinical outcomes. Levels of certainty for pooled treatment effects on the primary outcomes were very low.

AUTHORS' CONCLUSIONS

A systematic review of RCTs of organ protection interventions targeting innate immune system activation did not resolve uncertainty as to the effectiveness of these treatments, or the role of innate immunity in organ injury following cardiac surgery.

A model based on electronic health records to predict transfusion events in on-pump cardiac surgery

Perioperative blood transfusion is costly and raises safety concerns. We developed and validated a model for predicting minor, moderate, or major transfusion given to patients during on-pump cardiac procedures based on two centers' database. Model performance incorporating 7 variables on the development set had an AUC of 0.803 [95% CI, 0.790-0.815] for minor transfusion; moderate transfusion, giving an AUC of 0.822 (95% CI, 0.803-0.841); and major transfusion, giving an AUC of 0.813 (95% CI, 0.759-0.866). Model performance on the validation set had an AUC of 0.739 (95% CI 0.714-0.765), 0.730 (95% CI 0.702-0.758), and 0.713 (95% CI 0.677-0.749), respectively. A model based entirely on readily available electronic health records can accurately predict intraoperative minor, moderate, or major transfusion and provide individualized transfusion risk profiles before surgery among those on-pump cardiac surgical patients, and may help guide patient management.

Valve Surgery in a Low-Volume Center in a Low- and Middle-Income Country: A Retrospective Cross-Sectional Study

Background

Valvular heart disease (VHD) has a significant prevalence and mortality rate with surgical intervention continuing to be a cornerstone of therapy. We aim to report the outcome of patients undergoing heart valve surgery (HVS) in a low-volume center (LVC) in a low- and middle-income country (LMIC).

Methods

A cross-sectional retrospective study was conducted at the Jordan University Hospital (JUH), a tertiary teaching hospital in a developing country, between April 2014 and December 2019. Patients who underwent mitral valve replacement (MVR), aortic valve replacement (AVR), tricuspid valve replacement (TVR), double valve replacement (DVR), CABG + MVR, and CABG + AVR patients were included. Thirty-day and two-year mortalities were taken as the primary and secondary outcomes, respectively.

Results

A total number of 122 patients were included, and the mean age was 54.46 ± 14.89 years. AVR was most common (42.6%). There was no significant association between STS mortality score or Euroscore II with 30-day and 2-year mortality.

Conclusion

LVC will continue to have a role in LMICs, especially during development to HICs. Further global studies are needed to assert the safety of HVS in LVC and LMICs.

Transfusion-associated adverse events incidence and severity after the implementation of an active hemovigilance program with 24 h follow-up. A prospective cohort study

BACKGROUND

Hemovigilance (HV) is usually based on voluntary reports (passive HV). Our aim is to ascertain credible incidence, severity, and mortality of transfusion-associated adverse events (TAAEs) using an active HV program.

STUDY DESIGN AND METHODS

Prospective cohort study to estimate transfusion risk after 46,488 transfusions in 5830 patients, using an active HV program with follow-up within the first 24 h after transfusion. We compared these results to those with the previously established passive HV program during the same 30 months of the study. We explored factors associated with the occurrence of TAAEs using generalized estimating equations models.

RESULTS

With the active HV program TAAEs incidence was 57.3 (95% CI, 50.5-64.2) and mortality 1.1 (95% CI, 0.13-2.01) per 10,000 transfusions. Incidence with the new surveillance model was 14.0 times higher than with the passive. Most events occurred when transfusions had already finished (60.2%); especially pulmonary events (80.4%). Three out of five deaths and 50.3% of severe TAAEs were pulmonary. In the multivariate analysis surgical patients had half TAAEs risk when compared to medical patients (OR, 0.53; 95% CI, 0.34-0.78) and women had nearly twice the risk of a pulmonary event compared to men (OR, 1.84; 95% CI, 1.03-3.32). Patient's age, blood component type, or blood component shelf-life were unrelated to TAAEs risk.

DISCUSSION

Active hemovigilance programs provide additional data which may lead to better recognition and understanding of TAAEs and their frequency and severity.

Red Blood Cell Conservation and Use in the Cardiovascular Operating Rooms at Ben Taub General Hospital

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.

How I treat anemia with red blood cell transfusion and iron

Severe anemia is commonly treated with red blood cell transfusion. Clinical trials have demonstrated that a restrictive transfusion strategy of 7 to 8 g/dL is as safe as a liberal transfusion strategy of 9 to 10 g/dL in many clinical settings. Evidence is lacking for subgroups of patients, including those with preexisting coronary artery disease, acute myocardial infarction, congestive heart failure, and myelodysplastic neoplasms. We present 3 clinical vignettes that highlight the clinical challenges in caring for patients with coronary artery disease with gastrointestinal bleeding, congestive heart failure, or myelodysplastic neoplasms. We emphasize that transfusion practice should be guided by patient symptoms and preferences in conjunction with the patient's hemoglobin concentration. Along with the transfusion decision, evaluation and management of the etiology of the anemia is essential. Iron-restricted erythropoiesis is a common cause of anemia severe enough to be considered for red blood cell transfusion but diagnosis and management of absolute iron deficiency anemia, the anemia of inflammation with functional iron deficiency, or their combination may be problematic. Intravenous iron therapy is generally the treatment of choice for absolute iron deficiency in patients with complex medical disorders, with or without coexisting functional iron deficiency.

Reduced Invasiveness of Cardiopulmonary Bypass: The Mini-Circuit and the Micro-Cardioplegia

The aim of cardiopulmonary bypass is the maintenance of a sufficient whole body perfusion and gas exchange during open or closed heart surgery procedure (coronary artery bypass grafting, valve repair and replacement, surgical intervention on the ascending aorta and/or aortic arch, repair of congenital malformations, and finally implantation of ventricular assist devices or cardiac transplantation). The main components of cardiopulmonary bypass are the pump that supplies the circulation and the oxygenator that regulates gas exchange. However, even though this technology has been extensively developed and improved over the last decades, one of the major drawbacks-which is the fact that blood has to flow through tubing systems with foreign surfaces-persists so far. Nevertheless, interesting innovations have been made more recently in order to better control the side-effects that culminate into a major activation of the coagulation and inflammatory systems: among them, miniaturization of the circuits, together with reduction of the priming volume and a simplified cardioplegia concept. All of these lead to a significant decrease of hemodilution and thereby a significant reduction of volume overload during surgery. In this brief review we will present some of these most interesting topics around minimized circuits and the simplified low-volume cardioplegia and discuss their potential benefits on the clinical outcome.

Impact of Red Blood Cell Transfusion on In-hospital Mortality of Isolated Coronary Artery Bypass Graft Surgery: A Retrospective Observational Study of French Nationwide 3-year Cohort

OBJECTIVE

To assess the relationship between red blood cell (RBC) transfusion exposure and in-hospital mortality after isolated coronary artery bypass graft (CABG) surgery.

BACKGROUND

RBC transfusion was commonly used to treat anemia in isolated CABG surgery, but transfusion was found an independent risk factor of postoperative mortality; recent guidelines on patient blood management strategy issued in the last decade may have changed transfusion incidence and related mortality.

METHODS

A retrospective cohort study was conducted from the National database on patients' hospital discharge reports. Consecutive adult patients who underwent isolated CABG surgery in France from January 1, 2016, to December 31, 2018, were included. The primary outcome was the in-hospital mortality rate. RBC transfusion during the hospital stay was identified by specific codes and ordered as categorical variables (no, moderate, or massive transfusion).

RESULTS

A total of 37,498 participants were studied [mean (SD) age, 66.5 (9.6) years, 31,587 (84.2%) were men]. In-hospital mortality rate was 1.45% (n=541) and RBC transfusion rate was 9.4% (n=3521). In-hospital deaths were more frequent among transfused patients [1.06% (361) if no transfusion up to 10.2% (n=113) if massive transfusion]. After adjustment for confounding variables, RBC transfusion remained a significant independent factor of in-hospital mortality: odds ratio=1.66 (95% confidence interval: 1.27-2.19, P <0.001) for moderate transfusion, 6.40 (95% confidence interval: 5.07-8.09, P <0.001) if massive.

CONCLUSIONS AND RELEVANCE

Despite a modest patients' exposure to transfusion, this study suggests that RBC administration is an independent factor of in-hospital mortality in isolated CABG surgery.

Postoperative Weight Gain within Enhanced Recovery after Cardiac Surgery

Optimal fluid therapy during perioperative care as part of enhanced recovery after cardiac surgery (ERACS) should improve the outcome. Our objective was finding out the effects of fluid overload on outcome and mortality within a well-established ERACS program. All consecutive patients undergoing cardiac surgery between January 2020 and December 2021 were enrolled. According to ROC curve analysis, a cut-off of ≥7 kg (group M, n = 1198) and <7 kg (group L, n = 1015) was defined. A moderate correlation was shown between weight gain and fluid balance r = 0.4, and a simple linear regression was significant p < 0.0001, R² = 0.16. Propensity score matching showed that increased weight gain was associated with a longer hospital length of stay (LOS) (L 8 [3] d vs. M 9 [6] d, p < 0.0001), an increased number of patients who received pRBCs (L 311 (36%) vs. M 429 (50%), p < 0.0001), and a higher incidence of postoperative acute kidney injury (AKI) (L 84 (9.8%) vs. M 165 (19.2%), p < 0.0001). Weight gain can easily represent fluid overload. Fluid overload after cardiac surgery is common and is associated with prolonged hospital LOS and increases the incidence of AKI.

A novel model for predicting a composite outcome of major complications after valve surgery

Background

On-pump valve surgeries are associated with high morbidity and mortality. The present study aimed to reliably predict a composite outcome of postoperative complications using a minimum of easily accessible clinical parameters.

Methods

A total of 7,441 patients who underwent valve surgery were retrospectively analyzed. Data for 6,220 patients at West China Hospital of Sichuan University were used to develop a predictive model, which was validated using data from 1,221 patients at the Second Affiliated Hospital of Zhejiang University School of Medicine. The primary outcome was a composite of major complications: all-cause death in hospital, stroke, myocardial infarction, and severe acute kidney injury. The predictive model was constructed using the least absolute shrinkage and selection operator as well as multivariable logistic regression. The model was assessed in terms of the areas under receiver operating characteristic curves, calibration, and decision curve analysis.

Results

The primary outcome occurred in 129 patients (2.1%) in the development cohort and 71 (5.8%) in the validation cohort. Six variables were retained in the predictive model: New York Heart Association class, diabetes, glucose, blood urea nitrogen, operation time, and red blood cell transfusion during surgery. The C-statistics were 0.735 (95% CI, 0.686-0.784) in the development cohort and 0.761 (95% CI, 0.694-0.828) in the validation cohort. For both cohorts, calibration plots showed good agreement between predicted and actual observations, and ecision curve analysis showed clinical usefulness. In contrast, the well-established SinoSCORE did not accurately predict the primary outcome in either cohort.

Conclusions

This predictive nomogram based on six easily accessible variables may serve as an "early warning" system to identify patients at high risk of major complications after valve surgery.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT04476134].

Cost Analysis of Aprotinin Reintroduction in French Cardiac Surgery Centres: A Real-World Data-Based Analysis

INTRODUCTION

The European Medicines Agency restored aprotinin (APR) use for preventing blood loss in patients undergoing isolated coronary artery bypass graft (iCABG) in 2016 but requested the collection of patient and surgery data in a registry (NAPaR). The aim of this analysis was to evaluate the impact of APR reintroduction in France on the main hospital costs (operating room, transfusion and intensive unit stay) compared to the current use of tranexamic acid (TXA), which was the only antifibrinolytic available before APR reinstatement.

METHODS

A multicenter before-after post-hoc analysis to compare APR and TXA was carried out in four French university hospitals. APR use followed the ARCOTHOVA (French Association of Cardiothoracic and Vascular Anesthetists) protocol, which had framed three main indications in 2018. Data from 236 APR patients were retrieved from the NAPaR (N = 874); 223 TXA patients were retrospectively retrieved from each center database and matched to APR patients upon indication classes. Budget impact was evaluated using both direct costs associated with antifibrinolytics and transfusion products (within the first 48 h) and other costs such as surgery duration and ICU stay.

RESULTS

The 459 collected patients were distributed as: 17% on-label; 83% off-label. Mean cost per patient until ICU discharge tended to be lower in the APR group versus the TXA group, which resulted in an estimated gross saving of €3136 per patient. These savings concerned operating room and transfusion costs but were mainly driven by reduced ICU stays. When extrapolated to the whole French NAPaR population, the total savings of the therapeutic switch was estimated at around €3 million.

CONCLUSION

The budget impact projected that using APR according to ARCOTHOVA protocol resulted in decreased requirement for transfusion and complications related to surgery. Both were associated with substantial cost savings from the hospital's perspective compared with exclusive use of TXA.

Incidence and Impact of a Single-Unit Red Blood Cell Transfusion: Analysis of The Society of Thoracic Surgeons Database 2010-2019

BACKGROUND

As the adverse effects of blood transfusions are better understood, recommendations support single-unit red blood cell (RBC) transfusions (SRBCT). However, an isolated SRBCT across the entire index admission suggests even the single unit may be avoidable. We sought to identify the characteristics of cardiac surgery patients receiving an isolated SRBCT and analyze the impact on outcomes.

METHODS

The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried for the period between January 1, 2010, and December 31, 2019. Patients aged >18 years undergoing isolated coronary artery bypass grafting or isolated aortic valve replacement were included. A total of 2,151,430 encounters were analyzed.

RESULTS

Of the 847,442 patients (39.3%) receiving any RBC transfusion during their index admission, 206,555 (24.4%) received only 1 unit. Propensity-matching analysis determined SRBCT patients were significantly older (67.26 vs 64.02 years; odds ratio [OR], 1.02; P < .001), female (39.1% vs 17.8%; OR, 1.57; P < .001), non-White (18.2% vs 13.1%; OR, 0.81; P < .001), and had a smaller body surface area (1.94 vs 2.07 m2; OR, 0.20; P < .001). They also had higher mortality (1.4% vs 1.0%, P < .001), stroke (1.7% vs 1.2%, P < .001), prolonged ventilation (6.4% vs 3.4%, P < .001), renal failure (1.8% vs 0.9%, P < .001), and reoperations (1.3% vs. 0.5%, P < .001) than patients who received 0 RBCs.

CONCLUSIONS

SRBCT is a common occurrence in adult cardiac surgery. This low-volume transfusion is strongly associated with higher morbidity, even after controlling for preoperative risk factors.

Transfusion trigger after operations in high cardiac risk patients (TOP) trial protocol. Protocol for a multicenter randomized controlled transfusion strategy trial

BACKGROUND

There is substantial uncertainty regarding the effects of restrictive postoperative transfusion among patients who have underlying cardiovascular disease. The TOP Trial's objective is to compare adverse outcomes between liberal and restrictive transfusion strategies in patients undergoing vascular and general surgery operations, and with a high risk of postoperative cardiac events.

METHODS

A two-arm, single-blinded, randomized controlled superiority trial will be used across 15 Veterans Affairs hospitals with expected enrollment of 1520 participants. Postoperative transfusions in the liberal arm commence when Hb is <10 g/ dL and continue until Hb is greater than or equal to 10 g/dL. In the restrictive arm, transfusions begin when Hb is <7 g/dL and continue until Hb is greater than or equal to 7 g/dL. Study duration is estimated to be 5 years including a 3-month start-up period and 4 years of recruitment. Each randomized participant will be followed for 90 days after randomization with a mortality assessment at 1 year.

RESULTS

The primary outcome is a composite endpoint of all-cause mortality, myocardial infarction (MI), coronary revascularization, acute renal failure, or stroke occurring up to 90-days after randomization. Events rates will be compared between restrictive and liberal transfusion groups.

CONCLUSIONS

The TOP Trial is uniquely positioned to provide high quality evidence comparing transfusion strategies among patients with high cardiac risk. Results will clarify the effect of postoperative transfusion strategies on adverse outcomes and inform postoperative management algorithms.

TRIAL REGISTRATION

http://clinicaltrials.gov identifier: NCT03229941.

Perioperative Anemia and Transfusions and Late Mortality in Coronary Artery Bypass Patients

BACKGROUND

Perioperative anemia and transfusions are associated with adverse operative outcomes after coronary artery bypass graft surgery (CABG). Their individual association with long-term outcomes is unclear.

METHODS

Patients aged 65 years and older who had undergone CABG and were in The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (n = 504,596) from 2011 to 2018 were linked to Centers for Medicare and Medicaid Service data to assess long-term survival. The association of intraoperative anemia defined by intraoperative nadir hematocrit (nHct) and red blood cell (RBC) transfusions, and their interactions, on long-term mortality were assessed with Kaplan-Meier estimates and multivariable Cox regression. Restricted cubic splines were used to explore the association between nHct as a continuous variable and long-term mortality.

RESULTS

258,398 on-pump CABG STS Adult Cardiac Surgery Database patients surviving the perioperative period were linked to Centers for Medicare and Medicaid Service claims files. Per World Health Organization criteria, 41% had preoperative anemia. Mean intraoperative nHct was 24%; RBC transfusion rate was 43.7%. Univariable analysis associated both RBC transfusion and lower nHct with worse survival. Lower nHct was only marginally associated with risk-adjusted mortality: adjusted hazard ratio (AHR) 1.04 (95% CI, 1.01-1.06) and 1.07 (95% CI, 1.00-1.14) at nHct 20% and at nHct 14%, respectively. RBC transfusion was associated with significantly higher adjusted mortality irrespective of timing of transfusion: AHR intraoperative 1.21 (95% CI, 1.18-1.27); AHR postoperative 1.26 (95% CI, 1.22-1.30); AHR both 1.46 (95% CI, 1.40-1.52) and across all levels of nHct. RBC transfusion was not associated with improved survival at any level of nHct.

CONCLUSIONS

Among Medicare CABG patients, RBC transfusions were associated with increased risk-adjusted late mortality across all levels of nHct whereas intraoperative anemia was only marginally so. Tolerance of lower intraoperative nHct than currently accepted may be preferable to transfusions.

Anemia is associated with higher mortality and morbidity after thoracic endovascular aortic repair

BACKGROUND

It is uncertain whether preoperative anemia is independently associated with thoracic endovascular aortic repair (TEVAR) outcomes. Using a national vascular surgery database, we evaluated the associations between preoperative anemia and 30-day mortality, postoperative complications, and 1-year survival for patients undergoing TEVAR.

METHODS

We retrospectively analyzed all patients in the Vascular Quality Initiative who had undergone TEVAR for aortic dissection, aortic aneurysm, penetrating aortic ulcer, hematoma, or thrombus between January 2011 and December 2019. We excluded patients with a ruptured aneurysm, traumatic dissection, emergent repair, treated aorta distal to zone 5, polycythemia, transfusion of >4 U of packed red blood cells intraoperatively or postoperatively, and missing data on hemoglobin level or surgical indications. The final study cohort was dichotomized into two groups: normal/mild anemia (women, ≥10 g/dL; men, ≥12 g/dL) and moderate/severe anemia (women, <10 g/dL; male, <12 g/dL). Propensity scores by stratification were used to control for confounding in the analysis of the association between the outcomes of 30-day mortality, postoperative complications, and 1-year survival and a binary indicator variable of moderate/severe anemia vs normal/mild anemia. Kaplan-Meier analysis and log-rank tests were used to compare the 1-year survival between the two groups. A Cox regression model was fitted to assess the associations between anemia and survival outcomes.

RESULTS

A total of 3391 patients were analyzed, 958 (28.3%) of whom had had moderate/severe anemia. After adjustment for multiple clinical factors using propensity score stratification, moderate/severe anemia was associated with a 141% increased odds of 30-day mortality (adjusted odds ratio [aOR], 2.41; 95% confidence interval [CI], 1.15-5.05; P = .019), 58% increased odds of any in-hospital complication (aOR, 1.58; 95% CI, 1.17-2.13; P = .003), 281% increased odds of intraoperative transfusion (aOR, 3.81; 95% CI, 2.68-5.53; P < .001). In addition, moderate/severe anemia was associated with significantly worse survival within the first year after TEVAR (log-rank P < .001; 1-year survival rate using Kaplan-Meier estimates, 86.4% ± 1.3% standard error vs 92.5% ± 0.6% standard error) and with an increased risk of mortality in the first postoperative year (adjusted hazard ratio, 1.81; 95% CI, 1.16-2.82; P = .009).

CONCLUSIONS

We found that moderate or severe anemia is associated with significantly increased odds of mortality, postoperative complications, and worse 1-year survival after TEVAR. Future studies are needed to evaluate the effect of anemia correction on the outcomes of TEVAR.

Multicentre randomised trials in anaesthesia: an analysis using Bayesian metrics

Are the results of randomised trials reliable and are p values and confidence intervals the best way of quantifying efficacy? Low power is common in medical research, which reduces the probability of obtaining a 'significant result' and declaring the intervention had an effect. Metrics derived from Bayesian methods may provide an insight into trial data unavailable from p values and confidence intervals. We did a structured review of multicentre trials in anaesthesia that were published in the New England Journal of Medicine, The Lancet, Journal of the American Medical Association, British Journal of Anaesthesia and Anesthesiology between February 2011 and November 2021. We documented whether trials declared a non-zero effect by an intervention on the primary outcome. We documented the expected and observed effect sizes. We calculated a Bayes factor from the published trial data indicating the probability of the data under the null hypothesis of zero effect relative to the alternative hypothesis of a non-zero effect. We used the Bayes factor to calculate the post-test probability of zero effect for the intervention (having assumed 50% belief in zero effect before the trial). We contacted all authors to estimate the costs of running the trials. The median (IQR [range]) hypothesised and observed absolute effect sizes were 7% (3-13% [0-25%]) vs. 2% (1-7% [0-24%]), respectively. Non-zero effects were declared for 12/56 outcomes (21%). The Bayes factor favouring a zero effect relative to a non-zero effect for these 12 trials was 0.000001-1.9, with post-test zero effect probabilities for the intervention of 0.0001-65%. The other 44 trials did not declare non-zero effects, with Bayes factors favouring zero effect of 1-688, and post-test probabilities of zero effect of 53-99%. The median (IQR [range]) study costs reported by 20 corresponding authors in US$ were $1,425,669 ($514,766-$2,526,807 [$120,758-$24,763,921]). We think that inadequate power and mortality as an outcome are why few trials declared non-zero effects. Bayes factors and post-test probabilities provide a useful insight into trial results, particularly when p values approximate the significance threshold.

Effectiveness of clinical decision support in controlling inappropriate red blood cell and platelet transfusions, speciality specific responses and behavioural change

BACKGROUND

Electronic clinical decision support (CDS) within Electronic Health Records has been used to improve patient safety, including reducing unnecessary blood product transfusions. We assessed the effectiveness of CDS in controlling inappropriate red blood cell (RBC) and platelet transfusion in a large acute hospital and how speciality specific behaviours changed in response.

METHODS

We used segmented linear regression of interrupted time series models to analyse the instantaneous and long term effect of introducing blood product electronic warnings to prescribers. We studied the impact on transfusions for patients in critical care (CC), haematology/oncology (HO) and elsewhere.

RESULTS

In non-CC or HO, there was significant and sustained decrease in the numbers of RBC transfusions after introduction of alerts. In CC the alerts reduced transfusions but this was not sustained, and in HO there was no impact on RBC transfusion. For platelet transfusions outside of CC and HO, the introduction of alerts stopped a rising trend of administration of platelets above recommended targets. In CC, alerts reduced platelet transfusions, but in HO alerts had little impact on clinician prescribing.

CONCLUSION

The findings suggest that CDS can result in immediate change in user behaviour which is more obvious outside specialist settings of CC and HO. It is important that this is then sustained. In CC and HO, blood transfusion practices differ. CDS thus needs to take specific circumstances into account. In this case there are acceptable reasons to transfuse outside of these crude targets and CDS should take these into account.

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.

Perioperative Management of the Patient at High-Risk for Cardiac Surgery-Associated Acute Kidney Injury

Acute kidney injury (AKI) is one of the most common major complications of cardiac surgery, and is associated with increased morbidity and mortality. Cardiac surgery-associated AKI has a complex, multifactorial etiology, including numerous factors such as primary cardiac dysfunction, hemodynamic derangements of cardiac surgery and cardiopulmonary bypass, and the possibility of a large volume of blood transfusion. There are no truly effective pharmacologic therapies for the management of AKI, and, therefore, anesthesiologists, intensivists, and cardiac surgeons must remain vigilant and attempt to minimize the risk of developing renal dysfunction. This narrative review describes the current state of the scientific literature concerning the specific aspects of cardiac surgery-associated AKI, and presents it in a chronological fashion to aid the perioperative clinician in their approach to this high-risk patient group. The evidence was considered for risk prediction models, preoperative optimization, and the intraoperative and postoperative management of cardiac surgery patients to improve renal outcomes.

Predictive role of the neutrophil: lymphocyte ratio in acute kidney injury associated with off-pump coronary artery bypass grafting

OBJECTIVES

This study aims to investigate whether the ratios of cell types in peripheral blood could be used as reliable predictors of off-pump coronary artery bypass grafting (CABG)-associated acute kidney injury (AKI).

MATERIALS AND METHODS

We retrospectively reviewed patients (n = 420) undergoing off-pump CABG from January 1, 2021 to January 1, 2022 in Qilu Hospital of Shandong University. We used logistic regression analysis to identify the potential predictors of off-pump CABG-associated AKI and construct a predictive model. Receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive ability of predictors and prediction models.

RESULTS

The prevalence of AKI associated with off-pump CABG was 20.95%. Patients in the AKI group had significantly higher ratios of peripheral blood cells on postoperative day (POD)1 than patients in the non-AKI group (P < 0.01). The area under the ROC curve (AUC) of the neutrophil:lymphocyte ratio (NLR) on POD1 for predicting off-pump CABG-associated AKI was 0.780 and the cutoff value was 20.07. Patients with high NLR on POD1 had a poor short-term prognosis. The AUC of the predictive model constructed by logistic regression analysis was 0.882. The sensitivity was 68.2% and the specificity was 93.1%.

CONCLUSION

The NLR on POD1 was a reliable predictive biomarker of off-pump CABG-associated AKI. And we successfully construct a prediction model, which contribute to the early recognition and management of off-pump CABG-associated AKI.