Prediction of massive blood transfusion in cardiac surgery

Impact of intraoperative therapeutic plasma exchange on bleeding in lung transplantation

BACKGROUND

Our program uses a desensitization protocol that includes intraoperative therapeutic plasma exchange (iTPE) for crossmatch-positive lung transplants, which improves access to lung transplant for sensitized candidates while mitigating immunologic risk. Although we have reported excellent outcomes for sensitized patients with the use of this protocol, concern for perioperative bleeding appears to have hindered broader adoption of it at other programs. We conducted a retrospective cohort study to quantify the impact of iTPE on perioperative bleeding in lung transplantation.

METHODS

All first-time lung transplant recipients from 2014 to 2019 who received iTPE were compared to those who did not. Multivariable logistic regression was used to determine the association between iTPE and large-volume perioperative transfusion requirements (≥5 packed red blood cell units within 24 hours of transplant start), adjusted for disease type, transplant type, and extracorporeal membrane oxygenation or cardiopulmonary bypass use. The incidence of hemothorax (requiring reoperation within 7 days of lung transplant) and 30-day posttransplant mortality were compared between the 2 groups using chi-square test.

RESULTS

One hundred forty-two patients (16%) received iTPE, and 755 patients (84%) did not. The mean number of perioperative pRBC transfusions was 4.2 among patients who received iTPE and 2.9 among patients who did not. iTPE was associated with increased odds of requiring large-volume perioperative transfusion (odds ratio 1.9; 95% confidence interval: 1.2-2.9, p-value = 0.007) but was not associated with an increased incidence of hemothorax (5% in both groups, p = 0.99) or 30-day posttransplant mortality (3.5% among patients who received iTPE vs 2.1% among patients who did not, p = 0.31).

CONCLUSIONS

This study demonstrates that the use of iTPE in lung transplantation may increase perioperative bleeding but not to a degree that impacts important posttransplant outcomes.

Use of Aprotinin versus Tranexamic Acid in Cardiac Surgery Patients with High-Risk for Excessive Bleeding (APACHE) trial: a multicentre retrospective comparative non-randomized historical study

OBJECTIVES

Following the reintroduction of aprotinin into the European market, the French Society of Cardiovascular and Thoracic Anaesthesiologists recommended its prophylactic use at half-dose for high-risk cardiac surgery patients. We examined whether the use of aprotinin instead of tranexamic acid could significantly reduce severe perioperative bleeding.

METHODS

This multicentre, retrospective, historical study included cardiac surgery patients treated with aprotinin or tranexamic acid between December 2017 and September 2020. The primary efficacy end point was the severe or massive perioperative bleeding (class 3-4 of the universal definition of perioperative bleeding). The safety secondary end points included the occurrence of thromboembolic events and all-cause mortality within 30 days after surgery.

RESULTS

Among the 693 patients included in the study, 347 received aprotinin and 346 took tranexamic acid. The percentage of patients with severe or massive bleeding was similar in the 2 groups (42.1% vs 43.6%, Adjusted odds ratio [ORadj] = 0.87, 95% confidence interval: 0.62-1.23, P = 0.44), as was the perioperative need for blood products (81.0% vs 83.2%, ORadj = 0.75, 95% confidence interval: 0.48-1.17, P = 0.20). However, the median (Interquartile range) 12 h postoperative blood loss was significantly lower in the aprotinin group (383 ml [241-625] vs 450 ml [290-730], P < 0.01). Compared to tranexamic acid, the intraoperative use of aprotinin was associated with increased risk for thromboembolic events (adjusted Hazard ratio 2.30 [95% Cl: 1.06-5.30]; P = 0.04).

CONCLUSIONS

Given the modest reduction in blood loss at the expense of a significant increase in thromboembolic adverse events, aprotinin use in high-risk cardiac surgery patients should be based on a carefully considered benefit-risk assessment.

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.

Dose-dependent influence of red blood cell transfusion volume on adverse outcomes in cardiac surgery

INTRODUCTION

Red blood cell (RBC) transfusion is associated with adverse outcomes, but there are few studies on the RBC volume. This study aimed to evaluate the relationship between intraoperative RBC volume and postoperative adverse outcomes for on-pump cardiac surgery.

METHODS

Adult patients undergoing on-pump cardiac surgery from 1 January 2017 to 31 December 2018 were included. Those transfused with more than 6 units of RBC were excluded. The clinical characteristics of four groups with various RBC volume were compared. We analyzed the relationship between RBC volume and adverse outcomes through multivariable logistic regression.

RESULTS

12,143 patients were analyzed, of which 3353 (27.6%) were transfused with 1-6U RBC intraoperatively. The incidence of death, overall morbidity, acute kidney injury and prolonged mechanical ventilation were increased stepwise along with incremental RBC volume. After adjusting for possible confounders, patients transfused with 1-2U were associated with a 1.42-fold risk of death (99% CI, 1.21-2.34, p = 0.01) compared with patients without RBC, patients with 3-4U were associated with a 1.57-fold risk (99% CI, 1.32-2.80, p = 0.005) and patients with 5-6U had a 2.26-fold risk of death (99% CI, 1.65-3.88, p < 0.001). Similarly, the incidence of overall morbidity, acute kidney injury and prolonged mechanical ventilation increased several folds as the RBC numbers increased.

CONCLUSIONS

There was a significant dose-dependent influence of incremental intraoperative RBC volume on increased risk of adverse outcomes for on-pump cardiac surgery patients. Patient blood management practice should aim to reduce not only transfusion rate but also the volume of blood use.

Perioperative Complications in Infective Endocarditis

Infective endocarditis is a challenging condition to manage, requiring collaboration among various medical professionals. Interdisciplinary teamwork within endocarditis teams is essential. About half of the patients diagnosed with the disease will ultimately have to undergo cardiac surgery. As a result, it is vital for all healthcare providers involved in the perioperative period to have a comprehensive understanding of the unique features of infective endocarditis, including clinical presentation, echocardiographic signs, coagulopathy, bleeding control, and treatment of possible organ dysfunction. This narrative review provides a summary of the current knowledge on the incidence of complications and their management in the perioperative period in patients with infective endocarditis.

Development of a Novel Prediction Model for Red Blood Cell Transfusion Risk in Cardiac Surgery

BACKGROUND

Cardiac surgery is a complex and invasive procedure that often requires blood transfusions to replace the blood lost during surgery. Blood products are a scarce and expensive resource. Therefore, it is essential to develop a standardized approach to determine the need for blood transfusions in cardiac surgery. The main objective of our study is to develop a simple prediction model for determining the risk of red blood cell transfusion in cardiac surgery.

METHODS

Retrospective cohorts of adult patients who underwent cardiac surgery between 2017 and 2019 were studied to identify hypothetical predictors of blood transfusion. Finally, a multivariable logistic regression model was developed to predict the risk of transfusion in cardiac surgery using the AUC and the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

We included 1234 patients who underwent cardiac surgery. Of the entire cohort, 875 patients underwent a cardiac procedure 69.4% [CI 95% (66.8%; 72.0%)]; 119 patients 9.6% [CI 95% (8.1%; 11.4%)] underwent a combined procedure, and 258 patients 20.9% [CI 95% (18.7; 23.2)] underwent other cardiac procedures. The median perioperative hemoglobin was 13.0 mg/dL IQR (11.7; 14.2). The factors associated with the risk of transfusion were age > 60 years OR 1.37 CI 95% (1.02; 1.83); sex female OR 1.67 CI 95% (1.24; 2.24); BMI > 30 OR 1.46 (1.10; 1.93); perioperative hemoglobin < 14 OR 2.11 to 51.41 and combined surgery OR 3.97 CI 95% (2.19; 7.17). The final model shows an AUC of 80.9% for the transfusion risk prediction [IC 95% (78.5-83.3%)]; p < 0.001].

CONCLUSIONS

We have developed a model with good discriminatory ability, which is more parsimonious and efficient than other models.

Factors associated with deep sternal wound infection after open-heart surgery in a Danish registry

Objective

To conduct a comprehensive multivariate analysis of variables associated with deep sternal wound infection, after open-heart surgery via median sternotomy.

Method

A retrospective cohort of all adult patients, who underwent open-heart surgery at Odense University Hospital between 01-01-2000 and 31-12-2020 was extracted from the West Danish Heart Registry. Data were analyzed using maximum likelihood logistic regression.

Results

A total of 15,424 patients underwent open-heart surgery and 244 developed a deep sternal wound infection, equivalent to 1,58 %. After data review 11,182 entries were included in the final analysis, of which 189 developed DSWI, equivalent to 1,69 %. Multivariate analysis found the following variables to be associated with the development of deep sternal wound infection (odds ratios and 95%confidens intervals in parentheses): Known arrhythmia (1.70; 1.16-2.44), Left Ventricular Ejection Fraction (1.66; 1.02-2.58), Body Mass Index 25-30 (1.66; 1.12-2.52), Body Mass Index 30-35 (2.35; 1.50-3.71), Body Mass Index 35-40 (3.61; 2.01-6.33), Body Mass Index 40+ (3.70; 1.03-10.20), Age 60-69 (1.64; 1.04-2.67), Age 70-79 (1.95; 1.23-3.19), Chronic Obstructive Pulmonary Disease (1.77; 1.21-2.54), Reoperation (1.63; 1.06-2.45), Blood transfusion in surgery (1.09; 1.01-1.17), Blood transfusion in intensive care unit (1.03; 1.01-1.06), Known peripheral atherosclerosis (1.82; 1.25-2.61), Current smoking (1.69; 1.20-2.35), Duration of intubation (1.33; 1.12-1.57).

Conclusion

Increased risk of deep sternal wound infection after open-heart surgery is a multifactorial problem, while some variables are unchangeable others are not. Focus should be on optimizing the condition of the patient prior to surgery e.g. weight loss and smoking. But also factors surrounding the patient e.g. preventing blood loss and minimizing intubation time.

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.

Systematic review highlights high risk of bias of clinical prediction models for blood transfusion in patients undergoing elective surgery

BACKGROUND

Blood transfusion can be a lifesaving intervention after perioperative blood loss. Many prediction models have been developed to identify patients most likely to require blood transfusion during elective surgery, but it is unclear whether any are suitable for clinical practice.

STUDY DESIGN AND SETTING

We conducted a systematic review, searching MEDLINE, Embase, PubMed, The Cochrane Library, Transfusion Evidence Library, Scopus, and Web of Science databases for studies reporting the development or validation of a blood transfusion prediction model in elective surgery patients between January 1, 2000 and June 30, 2021. We extracted study characteristics, discrimination performance (c-statistics) of final models, and data, which we used to perform risk of bias assessment using the Prediction model risk of bias assessment tool (PROBAST).

RESULTS

We reviewed 66 studies (72 developed and 48 externally validated models). Pooled c-statistics of externally validated models ranged from 0.67 to 0.78. Most developed and validated models were at high risk of bias due to handling of predictors, validation methods, and too small sample sizes.

CONCLUSION

Most blood transfusion prediction models are at high risk of bias and suffer from poor reporting and methodological quality, which must be addressed before they can be safely used in clinical practice.

Blood transfusion in aortic root surgery impairs midterm survival

Objective

To evaluate the effect of perioperative allogeneic packed red blood cell (RBC) transfusion during aortic root replacement.

Method

We reviewed patients undergoing aortic root replacement at our institution between March 2014 and April 2020. In total, 760 patients underwent aortic root replacement, of whom 442 (58%) received a perioperative RBC transfusion. Propensity score matching was used to account for baseline and operative differences resulting in 159 matched pairs. All-cause mortality was assessed with Kaplan-Meier curves. Data were obtained from our institutional Society of Thoracic Surgeons database and chart review.

Results

After propensity score matching, the RBC-transfused and -nontransfused groups were similar for all preoperative characteristics. Cardiopulmonary bypass time, crossclamp time, and lowest operative temperature were similar between the transfused and nontransfused groups (standardized mean difference <0.05). RBC transfusion was associated with more frequent postoperative ventilation greater than 24 hours (36/159 [23%] vs 19/159 [12%]; P = .01), postoperative hemodialysis (9/159 [5.7%] vs 0/159 [0%]; P = .003), reoperation for mediastinal hemorrhage (9/159 [5.7%] vs 0/159 [0%]; P = .003), and longer intensive care unit and hospital length of stay (3 vs 2 days and 8 vs 6 days respectively; P < .001). Thirty-day operative mortality after propensity score matching was similar between the cohorts (1.9%; 3/159 vs 0%; P = .2), and 5-year survival was reduced in the RBC transfusion cohort (90.2% [95% confidence interval, 84.1%-96.7%] vs 97.1% [95% confidence interval, 92.3%-100%] P = .035).

Conclusions

Aortic root replacement frequently requires RBC transfusion during and after the operation, but even after matching for observed preoperative and operative characteristics, RBC transfusion is associated with more frequent postoperative complications and reduced midterm survival.

Patients with infective endocarditis undergoing cardiac surgery have distinct ROTEM profiles and more bleeding complications compared to patients without infective endocarditis

BACKGROUND

The coagulation system is crucial in the pathogenesis of infective endocarditis and undergoes significant changes during course of the disease. However, little is known about the implications of those changes in the perioperative period. Aim of the present study was to delineate the specific coagulation patterns and their clinical consequence in patients undergoing cardiac surgery due to infective endocarditis.

METHODS

In this single-centre, exploratory, prospective observational study, we investigated the incidence and degree of coagulopathy in patients with (n = 31) and without infective endocarditis (n = 39) undergoing cardiac valve surgery. The primary outcome was the differences between these two groups in rotational thromboelastometry (ROTEM) results before, during and after surgery. The secondary outcomes were the differences between the groups in heparin sensitivity, bleeding complications, and transfusion requirements.

RESULTS

Most ROTEM parameters in EXTEM, INTEM and FIBTEM assays were significantly altered in patients with infective endocarditis. Clotting time in the EXTEM assay was significantly prolonged in the endocarditis group at all time-points, while all clot firmness parameters (A5, A10 and MCF) were significantly increased. The heparin sensitivity index was significantly lower in the endocarditis group (median index 0.99 vs 1.17s. IU-1.kg-1, p = .008), indicating increased heparin resistance. Patients with infective endocarditis had more bleeding complications as assessed by the universal definition of perioperative bleeding score (OR 3.0, p = .018), and more patients with endocarditis underwent early re-exploration (p = .018).

CONCLUSIONS

The findings of this exploratory investigation show significantly altered coagulation profiles in patients with infective endocarditis, with concomitant hyper- and hypocoagulability. Furthermore, the incidence of bleeding complications and transfusion requirements were increased in patients with endocarditis. These results show the potential of ROTEM to detect coagulation abnormalities in patients with infective endocarditis. Existing point-of-care coagulation testing guided algorithms for optimizing perioperative coagulation management possibly need to be adjusted for these high-risk patients undergoing cardiac surgery.

Impact of a Hemoglobin Trigger Communication Tool on Perioperative Transfusion in Cardiac Surgery

OBJECTIVES

Blood transfusion represents an important and potentially modifiable risk in the daily practice of cardiac surgery. The risk profile and increasing cost of transfusion led us to study the effect of different maneuvers, interventions, or surgical techniques to minimize transfusion while maintaining patient safety. This study compares postoperative outcomes before and after incorporating a verbal hemoglobin (Hb) trigger during the surgical timeout in which the surgeon and anesthesiologist preemptively agree on a threshold for packed red blood cell (PRBC) administration in the perioperative period.

METHODS

The authors performed a chart review of patients who underwent cardiac surgery from July 2013 through June 2014 at our institution. Patients who underwent surgery from July 2013 through December 2013 served as the pre-Hb trigger group, and patients who underwent surgery from January 2014 through June 2014 served as the post-Hb trigger group. Information collected included patient demographics, type of cardiac surgery, preoperative Hb, Hb trigger, and intraoperative and postoperative variables. The primary outcome was the incidence of PRBC transfusions. Secondary outcomes included the incidence of frozen plasma (FP) transfusion, mechanical ventilation beyond postoperative day 1, and 30-day mortality.

RESULTS

The study included 191 patients, with 84 in the pre-Hb trigger group and 107 in the post-Hb trigger group. Intraoperative PRBC transfusions did not decrease in the posttrigger group compared with the pretrigger group (pretrigger 51.4% vs posttrigger 52.4%, P = 1.0); however, intraoperative FP administration was lower in the posttrigger group (65.4% vs 50.0%, P = 0.038). Postoperative mechanical ventilation beyond postoperative day 1 also was significantly lower in the posttrigger group compared with the pretrigger group (27.1% vs 14.3%, P = 0.035).

CONCLUSIONS

Implementation of a verbal Hb trigger during the surgical timeout was associated with a reduction in FP administration and duration of mechanical ventilation, but not a decrease in PRBC transfusion and mortality.

The use of FEIBA for refractory bleeding in cardiac surgery - a systematic review

INTRODUCTION

Significant blood loss during cardiac surgery is associated with a significant increase in morbidity and mortality. Factor Eight Inhibitor Bypassing Activity (FEIBA), a hemostatic bypassing agent mainly used in hemophiliac patients, has also been used for intractable surgical bleeding during cardiac surgical procedures in non-hemophiliac patients. However, concerns exist that its use may be linked to increased incidence of perioperative adverse effects including thrombotic complications.

AREAS COVERED

A systematic literature search was performed on MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases for all studies that reported the administration of FEIBA for treatment of bleeding during adult cardiac surgery in non-hemophiliac patients. After selecting of title and abstracts, two authors assessed the methodological quality of the full-text articles prior to final inclusion in the manuscript.

EXPERT OPINION

The safety profile of FEIBA was determined through an aggregate count of adverse events. Major complications included renal failure, re-operation for unresolved bleeding, postoperative mortality, and thromboembolic events. Overall, there is insufficient robust evidence to make a definitive conclusion about the safety or efficacy of using of FEIBA as a hemostatic agent in the setting of cardiac surgery.

Preoperative patient factors associated with blood product use in cardiac surgery, a retrospective cohort study

BACKGROUND

Cardiac surgery is associated with a high rate of blood use. The aim of this study is to identify preoperative patient factors associated with allogeneic Red Blood Cell (RBC) or non-Red Blood Cell (NRBC) use in cardiac surgery.

METHODS

All adult cardiac surgical procedures conducted at a single Western Australian institution were retrospectively analysed. Data was collected from the Australia and New Zealand Cardiac Surgery Database from 2015 to 2018. A number of preoperative factors were identified, relating to past medical history or preoperative cardiac status. Outcome 1 was defined as the use of one or more RBC products intra or post-operatively. Outcome 2 was defined as the use of one or more NRBC products intra or post-operatively. Multivariate logistical regression analysis was done to assess for the association between preoperative factors and allogeneic blood product use.

RESULTS

A total of 1595 patients were included in this study, of which 1488 underwent a Coronary Artery Bypass Graft, Valve or a combined procedure. Patients on dialysis preoperatively and those who had preoperative cardiogenic shock demonstrated the greatest risk of requiring RBC transfusion with an odds ratio of 5.643 (95% CI 1.305-24.40) and 3.257 (95% 1.801-5.882) respectively. Patients who had preoperative cardiogenic shock demonstrated the greatest risk of requiring NRBC transfusion with an odds ratio of 3.473 (95% CI 1.970-6.135). Patients who have had a previous cardiothoracic intervention are at increased risk of both RBC and NRBC transfusion, with adjusted odds ratios of 1.774 (95% CI 1.353-2.325) and 2.370 (95% CI 1.748-3.215) respectively.

CONCLUSION

A number of factors relating to past medical history or preoperative cardiac status are implicated with increased allogeneic blood product use in cardiac surgery. Identifying high-risk patients in a preoperative setting can enable us enrol them in a blood conservation program, therefore minimizing the risk of exposure to blood transfusion.

Anesthesia Considerations in Infective Endocarditis

The management of infective endocarditis is complex and inherently requires multidisciplinary cooperation. About half of all patients diagnosed with infective endocarditis will meet the criteria to undergo cardiac surgery, which regularly takes place in urgent or emergency settings. The pathophysiology and clinical presentation of infective endocarditis make it a unique disorder within cardiac surgery that warrants a thorough understanding of specific characteristics in the perioperative period. This includes, among others, echocardiography, coagulation, bleeding management, or treatment of organ dysfunction. In this narrative review article, the authors summarize the current knowledge on infective endocarditis relevant for the clinical anesthesiologist in perioperative management of respective patients. Furthermore, the authors advocate for the anesthesiologist to become a structural member of the endocarditis team.

Development and validation of a machine learning method to predict intraoperative red blood cell transfusions in cardiothoracic surgery

Accurately predicting red blood cell (RBC) transfusion requirements in cardiothoracic (CT) surgery could improve blood inventory management and be used as a surrogate marker for assessing hemorrhage risk preoperatively. We developed a machine learning (ML) method to predict intraoperative RBC transfusions in CT surgery. A detailed database containing time-stamped clinical variables for all CT surgeries from 5/2014-6/2019 at a single center (n = 2410) was used for model development. After random forest feature selection, surviving features were inputs for ML algorithms using five-fold cross-validation. The dataset was updated with 437 additional cases from 8/2019-8/2020 for validation. We developed and validated a hybrid ML method given the skewed nature of the dataset. Our Gaussian Process (GP) regression ML algorithm accurately predicted RBC transfusion amounts of 0 and 1-3 units (root mean square error, RMSE 0.117 and 1.705, respectively) and our GP classification ML algorithm accurately predicted 4 + RBC units transfused (area under the curve, AUC = 0.826). The final prediction is the regression result if classification predicted < 4 units transfused, or the classification result if 4 + units were predicted. We developed and validated an ML method to accurately predict intraoperative RBC transfusions in CT surgery using local data.

Risk Factors for High Blood Product Use in Patients with Stanford Type A Dissection

BACKGROUND

 Intraoperative and postoperative bleeding associated with allogeneic blood transfusion and reoperation is still a common and feared complication in patients undergoing surgery due to acute Type A Aortic Dissection (aTAAD). The aim of our study was to identify risk factors for higher transfusion rates.

METHODS

 In this retrospective single center study we evaluated pre -, intra-, and postoperative data of 121 patients with aTAAD. Depending on the median of received packed red blood cells (PRBCs), patients were divided into Group A (<8 PRBC, n = 53) and Group B (≥8 PRBC n = 68). Statistical analyses (descriptive statistics, univariable and multivariable logistic regression) were performed using SPSS software 25.0. Statistical significance was assumed at p-value <0.05.

RESULTS

 A total of 120 patients received a blood product during their perioperative course. Among others we identified age, hemorrhagic pericardial effusion, and dual antiplatelet therapy as preoperative risk factors, low rectal temperature as intraoperative risk factor and low body temperature, positive fluid balance, high lactate level and beginning development of acute renal failure as postoperative risk factors.

CONCLUSION

 Our study identifies several factors which predict a higher likelihood of bleeding and consecutive blood transfusion. Knowledge of these factors could influence the therapy to reduce transfusion requirements and lead to a targeted and more efficient use of coagulation products.

Incidence and risk factors of acute cholecystitis after cardiovascular surgery

OBJECTIVES

Acute cholecystitis is a complication in critically ill patients. However, a few studies have described its incidence, risk factors, and mortality in patients who underwent cardiovascular surgery. We investigated the incidence, perioperative predictors, and clinical features of acute cholecystitis after cardiovascular surgery.

METHODS

This retrospective cohort study examined 7013 patients who underwent cardiovascular surgery between October 2000 and March 2019 at a tertiary care hospital. We collected preoperative, intraoperative, and postoperative data from our database and electronic medical records. The primary outcome was the incidence of postoperative cholecystitis until hospital discharge. A multivariable logistic regression analysis to estimate perioperative predictors of acute cholecystitis was conducted. We described the clinical characteristics of patients complicated with acute cholecystitis.

RESULTS

Among the 7013 patients, 51 (0.7%) developed acute cholecystitis. Logistic regression analysis found that circulatory arrest (odds ratio [OR] 1.97; 95% confidence interval [CI] 1.04-3.74; P = 0.037) and intraoperative massive transfusion (OR 2.03; 95% CI 1.03-4.01; P = 0.041) were associated with the incidences of cholecystitis. In-hospital mortality was significantly higher in the cholecystitis group than in the non-cholecystitis group (13.7% vs 3.9%, P = 0.004). Aortic disease was more frequent in the cholecystitis group (54.9% vs 38.6%, P = 0.021). The median time of acute cholecystitis onset from surgery was 12.5 days (interquartile range 7.0-27.75). Twenty-six patients (51.0%) developed asymptomatic cholecystitis.

CONCLUSIONS

Approximately 1% of patients who underwent cardiovascular surgery developed postoperative cholecystitis; half of them were asymptomatic. Since cholecystitis is associated with high mortality, it is a complication after cardiovascular surgery that needs to be considered.

Preoperative anemia and transfusion in cardiac surgery: a single-centre retrospective study

Background

Preoperative anemia and transfusion are associated with worse outcomes. This study aims to identify the prevalence of preoperative anemia, transfusion rates on surgery day, and predictors of transfusion in elective cardiac surgery patients at our centre. We also aim to evaluate our preoperative intervention program, and examine the intervention window for anemia before surgery.

Methods

This study included 797 adult patients who underwent elective cardiac surgery at a tertiary hospital. Multivariable logistic regression analysis was used to identify predictors of transfusion on surgery day.

Results

Preoperative anemia was present in 15% of patients. Anemic patients had a significantly higher transfusion rate at 53% compared to 10% in non-anemic patients. Hemoglobin concentration, estimated glomerular filtration rate (eGFR), body surface area (BSA), and total cardiopulmonary bypass time were predictive of transfusion on surgery day. Patients had a median of 7 days between initial visit and surgery day, however, referral to the blood conservation clinic was only done for 8% of anemic patients and treatment was initiated in 3% of anemic patients. Among the 3 anemic patients who received treatment, 2 did not require blood transfusion on surgery day.

Conclusions

Preoperative anemia is present in 15% of patients at our centre and these patients have 53% transfusion rates on surgery day. Hemoglobin concentration, eGFR, BSA, and total cardiopulmonary bypass time were predictors of transfusion on surgery day. Patients had a median of 7 days between initial visit and surgery day. Referral and anemia treatment were infrequently initiated in preoperative anemic patient.

Rapid thrombelastography predicts perioperative massive blood transfusion in patients undergoing coronary artery bypass grafting: A retrospective study

Massive blood transfusion (MBT) is a relatively common complication of cardiac surgery, which is independently associated with severe postoperative adverse events. However, the value of using rapid thrombotomography (r-TEG) to predict MBT in perioperative period of cardiac surgery has not been explored. This study aimed to identify the effect of r-TEG in predicting MBT for patients undergoing coronary artery bypass grafting (CABG).This retrospective study included consecutive patients first time undergoing CABG at the Zhongnan Hospital of Wuhan University between March 2015 and November 2017. All the patients had done r-TEG tests before surgery. The MBT was defined as receiving at least 4 units of red blood cells intra-operatively and 5 units postoperatively (1 unit red blood cells from 200 mL whole blood).Lower preoperative hemoglobin level (P = .001) and longer cardiopulmonary bypass time (P = .001) were the independent risk factors for MBT during surgery, and no components of the r-TEG predicted MBT during surgery. Meanwhile, longer activated clotting time (P < .001), less autologous blood transfusion (P = .001), and older age (P = .008) were the independent risk factors for MBT within 24 hours of surgery.Preoperative r-TEG activated clotting time can predict the increase of postoperative MBT in patients undergoing CABG. We recommend the careful monitoring of coagulation system with r-TEG, which allows rapid diagnosis of coagulation abnormalities even before the start of surgery.

Transfusion characteristics and hemostatic conditions in octogenarians undergoing emergency surgery for acute aortic dissection: a retrospective study

Background

The number of elderly patients undergoing elective as well as emergent cardiac surgery is increasing. Octogenarian and older patients undergoing surgery for acute type A aortic dissection (AAD) have a significantly higher risk of postoperative mortality than younger patients. Hemostasis is difficult in octogenarians with AAD. However, few studies have investigated perioperative blood transfusion volumes and hemostatic conditions in patients undergoing AAD surgery. We retrospectively investigated whether these factors differed between octogenarians and younger patients with AAD.

Methods

The records of 207 patients who underwent emergency surgery for AAD were reviewed between 2008 and 2014. We compared the total volumes of transfused blood components (red blood cell concentrate, fresh frozen plasma, platelets concentrate, and cryoprecipitate), perioperative blood coagulation test results (prothrombin time-international normalized ratio, activated partial thrombin time, and activated coagulation time), and intensive care unit and hospital stay durations between octogenarians (n = 33) and patients < 80 years old (n = 170).

Results

A significantly greater volume of red blood cell concentrates was transfused in octogenarians than in patients < 80 years old. Isolated prolonged activated partial thromboplastin time was observed in octogenarian patients. Duration of hospital stays was significantly longer in octogenarians than in patients < 80 years old.

Conclusions

Octogenarians required more red blood cells during surgery for AAD and exhibited isolated APTT prolongation.

Are Blood Products Routinely Required in Pediatric Heart Surgery?

A restrictive blood transfusion strategy has emerged in adult cardiac surgery. However, the feasibility in children is poorly investigated. 352 consecutive patients undergoing open-heart surgery were retrospectively reviewed, excluding patients requiring extracorporeal membrane oxygenation. Patient demographics, perioperative blood product usage, and clinical outcome parameters were investigated. Variables predicting the need for blood products were delineated. Of the 352 study patients, 148 patients (42%) underwent bloodless surgery and 204 (58%) were transfused. Of the 204 transfused patients, 170 (83.4%) patients received one blood transfusion and 34 (16.6%) received two or more blood transfusions. Patient's weight and preoperative hematocrit (Hct) were statistically significant in predicting the need for blood priming the CPB circuit (AUC 0.99, p < 0.001, sensitivity 96.6%, specificity 95.2%). A body weight of 8.5 kg carried a sensitivity of 100% and specificity of 94.5% (p < 0.001) for a blood prime. Among patients with a weight less than 8.5 kg (n = 171), only 27 patients (15.8%, p < 0.001) required additional transfusion of PRBCs. Factors impacting the need for a blood transfusion during CPB included redo surgery [odds ratio (OR) 4.61, p = 0.001] and the highest lactate level on CPB (OR 1.65, p = 0.006). Redo surgery had the highest impact (OR 7.27, p = 0.012) for requiring a postoperative PRBC transfusion. A restrictive transfusion strategy can be safely implemented in pediatric cardiac surgery. The majority of children with a BW > 8.5 kg required no blood products and those with a BW ≤ 8.5 kg required only 1 unit of blood, to prime the cardiopulmonary bypass circuit.

Evaluation of risk scores in predicting perioperative blood transfusions in adult cardiac surgery

Objective:

Allogeneic blood product transfusions are associated with an increased morbidity and mortality risk in cardiac surgery. At present, a few transfusion risk scores have been proposed for cardiac surgery patients. The present study is aimed to develop a new score and to compare with preexisting scores – Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST) score.

Methodology:

A total of 1014 adult patients undergoing cardiac surgery were enrolled in the retrospective study. Independent predictors of allogeneic blood transfusions were selected from TRACK and TRUST scores. A predictive score was developed from six variables using logistic regression analysis, and new score was compared to the other existing scores – TRACK and TRUST.

Results:

The new score had following predictors: age >58 years, weight <63 kg for males and <49 kg for females, gender (female), complex surgery, hemoglobin <13.5 g/dl, and creatinine >1.36 mg/dl. Validation of new score demonstrated an acceptable predictive power (area under the curve [AUC] 0.749) and a good calibration at the Hosmer–Lemeshow test. New score was comparable with TRACK score with P = 0.578 (AUC of TRACK 0.756 and AUC of new score 0.749). There was a significant difference between new score and TRUST score, P = 0.01 (AUC of TRUST 0.72 and AUC of new score 0.749).

Conclusion:

New score is a simple risk model based on six predictors having a similar accuracy and calibration in predicting the transfusion rate in cardiac surgery as compared to TRACK score.

Risk of massive blood product requirement in cardiac surgery: A large retrospective study from 2 heart centers

Cardiac surgery under cardiopulmonary bypass (CPB) accounts for most consumption of red blood cells (RBCs). Identifying risk factors for massive red blood cell transfusion (MRT) in cardiac surgery may help to reduce this consumption.We retrospectively analyzed 8238 patients who underwent valve surgery and/or coronary artery bypass grafting (CABG) under CPB at 2 major heart centers in China. Uni- and multivariate logistic regression was carried out to assess whether risk factors for MRT (defined as receiving at least 4 units RBCs) varied with type of cardiac surgery.A total of 1691 patients (21%) received at least 4 units RBCs (6.77 ± 4.78 units per person). This MRT group consumed 70% of the total units of allogeneic RBCs in the study. MRT incidence was 2-fold higher among patients undergoing CABG with or without valve surgery than among patients undergoing valve surgery alone. Multivariate logistic analysis identified the following MRT risk factors common to valve surgery alone, CABG alone, and their combination: female sex, older age, renal dysfunction, lower body mass index, lower preoperative hemoglobin, and longer CPB. Several independent MRT risk factors were also identified specific to valve surgery: active endocarditis, nonatrial fibrillation, smaller left atrium diameter, abnormal international normalized ratio, and repeat surgery.Different types of cardiac surgery share several, but not all, MRT risk factors. This study may help guide the prediction and management of patients at higher MRT risk.

Comparison of Two Major Perioperative Bleeding Scores for Cardiac Surgery Trials

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Research into major bleeding during cardiac surgery is challenging due to variability in how it is scored. Two consensus-based clinical scores for major bleeding: the Universal definition of perioperative bleeding and the European Coronary Artery Bypass Graft (E-CABG) bleeding severity grade, were compared in this substudy of the Transfusion Avoidance in Cardiac Surgery (TACS) trial.

Methods

As part of TACS, 7,402 patients underwent cardiac surgery at 12 hospitals from 2014 to 2015. We examined content validity by comparing scored items, construct validity by examining associations with redo and complex procedures, and criterion validity by examining 28-day in-hospital mortality risk across bleeding severity categories. Hierarchical logistic regression models were constructed that incorporated important predictors and categories of bleeding.

Results

E-CABG and Universal scores were correlated (Spearman ρ = 0.78, P &lt; 0.0001), but E-CABG classified 910 (12.4%) patients as having more severe bleeding, whereas the Universal score classified 1,729 (23.8%) as more severe. Higher E-CABG and Universal scores were observed in redo and complex procedures. Increasing E-CABG and Universal scores were associated with increased mortality in unadjusted and adjusted analyses. Regression model discrimination based on predictors of perioperative mortality increased with additional inclusion of the Universal score (c-statistic increase from 0.83 to 0.91) or E-CABG (c-statistic increase from 0.83 to 0.92). When other major postoperative complications were added to these models, the association between Universal or E-CABG bleeding with mortality remained.

Conclusions

Although each offers different advantages, both the Universal score and E-CABG performed well in the validity assessments, supporting their use as outcome measures in clinical trials.

Preventing and managing catastrophic bleeding during extracorporeal circulation

The use of extracorporeal circulation for cardiac surgery and extracorporeal life support poses tremendous challenges to the hemostatic equilibrium given its diametric tendency to trigger hyper- and hypocoagulopathy. The necessity of anticoagulant therapy to counteract the hemostatic activation by the extracorporeal circuitry compounded by unfavorable patient and surgical factors significantly increase the risk of catastrophic bleeding in patients who require extracorporeal circulation. Preoperative measures, such as stratification of high-risk bleeding patients, and optimization of the modifiable variables, including anemia and thrombocytopenia, provide a crude estimation of the likelihood and may modify the risk of catastrophic bleeding. The anticipation for catastrophic bleeding subsequently prompts the appropriate preparation for potential resuscitation and massive transfusion. Equally important is intraoperative prevention with the prophylactic application of tranexamic acid, an antifibrinolytic agent that has promising benefits in reduction of blood loss and transfusion. In the event of uncontrolled catastrophic bleeding despite preemptive strategies, all effort must be centered on regaining hemostasis through surgical control and damage control resuscitation to protect against worsening coagulopathy and end organ failure. When control of bleeding is reinstated, management should shift focus from systemic therapy to targeted hemostatic therapy aimed at the potential culprits of coagulopathy as identified by point of care hemostatic testing. This review article outlines the strategies to appropriately intervene using prediction, prevention, preparation, protection, and promotion of hemostasis in managing catastrophic bleeding in extracorporeal circulation.

Rotational Thromboelastometry for Assessing Bleeding Complications and Factor XIII Deficiency in Cardiac Surgery Patients

We aimed to detect alterations and deficits in hemostasis during cardiac surgery with cardiopulmonary bypass (CPB) using point-of-care-supported coagulation analysis (rotational thromboelastometry, impedance aggregometry), in addition to single factor assays for the measurement of fibrinogen (FI) and factor XIII (FXIII) levels. Forty-one patients scheduled for elective cardiac surgery with CPB were enrolled in this observational study. Perioperative measurement (pre-, postheparin, 30-minutes before the end of bypass, 1-hourpostoperatively) of standard laboratory variables, additional rotational thromboelastometry (ROTEM; International GmbH, Munich, Germany), Multiplate analysis (Roche, Switzerland), and an assay of FXIII activity were performed as well as the collection of epidemiological data and blood loss. The FI and FXIII levels as well as the measured ROTEM and Multiplate parameters correlated weakly with the blood loss. Clotting time and maximum clot firmness (MCF) of the intrinsically activated ROTEM showed a good correlation (r_CT-INTEM = 0.378; P < .05, r_MCF-INTEM = 0.305; P < .05) with postoperative drainage loss, suggesting a dependence of blood loss on the initial intrinsic activity. Additionally, perioperative FI or FIBTEM levels and the FXIII levels correlated with each other. Intrinsically activated ROTEM showed a good correlation with postoperative drainage loss, thus suggesting a dependence of blood loss on the initial intrinsic activity and therefore facilitating clinicians to assess postoperative bleeding complications. Based on the FI level or the MCF_FIBTEM measured by ROTEM, it may also be possible to assess the FXIII concentration. Especially in chronically ill and massive bleeding cardiac surgery patients with significantly decreased FXIII levels, the knowledge of FXIII deficiency may help clinicians to treat coagulation disorders more adequately.

Protocol for a phase III, non-inferiority, randomised comparison of a new fibrinogen concentrate versus cryoprecipitate for treating acquired hypofibrinogenaemia in bleeding cardiac surgical patients: the FIBRES trial

INTRODUCTION

Coagulopathic bleeding is a serious complication of cardiac surgery to which an important contributor is acquired hypofibrinogenaemia (plasma fibrinogen <1.5-2.0 g/L). The standard intervention for acquired hypofibrinogenaemia is cryoprecipitate, but purified fibrinogen concentrates are also available. There is little comparative data between the two therapies and randomised trials are needed.

METHODS AND ANALYSIS

FIBrinogen REplenishment in Surgery (FIBRES) is a multicentre, randomised (1:1), active-control, single-blinded, phase III trial in adult cardiac surgical patients experiencing clinically significant bleeding related to acquired hypofibrinogenaemia. The primary objective is to demonstrate that fibrinogen concentrate (Octafibrin/Fibryga; Octapharma) is non-inferior to cryoprecipitate. All patients for whom fibrinogen supplementation is ordered by the clinical team within 24 hours of cardiopulmonary bypass will receive 4 g of fibrinogen concentrate or 10 units of cryoprecipitate (dose-equivalent to 4 g), based on random allocation and deferred consent. The primary outcome is total red cell, platelet and plasma transfusions administered within 24 hours of bypass. Secondary outcomes include major bleeding, fibrinogen levels and adverse events within 28 days. Enrolment of 1200 patients will provide >90% power to demonstrate non-inferiority. One preplanned interim analysis will include 600 patients. The pragmatic design and treatment algorithm align with standard practice, aiding adherence and generalisability.

ETHICS AND DISSEMINATION

The study is approved by the local research ethics board and will be conducted in accordance with the Declaration of Helsinki, Good Clinical Practice guidelines and regulatory requirements. Patient consent prior to treatment is waived, as per criteria in the Tri-Council Policy Statement. Results will be published in the scientific/medical literature, and at international congresses. Non-inferiority of purified fibrinogen concentrate would support its use in acquired hypofibrinogenaemia. The results are likely to improve care for cardiac surgical patients experiencing significant bleeding, an understudied yet high-risk population.

TRIAL REGISTRATION NUMBER

NCT03037424; Pre-results.

Hypothermia, pH, and Postoperative Red Blood Cell Transfusion in Massively Transfused Adult Cardiac Surgery Patients: A Retrospective Cohort Study

OBJECTIVE

To determine the relationships between hypothermia and pH at surgery end and postoperative red blood cell (RBC) transfusion in massively transfused adult cardiac surgery patients.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary care, academic medical center.

PARTICIPANTS

A total of 395 adult patients having cardiac surgery with cardiopulmonary bypass who were massively transfused during an 8-year period. Patients were excluded if they did not receive an antifibrinolytic drug during surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Body temperature and pH at surgery end were recorded. Postoperative RBC transfusion, a surrogate for postoperative bleeding, was the study's primary outcome. Secondary outcomes were postoperative fresh frozen plasma (FFP) transfusion, postoperative platelet transfusion, reoperation for bleeding, and mortality. Patients with hypothermia did not have more postoperative RBC transfusion (p = 0.56), but patients with acidosis or alkalosis received more RBCs after surgery (p = 0.04). There were no differences in secondary outcomes between groups. In multivariate analysis, both acidosis and alkalosis were independently associated with postoperative RBC transfusion (p = 0.01 and p < 0.0001).

CONCLUSION

Hypothermia at surgery end has no association with postoperative RBC transfusion in massively transfused cardiac surgery patients, but pH derangements are associated with increased postoperative transfusion. Thus, normalization of blood pH may be important in reducing postoperative bleeding in massively transfused cardiac surgery patients.

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery: systematic reviews, observational studies and randomised controlled trials

Background

Anaemia, coagulopathic bleeding and transfusion are strongly associated with organ failure, sepsis and death following cardiac surgery.

Objective

To evaluate the clinical effectiveness and cost-effectiveness of medical devices used as diagnostic and therapeutic tools for the management of anaemia and bleeding in cardiac surgery.

Methods and results

Workstream 1 – in the COagulation and Platelet laboratory Testing in Cardiac surgery (COPTIC) study we demonstrated that risk assessment using baseline clinical factors predicted bleeding with a high degree of accuracy. The results from point-of-care (POC) platelet aggregometry or viscoelastometry tests or an expanded range of laboratory reference tests for coagulopathy did not improve predictive accuracy beyond that achieved with the clinical risk score alone. The routine use of POC tests was not cost-effective. A systematic review concluded that POC-based algorithms are not clinically effective. We developed two new clinical risk prediction scores for transfusion and bleeding that are available as e-calculators. Workstream 2 – in the PAtient-SPecific Oxygen monitoring to Reduce blood Transfusion during heart surgery (PASPORT) trial and a systematic review we demonstrated that personalised near-infrared spectroscopy-based algorithms for the optimisation of tissue oxygenation, or as indicators for red cell transfusion, were neither clinically effective nor cost-effective. Workstream 3 – in the REDWASH trial we failed to demonstrate a reduction in inflammation or organ injury in recipients of mechanically washed red cells compared with standard (unwashed) red cells.

Limitations

Existing studies evaluating the predictive accuracy or effectiveness of POC tests of coagulopathy or near-infrared spectroscopy were at high risk of bias. Interventions that alter red cell transfusion exposure, a common surrogate outcome in most trials, were not found to be clinically effective.

Conclusions

A systematic assessment of devices in clinical use as blood management adjuncts in cardiac surgery did not demonstrate clinical effectiveness or cost-effectiveness. The contribution of anaemia and coagulopathy to adverse clinical outcomes following cardiac surgery remains poorly understood. Further research to define the pathogenesis of these conditions may lead to more accurate diagnoses, more effective treatments and potentially improved clinical outcomes.

Study registration

Current Controlled Trials ISRCTN20778544 (COPTIC study) and PROSPERO CRD42016033831 (systematic review) (workstream 1); Current Controlled Trials ISRCTN23557269 (PASPORT trial) and PROSPERO CRD4201502769 (systematic review) (workstream 2); and Current Controlled Trials ISRCTN27076315 (REDWASH trial) (workstream 3).

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 5, No. 17. See the NIHR Journals Library website for further project information.

Effects of 6% hydroxyethyl starch 130/0.4 on postoperative blood loss and kidney injury in off-pump coronary arterial bypass grafting: A retrospective study

We retrospectively evaluated the effects of 6% hydroxyethyl starch (HES) 130/0.4 on postoperative blood loss and acute kidney injury (AKI) in patients undergoing off-pump coronary artery bypass grafting (OPCAB).Electronic medical records of 771 patients who underwent OPCAB in our hospital between July 2012 and July 2014 were reviewed, and 249 patients without intraoperative HES-exposure (group NoHES) were matched 1:N with intraoperative HES-exposed 413 patients (group HES) based on propensity score. The effects of intraoperative HES on postoperative cumulative blood loss within the first 24 hours, need for bleeding-related reoperation, and occurrence of postoperative AKI (determined by KDIGO and RIFLE criteria) were analyzed.In our propensity score matched cohort, there were no significant differences between groups for median postoperative 24 hours blood loss (525 mL in group HES vs. 540 mL in group NoHES, P = .203) or need for bleeding-related reoperation (OR, 2.44; 95% confidence interval [CI], 0.64-9.34, P = .19). However, postoperative AKI (assessed by 2 criteria) occurred more frequently in group HES than in group NoHES (by KDIGO criteria: 10.7% vs. 3.6%; OR 3.43 [95% CI, 1.67-7.04]; P < .001 and by RIFLE criteria: 9.6% vs. 2%; OR 3.32 [95% CI, 1.34-8.24]; P = .01). The median volume of infused HES per patient weight was 16 mL/kg in group HES.In the patients undergoing OPCAB, intraoperative 6% HES 130/0.4 did not increase postoperative bleeding. However, renal safety remains a concern. Intraoperative use of HES should be determined cautiously during OPCAB.

Point-of-Care Hemostatic Testing in Cardiac Surgery: A Stepped-Wedge Clustered Randomized Controlled Trial

BACKGROUND

Cardiac surgery is frequently complicated by coagulopathic bleeding that is difficult to optimally manage using standard hemostatic testing. We hypothesized that point-of-care hemostatic testing within the context of an integrated transfusion algorithm would improve the management of coagulopathy in cardiac surgery and thereby reduce blood transfusions.

METHODS

We conducted a pragmatic multicenter stepped-wedge cluster randomized controlled trial of a point-of-care-based transfusion algorithm in consecutive patients undergoing cardiac surgery with cardiopulmonary bypass at 12 hospitals from October 6, 2014, to May 1, 2015. Following a 1-month data collection at all participating hospitals, a transfusion algorithm incorporating point-of-care hemostatic testing was sequentially implemented at 2 hospitals at a time in 1-month intervals, with the implementation order randomly assigned. No other aspects of care were modified. The primary outcome was red blood cell transfusion from surgery to postoperative day 7. Other outcomes included transfusion of other blood products, major bleeding, and major complications. The analysis adjusted for secular time trends, within-hospital clustering, and patient-level risk factors. All outcomes and analyses were prespecified before study initiation.

RESULTS

Among the 7402 patients studied, 3555 underwent surgery during the control phase and 3847 during the intervention phase. Overall, 3329 (45.0%) received red blood cells, 1863 (25.2%) received platelets, 1645 (22.2%) received plasma, and 394 (5.3%) received cryoprecipitate. Major bleeding occurred in 1773 (24.1%) patients, and major complications occurred in 740 (10.2%) patients. The trial intervention reduced rates of red blood cell transfusion (adjusted relative risk, 0.91; 95% confidence interval, 0.85-0.98; P=0.02; number needed to treat, 24.7), platelet transfusion (relative risk, 0.77; 95% confidence interval, 0.68-0.87; P<0.001; number needed to treat, 16.7), and major bleeding (relative risk, 0.83; 95% confidence interval, 0.72-0.94; P=0.004; number needed to treat, 22.6), but had no effect on other blood product transfusions or major complications.

CONCLUSIONS

Implementation of point-of-care hemostatic testing within the context of an integrated transfusion algorithm reduces red blood cell transfusions, platelet transfusions, and major bleeding following cardiac surgery. Our findings support the broader adoption of point-of-care hemostatic testing into clinical practice.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02200419.

Active Bleeding after Cardiac Surgery: A Prospective Observational Multicenter Study

MAIN OBJECTIVES

To estimate the incidence of active bleeding after cardiac surgery (AB) based on a definition directly related on blood flow from chest drainage; to describe the AB characteristics and its management; to identify factors of postoperative complications.

METHODS

AB was defined as a blood loss > 1.5 ml/kg/h for 6 consecutive hours within the first 24 hours or in case of reoperation for hemostasis during the first 12 postoperative hours. The definition was applied in a prospective longitudinal observational study involving 29 French centers; all adult patients undergoing cardiac surgery with cardiopulmonary bypass were included over a 3-month period. Perioperative data (including blood product administration) were collected. To study possible variation in clinical practice among centers, patients were classified into two groups according to the AB incidence of the center compared to the overall incidence: "Low incidence" if incidence is lower and "High incidence" if incidence is equal or greater than overall incidence. Logistic regression analysis was used to identify risk factors of postoperative complications.

RESULTS

Among 4,904 patients, 129 experienced AB (2.6%), among them 52 reoperation. Postoperative bleeding loss was 1,000 [820;1,375] ml and 1,680 [1,280;2,300] ml at 6 and 24 hours respectively. Incidence of AB varied between centers (0 to 16%) but was independent of in-centre cardiac surgical experience. Comparisons between groups according to AB incidence showed differences in postoperative management. Body surface area, preoperative creatinine, emergency surgery, postoperative acidosis and red blood cell transfusion were risk factors of postoperative complication.

CONCLUSIONS

A blood loss > 1.5 ml/kg/h for 6 consecutive hours within the first 24 hours or early reoperation for hemostasis seems a relevant definition of AB. This definition, independent of transfusion, adjusted to body weight, may assess real time bleeding occurring early after surgery.

Low Rates of Blood Transfusion in Elective Resections of Neurofibromas in a Cohort Study: Neurofibroma Length as a Predictor of Transfusion Requirement

BACKGROUND

Neurofibromas in neurofibromatosis type 1 induce aesthetic and functional morbidity. Perioperative bleeding has been reported as an obstacle to neurofibroma resections. The authors studied the requirement for blood transfusion during surgical treatment of neurofibromatosis type 1.

METHODS

Six hundred twenty-two procedures performed on 390 neurofibromatosis type 1 patients at the national referral center from 1995 to 2011 were analyzed in two chronologic sets of patients: set 1 (February of 1995 to September of 2007), in which only one surgeon operated; and set 2 (October of 2007 to January of 2011), in which two additional surgeons were involved. Malignant peripheral nerve sheath tumors, reconstructive procedures, and spontaneous hemorrhages were excluded from the analysis. Age, sex, preoperative hemoglobin concentration, location, length, estimated volume and histologic features of the largest neurofibroma (cumulative values for multiple neurofibromas), and procedure duration were studied as potential predictors of blood transfusion that were measured in terms of units of packed red blood cells.

RESULTS

Seventy reconstructive procedures, two cases of spontaneous hemorrhage, and 32 malignant peripheral nerve sheath tumor resections were excluded. Among 516 procedures (318 and 198 in sets 1 and 2, respectively), 17 (2.7 percent) required blood transfusions. The requirement for transfusion was associated with neurofibroma length in both sets, with an optimal cutoff value of 13 cm in both sets.

CONCLUSIONS

Contrary to the literature, the requirement for blood transfusion was found to be low (2.7 percent of the cases) during elective resection of neurofibromas in neurofibromatosis type 1. Elective resections of benign neurofibromas less than 13 cm in length were not associated with a requirement for blood transfusion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Impact of aspirin use on morbidity and mortality in massively transfused cardiac surgery patients: a propensity score matched cohort study

PURPOSE

Aspirin may prevent organ dysfunction in critically ill patients and mitigate transfusion associated acute lung injury. We hypothesized that aspirin use might be associated with decreased morbidity and mortality in massively transfused cardiac surgery patients.

METHODS

A single center retrospective cohort study was performed using data from an 8.5-year period (2006-2014). Massive transfusion was defined as receiving at least 2400 ml (8 units) of red blood cell units intraoperatively. A propensity score model was created to account for the likelihood of receiving aspirin and matched pairs were identified using global optimal matching. The primary endpoint, in-hospital mortality, was compared between aspirin users and non-users. Secondary outcomes including: ICU hours, mechanical lung ventilation hours, prolonged mechanical lung ventilation (>24 h), pneumonia, stroke, acute renal failure, atrial fibrillation, deep sternal wound infection, and multiple organ dysfunction syndrome were also compared.

RESULTS

Of 7492 cardiac surgery patients, 452 (6 %) were massively transfused and mortality was 30.6 %. There were 346 patients included in the matched cohort. No significant association was found between preoperative aspirin use and in-hospital mortality; absolute risk reduction with aspirin = 7.5 % (95 % CI -2.0 to 16.9 %, p = 0.12). Preoperative aspirin use was associated with fewer total mechanical lung ventilation hours (p = 0.02) and less prolonged mechanical lung ventilation; absolute risk reduction = 11.0 % (95 % CI 1.1-20.5 %, p = 0.02).

CONCLUSIONS

Preoperative aspirin use is not associated with decreased in-hospital mortality in massively transfused cardiac surgery patients, but may be associated with less mechanical lung ventilation time.

Evaluation of a novel transfusion algorithm employing point-of-care coagulation assays in cardiac surgery: a retrospective cohort study with interrupted time-series analysis

BACKGROUND

Cardiac surgery requiring the use of cardiopulmonary bypass is frequently complicated by coagulopathic bleeding that, largely due to the shortcomings of conventional coagulation tests, is difficult to manage. This study evaluated a novel transfusion algorithm that uses point-of-care coagulation testing.

METHODS

Consecutive patients who underwent cardiac surgery with bypass at one hospital before (January 1, 2012 to January 6, 2013) and after (January 7, 2013 to December 13, 2013) institution of an algorithm that used the results of point-of-care testing (ROTEM; Tem International GmBH, Munich, Germany; Plateletworks; Helena Laboratories, Beaumont, TX) during bypass to guide management of coagulopathy were included. Pre- and postalgorithm outcomes were compared using interrupted time-series analysis to control for secular time trends and other confounders.

RESULTS

Pre- and postalgorithm groups included 1,311 and 1,170 patients, respectively. Transfusion rates for all blood products (except for cryoprecipitate, which did not change) were decreased after algorithm institution. After controlling for secular pre- and postalgorithm time trends and potential confounders, the posttransfusion odds ratios (95% CIs) for erythrocytes, platelets, and plasma were 0.50 (0.32 to 0.77), 0.22 (0.13 to 0.37), and 0.20 (0.12 to 0.34), respectively. There were no indications that the algorithm worsened any of the measured processes of care or outcomes.

CONCLUSIONS

Institution of a transfusion algorithm based on point-of-care testing was associated with reduced transfusions. This suggests that the algorithm could improve the management of the many patients who develop coagulopathic bleeding after cardiac surgery. The generalizability of the findings needs to be confirmed.