Body Size, Gender, and Transfusions as Determinants of Outcome After Coronary Operations

Can machine learning provide preoperative predictions of biological hemostasis after extracorporeal circulation for cardiac surgery?

OBJECTIVES

The goal of this study was to improve decision making regarding the transfusion of patients at the end of extracorporeal circulation for cardiac surgery through machine learning predictions of the evolution of platelets counts, prothrombin ratio, and fibrinogen assay.

METHODS

Prospective data with information about patient preoperative biology and surgery characteristics were collected at Institut Mutualiste Montsouris Hospital (Paris, France) for 10 months (n = 598). For each outcome of interest, instead of arbitrarily choosing 1 machine learning algorithm, we trained and tested a variety of algorithms together with the super learning algorithm, a state-of-the-art ensemble method that aggregates all the predictions and selects the best performing algorithm (total, 137 algorithms). We considered the top-performing algorithms and compared them to more standard and interpretable multivariable linear regression models. All algorithms were evaluated through their root mean squared error, a measure of the average difference between true and predicted values.

RESULTS

The root mean squared error of the top algorithms for predicting the difference between pre- and postoperative platelet counts, prothrombin ratio, and fibrinogen assay were 38.27 × 10e9/L, 8.66%, and 0.44 g/L, respectively. The linear models had similar performances.

CONCLUSIONS

Our machine learning algorithms accurately predicted prothrombin ratio and fibrinogen assay and less accurately platelet counts. As such, our models could provide an aid-decision tool for anesthetists in an operating room; future clinical trials addressing this hypothesis are warranted.

Methadone in combination with magnesium, ketamine, lidocaine, and dexmedetomidine improves postoperative outcomes after coronary artery bypass grafting: an observational multicentre study

BACKGROUND

An optimal pharmacological strategy for fast-track cardiac anesthesia (FTCA) is unclear. This study evaluated the effectiveness and safety of an FTCA program using methadone and non-opioid adjuvant infusions (magnesium, ketamine, lidocaine, and dexmedetomidine) in patients undergoing coronary artery bypass grafting.

METHODS

This retrospective, multicenter observational study was conducted across private and public teaching sectors. We studied patients managed by a fast-track protocol or via usual care according to clinician preference. The primary outcome was the total mechanical ventilation time in hours adjusted for hospital, body mass index, category of surgical urgency, cardiopulmonary bypass time and EuroSCORE II. Secondary outcomes included successful extubation within four postoperative hours, postoperative pain scores, postoperative opioid requirements, and the development of postoperative complications.

RESULTS

We included 87 patients in the fast-track group and 88 patients in the usual care group. Fast-track patients had a 35% reduction in total ventilation hours compared with usual care patients (p = 0.007). Thirty-five (40.2%) fast-track patients were extubated within four hours compared to 10 (11.4%) usual-care patients (odds ratio: 5.2 [95% CI: 2.39-11.08; p < 0.001]). Over 24 h, fast-track patients had less severe pain (p < 0.001) and required less intravenous morphine equivalent (22.00 mg [15.75:32.50] vs. 38.75 mg [20.50:81.75]; p < 0.001). There were no significant differences observed in postoperative complications or length of hospital stay between the groups.

CONCLUSION

Implementing an FTCA protocol using methadone, dexmedetomidine, magnesium, ketamine, lignocaine, and remifentanil together with protocolized weaning from a mechanical ventilation protocol is associated with significantly reduced time to tracheal extubation, improved postoperative analgesia, and reduced opioid use without any adverse safety events. A prospective randomized trial is warranted to further investigate the combined effects of these medications in reducing complications and length of stay in FTCA.

TRIALS REGISTRATION

The study protocol was registered in the Australian New Zealand Clinical Trials Registry ( https://www.anzctr.org.au/ACTRN12623000060640.aspx , retrospectively registered on 17/01/2023).

Impact of gender differences on hemostasis in patients after coronary artery bypass grafts surgeries in the context of tranexamic acid administration

BACKGROUND

Sex differences present in the blood management of patients after coronary artery bypass grafts (CABG) surgeries. Tranexamic acid (TXA) performed well in maintaining hemostasis during and after surgeries. However, the impact of sex differences on blood control after CABG in patients who received TXA was not investigated.

METHODS

Overall, 29,536 patients undergoing CABG with TXA administration from 2009 to 2019 in our hospital were included. Propensity score matching was performed. Finally, 6808 males and 6808 females were matched based on 23 covariates.

RESULTS

Female patients had a 0.36-fold lower incidence of reoperations due to major hemorrhage or cardiac tamponade compared to males (1.3% vs. 2.0%, p = 0.001, OR = 0.64, 95%CI = 0.49-0.84). Females had a median of 100 ml less blood loss in 24 h (median 360 vs. 460 ml, p < 0.0001), 150 ml less in 48 h (median 580 vs. 730 ml, p < 0.0001), and 180 ml less in total (median 760 vs. 940 ml, p < 0.0001) than male patients. The red blood cell (RBC) transfusion rate in female was 1.53-fold higher than that in male (33.0% vs. 21.6%, OR = 1.53, 95% CI = 1.43-1.63, p < 0.0001). Females also had higher morbidities than males after CABGs.

CONCLUSIONS

Females had less blood loss than males after CABG with the TXA treatment. Females still had a higher RBC transfusion rate after surgery. Morbidities in women were also higher than that in men.

Relative impact of red blood cell transfusion and anaemia on 5-year mortality in cardiac surgery

OBJECTIVES

The aim was to compare the relative effects of red blood cell (RBC) transfusion and preoperative anaemia on 5-year mortality following open-heart cardiac surgery using structural equation modelling. We hypothesized that patient risk factors associated with RBC transfusion are of larger importance than transfusion itself.

METHODS

This prospective cohort study, part of the Cardiac Surgery Outcome Study at St. Olavs University Hospital, Trondheim, Norway, included open-heart on-pump cardiac surgery patients operated on from 2000 through 2017 (n = 9315). Structural equation modelling, which allows for intervariable correlations, was used to analyse pathway diagrams between known risk factors and observed mortality between 30 days and 5 years postoperatively. Observation times between 30 days and 1 year, and 1-5 years postoperatively were also compared with the main analysis.

RESULTS

In a simplified model, preoperative anaemia had a larger effect on 5-year mortality than RBC transfusion (standardized coefficients: 0.17 vs 0.09). The complete model including multiple risk factors showed that patient risk factors such as age (0.15), anaemia (0.10), pulmonary disease (0.11) and higher creatinine level (0.12) had larger effects than transfusion (0.03). Results from several sensitivity analyses supported the main findings. The models showed good fit.

CONCLUSIONS

Preoperative anaemia had a larger impact on 5-year mortality than RBC transfusion. Differences in 5-year mortality were mainly associated with patient risk factors.

Sex-Specific Associations Between Preoperative Anemia and Postoperative Clinical Outcomes in Patients Undergoing Cardiac Surgery

BACKGROUND

Preoperative anemia is common in cardiac surgery, yet there were limited data describing the role of sex in the associations between anemia and clinical outcomes. Understanding these relationships may guide preoperative optimization efforts.

METHODS

This is an observational cohort study of adults undergoing isolated coronary artery bypass grafting or single- or double-valve surgery from 2008 to 2018 at a large tertiary medical center. Multivariable regression assessed the associations between preoperative hemoglobin concentrations and a primary outcome of postoperative acute kidney injury (AKI) and secondary outcomes of perioperative red blood cell (RBC) transfusion, reoperation, vascular complications (ie, stroke, pulmonary embolism, and myocardial infarction), and hospital length of stay (LOS). Each outcome was a single regression model, using interaction terms to assess sex-specific associations between hemoglobin and outcome.

RESULTS

A total of 4117 patients were included (57% men). Linear splines with sex-specific knots (13 g/dL in women and 14 g/dL in men) provided the best overall fit for preoperative hemoglobin and outcome relationships. In women, each 1 g/dL decrease in hemoglobin <13 g/dL was associated with increased odds of AKI (odds ratio = 1.49; 95% confidence interval [CI], [1.23-1.81]; P < .001), and there was no significant association between hemoglobin per 1 g/dL >13 g/dL and AKI (0.90 [0.56-1.45]; P = .67). The association between hemoglobin and AKI in men did not meet statistical significance (1.10 [0.99-1.22]; P = .076, per 1 g/dL decrease <14 g/dL; 1.00 [0.79-1.26]; P = .98 for hemoglobin per 1 g/dL >14 g/dL). In women, lower preoperative hemoglobin (per 1 g/dL decrease <13 g/dL) was associated with increased odds of RBC transfusion (2.90 [2.33-3.60]; P < .001), reoperation (1.27 [1.11-1.45]; P < .001) and a longer hospital LOS (multiplicative increase in geometric mean 1.05 [1.03-1.07]; P < .001). In men, preoperative hemoglobin (per 1 g/dL decrease <14 g/dL) was associated with increased odds of perioperative RBCs (2.56 [2.27-2.88]; P < .001) and longer hospital LOS (multiplicative increase in geometric mean 1.02 [1.01-1.04] days; P < .001) but not reoperation (0.94 [0.85-1.04]; P = .256). Preoperative hemoglobin per 1 g/dL >13 g/dL in women and 14 g/dL in men were associated with lower odds of RBCs transfusion (0.57 [0.47-0.69]; P < .001 and 0.74 [0.60-0.91]; P = .005, respectively).

CONCLUSIONS

Preoperative anemia was associated with inferior clinical outcomes after cardiac surgery. The associations between hemoglobin and outcomes were distinct for women and men, with different spline knot points identified (13 and 14 g/dL, respectively). Clinicians should consider data-driven approaches to determine preoperative hemoglobin values associated with increasing risk for adverse perioperative outcomes across sexes.

Gender difference in long- and short-term outcomes of off-pump coronary endarterectomy

Background

The role of gender in the selection of the most effective method for treatment of patients with diffused coronary artery diseases remains a matter of debate. This study thus evaluated the effect of gender on long- and short-term outcomes of off-pump coronary endarterectomy (CE).

Methods

This was a single-center retrospective study of patients who had undergone coronary artery bypass graft (CABG). The patients were divided into two groups, the CABG and the CABG + CE group, and further stratified into male and female. Long-term survival for each group was estimated by Kaplan-Meier analysis with log-rank testing. In addition, Cox regression analyses of each gender were also carried out to identify the predictors of the primary and secondary endpoints.

Results

Overall, 25.8% of the patients were female. Diseased vessels were not statistically different in the two groups - men and women. There was no significant difference in postoperative outcomes between males and females in the CABG and CABG + CE groups. There was no significant difference in hospital mortality in the two groups between males and females. Kaplan-Meier curves show that there was no significant difference in the 5-year cardiac mortality between males and females belonging to the CABG and CABG + CE groups.

Conclusion

The results of this study show that there was no significant difference in the short- and long-term outcomes of off-pump CABG and CE in both genders although women tend to carry a greater risk.

Allogeneic red blood cell transfusion is an independent risk factor for 1-year mortality in elderly patients undergoing femoral neck fracture surgery: Retrospective study

Allogeneic red blood cell transfusion (ABT) is 1 of the poor prognostic factors for morbidity and mortality in patients with hip fracture, particularly among elderly patients. This study aimed to investigate the risk factors for ABT and 1-year mortality in elderly patients undergoing surgery for femoral neck fracture.A total of 225 elderly patients who underwent femoral neck fracture surgery between May 2013 and November 2015 at a tertiary medical center were retrospectively recruited. Medical records were analyzed.The median patient age was 80 years and 28.4% were men. A total of 113 patients received ABT (50.2%). Multivariate logistic regression analysis showed that female sex (odds ratio [OR] 2.606, 95% confidence interval [CI] 1.283-5.295, P = .008), malignancy (OR 5.098, 95% CI 1.725-15.061, P = .003), chronic kidney disease stage ≥ 3 (OR 3.258, 95% CI 1.603-6.622, P = .001), and anemia (hemoglobin < 12 g/dL) (OR 4.684, 95% CI 2.230-9.837, P < .001) were significantly associated with ABT. The 1-year mortality rate after surgery was 15.1%. Male sex (OR 2.477, 95% CI 1.101-5.575, P = .028), ABT (OR 2.367, 95% CI 1.036-5.410, P = .041), and intensive care unit admission (OR 5.564, 95% CI 1.457-21.249, P = .012) were significantly associated with 1-year mortality.In this study, underlying comorbidities such as chronic kidney disease and malignancy were associated with ABT. Furthermore, ABT was a significant independent risk factor for 1-year mortality. These findings suggest that underlying comorbidities and the need for ABT should be considered in the risk assessment of elderly patients with femoral neck fracture to improve the outcomes after surgery.

Net Prime Volume Is Associated with Increased Odds of Blood Transfusion

Hemodilutional anemia has been cited as a contributing factor to red blood cell (RBC) transfusions in cardiac surgery patients. Accordingly, efforts have been made to minimize hemodilution by reducing cardiopulmonary bypass (CPB) prime volume. We sought to assess the impact of these efforts on intraoperative RBC transfusions. We evaluated 21,360 patients undergoing coronary artery bypass with or without aortic valve surgery between July 2011 through December 2016 at any of 42 centers participating in the Perfusion Measures and Outcomes registry. The primary exposure was net CPB prime volume (total prime volume minus retrograde autologous prime volume) indexed to body surface area (mL/m²), which was further divided into quartiles (Q1: <262 mL/m², Q2: 262-377 mL/m², Q3: 377-516 mL/m², and Q4: >516 mL/m²). The primary outcome was intraoperative RBC transfusion. We modeled the effect of index net prime volume on transfusion, adjusting for patient (age, gender, race, diabetes, vascular disease, previous myocardial infarction, ejection fraction, creatinine, preoperative hematocrit (HCT), total albumin, status, aspirin, and antiplatelet agents), procedural (procedure types) characteristics, surgical year, and hospital. The median net prime volume was 378 mL/m² (25th percentile: 262 mL/m², 75th percentile: 516 mL/m²). Relative to patients in Q1, patients in Q4 were more likely to be older, female, nondiabetic, have higher ejection fraction, have more ultrafiltration volume removed, and undergo more elective and aortic valve procedures (all p < .05). Patients in Q4 relative to Q1 were exposed to lower nadir HCTs on bypass, p < .05. The net prime volume was associated with an increased risk of transfusion (8.9% in Q1 vs. 22.6% in Q4, p < .001). After adjustment, patients in Q4 (relative to Q1) had a 2.9-fold increased odds (OR_adj = 2.9, 95% CI [2.4, 3.4]) of intraoperative RBC transfusion. In this large, multicenter experience, patients exposed to larger net prime volumes were associated with greater adjusted odds of receiving intraoperative transfusions. Our findings reinforce the importance of efforts to reduce the net CPB prime volume. Based on these findings and other supporting evidence, the net prime volume should be adopted as a national quality measure.

Adiposity in relation to readmission and all-cause mortality following coronary artery bypass grafting: A systematic review and meta-analysis

This study systemically reviewed evidence linking adiposity to readmission and all-cause mortality in post-coronary artery bypass grafting (CABG) patients. Keyword/reference search was performed in PubMed, Web of Science, CINAHL, and Cochrane Library for articles published before June, 2018. Eligibility criteria included study designs: experimental/observational studies; subjects: adult patients undergoing CABG; and outcomes: hospital/clinic readmissions, and short-term (≤30 days) and mid-to-long-term (>30 days) all-cause mortality. Seventy-two studies were identified. Meta-analysis showed that the odds of post-CABG readmission among patients with overweight was 30% lower than their normal-weight counterparts and the odds of mid-to-long-term post-CABG mortality among patients with overweight were 20% lower than their normal-weight counterparts. In contrast, no difference in post-CABG readmission rate was found between patients with obesity and their nonobese counterparts; no difference in short-term or in-hospital post-CABG mortality rate was found between patients with overweight or obesity and their normal-weight counterparts; and no difference in mid-to-long-term post-CABG mortality rate was found between patients with obesity and their normal-weight counterparts. In conclusion, patients with overweight but not obesity had a lower readmission and mid-to-long-term mortality rate following CABG relative to their normal-weight counterparts. Preoperative weight loss may not be advised to patients with overweight undergoing CABG.

Red blood cell transfusion threshold after pediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Restrictive red blood cell transfusion strategy is implemented to minimize risk following allogeneic blood transfusion in adult cardiac surgery. However, it is still unclear if it can be applied to pediatric cardiac patients. The purpose of this systematic review and meta-analysis was to determine the effect of postoperative restrictive transfusion thresholds on clinical outcomes based on up-to-date results of randomized controlled trials (RCTs) and observational studies in pediatric cardiac surgery.

METHOD

We searched for RCTs and observational studies in the following databases: the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and ClinicalTrials.gov from their inception to October 26, 2017. We also searched reference lists of published guidelines, reviews, and relevant articles, as well as conference proceedings. No language restrictions were applied and no observational study met the inclusion criteria.

RESULTS

Four RCTs on cardiac surgery involving 454 patients were included. There were no differences in the pooled fixed effects of intensive care unit (ICU) stay between the liberal and restrictive transfusion thresholds (standardized mean difference SMD, 0.007; 95% confidence interval CI, -0.18-0.19; P = .94). There were also no differences in the length of hospital stay (SMD, -0.062; 95% CI, -0.28-0.15; P = .57), ventilation duration (SMD, -0.015; 95% CI, -0.25-0.22; P = .90), mean arterial lactate level (SMD, 0.071; 95% CI, -0.22-0.36; P = .63), and mortality (risk ratio, 0.49; 95% CI, 0.13-1.94; P = .31). There was no inter-trial heterogeneity for any pooled analysis. Publication bias was tested using Egger, Begg, or the trim-and-fill test, and the results indicated no significant publication bias.

CONCLUSION

Evidence from RCTs in pediatric cardiac surgery, though limited, showed non-inferiority of restrictive thresholds over liberal thresholds in length of ICU stay and other outcomes following red blood cell transfusion. Further high-quality RCTs are necessary to confirm the findings.

Transfusion requirements and 30-day mortality predictors for adult hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome characterized by an uncontrolled hyper-inflammatory response. We assessed the transfusion requirements and predictors of 30-day mortality for adult HLH patients. We identified all adult patients with a diagnosis of HLH at a large academic hospital from October 2003 through February 2017. We extracted patients' clinical and laboratory data, including transfusion requirements, from their medical records. One-hundred sixteen patients were identified. Their median age was 48 years (range 18-82); 72(62%) were male. Median duration of hospital stay was 19 days (range 1-89 days). At 30 days from admission, 81(70%) patients were alive. Death was attributed to sepsis in 21 patients, lymphoma in six, bleeding in four, GVHD in one, liver failure in one, metastatic solid tumor in one, and unknown in one. Transfusion requirements at 30 days from admission were as follows: RBC, 86% of patients, median 6 units (range 1-58); platelets, 74% of patients, median 6 units (1-67); plasma, 40% of patients, median 4 units (1-56). Renal failure (OR = 4.39; P = 0.008) and hypofibrinogenemia (OR = 4.07; P = 0.009) correlated with 30-day mortality. The transfusion requirements for adult HLH patients were high. Our study indicated that renal insufficiency and hypofibrinogenemia are predictors of early death in adult HLH.

Gender disparities in red blood cell transfusion in elective surgery: a post hoc multicentre cohort study

OBJECTIVES

A post hoc gender comparison of transfusion-related modifiable risk factors among patients undergoing elective surgery.

SETTINGS

23 Austrian centres randomly selected and stratified by region and level of care.

PARTICIPANTS

We consecutively enrolled in total 6530 patients (3465 women and 3065 men); 1491 underwent coronary artery bypass graft (CABG) surgery, 2570 primary unilateral total hip replacement (THR) and 2469 primary unilateral total knee replacement (TKR).

MAIN OUTCOME MEASURES

Primary outcome measures were the number of allogeneic and autologous red blood cell (RBC) units transfused (postoperative day 5 included) and differences in intraoperative and postoperative transfusion rate between men and women. Secondary outcomes included perioperative blood loss in transfused and non-transfused patients, volume of RBCs transfused, perioperative haemoglobin values and circulating red blood volume on postoperative day 5.

RESULTS

In all surgical groups, the transfusion rate was significantly higher in women than in men (CABG 81 vs 49%, THR 46 vs 24% and TKR 37 vs 23%). In transfused patients, the absolute blood loss was higher among men in all surgical categories while the relative blood loss was higher among women in the CABG group (52.8 vs 47.8%) but comparable in orthopaedic surgery. The relative RBC volume transfused was significantly higher among women in all categories (CABG 40.0 vs 22.3; TKR 25.2 vs 20.2; THR 26.4 vs 20.8%). On postoperative day 5, the relative haemoglobin values and the relative circulating RBC volume were higher in women in all surgical categories.

CONCLUSIONS

The higher transfusion rate and volume in women when compared with men in elective surgery can be explained by clinicians applying the same absolute transfusion thresholds irrespective of a patient's gender. This, together with the common use of a liberal transfusion strategy, leads to further overtransfusion in women.

Effect of small body habitus on peri-operative outcomes after robotic-assisted pulmonary lobectomy: retrospective analysis of 208 consecutive cases

BACKGROUND

Patients with smaller body surface area (BSA) have smaller pleural cavities, which limit visualization and instrument mobility during video-assisted thoracoscopic surgery (VATS). We investigated the effects of BSA on outcomes with robotic-assisted VATS lobectomy.

METHODS

We analyzed 208 consecutive patients who underwent robotic-assisted lobectomy over 34 months. Patients were separated into group A (BSA ≤1.65 m(2)) and group B (BSA >1.65 m(2)). Operative times, estimated blood loss (EBL), conversions to thoracotomy, complications, hospital length of stay (LOS), and in-hospital mortality were compared.

RESULTS

Group A had 40 patients (BSA 1.25-1.65 m(2)), and group B had 168 patients (BSA 1.66-2.86 m(2)). Median skin-to-skin operative times [± standard error of the mean (SEM)] were 169±16 min for group A and 176±6 min for group B (P=0.34). Group A had median EBL of 150±96 mL compared to 200±24 mL for group B (P=0.37). Overall conversion rate to thoracotomy was 8/40 (20.0%) in group A versus 12/168 (7.1%) in group B (P=0.03); while emergent conversion for bleeding was 2/40 (5.0%) in group A versus 5/168 (3.0%) in group B (P=0.62). Postoperative complications occurred in 12/40 (30.0%) in group A, compared to 66/168 (39.3%) in group B (P=0.28). Patients from both groups had median hospital LOS of 5 days (P=0.68) and had similar in-hospital mortality.

CONCLUSIONS

Patients with BSA ≤1.65 m(2) have similar perioperative outcomes and complication risks as patients with larger BSA. Patients with BSA ≤1.65 m(2) have a higher overall conversion rate to thoracotomy, but similar conversion rate for bleeding as patients with larger BSA. Robotic-assisted pulmonary lobectomy is feasible and safe in patients with small body habitus.

The association between body mass index and outcome after coronary artery bypass grafting operations

OBJECTIVES

This investigation was undertaken to analyse the association between body mass index (BMI) and morbidity after coronary artery bypass graft (CABG) operations.

METHODS

The setting was a cardiovascular intensive care unit (ICU) of a tertiary medical referral centre. This was a retrospective review; patients were classified according to their BMI into five groups: underweight <18.5 kg/m(2); normal weight 18.5-24.9 kg/m(2); overweight 25-29.9 kg/m(2); Class I obesity 3034.9 kg/m(2); and Class II/III obesity >35 kg/m(2). We included patients who underwent isolated CABG between January 3, 2006 and March 8, 2011. After including only the initial operation or admission in patients with more than one operation or hospital admission and excluding patients with any missing variable, 3470 patients remained in the analyses. The primary outcomes analysed were hospital mortality and pulmonary and infection morbidities. We secondarily assessed the association between BMI category and each of the three outcomes.

RESULTS

Respective mortality, and pulmonary and infection morbidity occurrence rates were: 8.7, 13.0 and 13.0% for the underweight; 2.4, 8.0 and 4.8% for the overweight; 1.8, 10.9 and 5.6% for the Class I obesity group; and 2.7, 11.1 and 5.7% for the Class II/III obesity group, vs 2.3, 7.0 and 6.2% for the normal weight group. Class I and II/III obesity patients were more likely to have pulmonary morbidity compared with the normal weight group, after adjusting for the potential confounding variables.

CONCLUSIONS

Class I and Class II/III obesity (BMI ≥30 kg/m(2)) was associated with increased pulmonary morbidity after CABG operations. There was no difference in mortality or infection morbidity in any BMI group compared with the normal group.

The future of observational research and randomized controlled trials in red blood cell transfusion medicine

Red blood cell (RBC) transfusions are commonplace in the intensive care unit (ICU) with at least 30% of ICU patients receiving a RBC transfusion at some point during their ICU stay. However, which patients should be transfused and what transfusion trigger(s) should be used remains unclear. RBC transfusion can be associated with adverse effects, but anemia is also associated with worse outcomes. Observational studies and randomized controlled trials (RCTs) have been conducted to try and answer some of the questions surrounding blood transfusion in critically ill patients. The need for blood transfusion and the benefit/risk ratio vary according to individual patient characteristics, including age and comorbidities, so large-scale RCTs in heterogeneous groups of patients may not be the most appropriate tool to investigate these issues; smaller RCTs in carefully defined patient groups may provide more useful information. Rigorous statistical analysis of large, carefully conducted observational studies will also help enhance our evidence-base in this field.

Advances in Perfusion Techniques: Minimally Invasive Procedures

There is a growing demand from patients and referring physicians for minimally invasive cardiac surgery. Minimally invasive cardiac procedures are technically unique from conventional cardiac procedures and require a thorough understanding of the surgical, anesthetic, and perfusion strategies. Strategies include routine use of augmented venous drainage, alternative arterial and venous cannulation sites, and special cannulas designed for minimally invasive procedures. The following review describes the strategies and safety systems that should be considered when performing minimally invasive cardiac surgery.

Is crystalloid cardioplegia a strong predictor of intra-operative hemodilution?

INTRODUCTION

Complications due to hemodilution (hematocrit value less than 22%) after cardiopulmonary bypass inevitably resulted with significantly greater intensive care requirements, long hospital stays, more operative costs, and increased mortality rates. We tried to identify whether crystalloid cardioplegia is the strongest predictor of intraoperative hemodilution or not.

MATERIALS AND METHODS

One hundred patients were included into this randomized prospective study. Patients were divided into the two groups. Crystalloid cardioplegia were given to the odd-numbered patients (Group 1, n=50 patients) and blood cardioplegia were given to the even-numbered patients (Group 2, n=50 patients). St. Thomas-II solution was used in Group-1 and Calafiore cold blood cardioplegia was in Group-2.

RESULTS

Average intraoperative hematocrit value was 18.4% ± 2.3 in crystalloid group 24.2% ± 3.4 in blood cardioplegia group (p<0.001). The lowest hematocrit value was 15% and 20% in two groups respectively (p<0.001). In crystalloid group average intraoperative packed red blood cell (RBC) transfusion was 2.3 ± 0.41 units, 0.7 ± 0.6 units blood cardioplegia group (p=0.001). Average transfused RBC was 2.7 ± 0.8 units in crystalloid group, 0.9 ± 0.4 units blood cardioplegia group (p<0.001). Multivariate analyses confirmed age (p = 0.005, OR = 3.78), female gender (p = 0.003, OR = 2.91), longer cross-clamp time (>60 minutes) (p = 0.001, OD = 0.97), body surface area <1.6 m2 (p = 0.001, OR = 6.01) and crystalloid cardioplegia (p < 0.001, OR = 0.19) as predictor of intraoperative hemodilution.

CONCLUSION

Crystalloid cardioplegia, compared to blood cardioplegia not only causes much more intra-operative hemodilution but also increases the blood transfusion requirement. Hemodilution and increased transfusion increases the intensive care unit and hospital stay, in the early postoperative period.

Safety and efficacy of prothrombin complex concentrates for the treatment of coagulopathy after cardiac surgery

OBJECTIVE

Coagulopathy is an important cause of bleeding after complex cardiac surgery. The conventional treatment for coagulopathy is transfusion, which is associated with adverse outcomes. We report our initial experience with the prothrombin complex concentrate FEIBA (factor VIII inhibitor bypassing activity) for the rescue treatment of coagulopathy and life-threatening bleeding after cardiac surgery.

METHODS

Twenty-five patients who underwent cardiac surgery with coagulopathy and life-threatening bleeding refractory to conventional treatment received FEIBA as rescue therapy at our institution. This cohort represents approximately 2% of patients undergoing cardiac surgery in our university-based practice during the study.

RESULTS

The patients were at high risk for postoperative coagulopathy with nearly all patients having at least 2 risk factors for this. Aortic root replacement (Bentall or valve-sparing procedure) and heart transplant with or without left ventricular assist device explant were the most common procedures. The mean FEIBA dose was 2154 units. The need for fresh frozen plasma and platelet transfusion decreased significantly after FEIBA administration (P = .0001 and P < .0001). The mean internationalized normalized ratio decreased from 1.58 to 1.13 (P < .0001). Clinical outcomes were excellent. No patient returned to the operating room for reexploration. There was no hospital mortality and all patients were discharged home. One patient who had a central line and transvenous pacemaker developed an upper extremity deep vein thrombosis.

CONCLUSIONS

Our initial experience with FEIBA administration for the rescue treatment of postoperative coagulopathy and life-threatening bleeding has been favorable. Further studies are indicated to confirm its efficacy and safety and determine specific clinical indications for its use in patients undergoing cardiac surgery.

Effect of body mass index on early clinical outcomes after cardiac surgery

Background

there are several reports on the outcomes of cardiac surgery in relation to body mass index. Some concluded that obesity did not increase morbidity or mortality after cardiac surgery, whereas others demonstrated that obesity was a predictor of both morbidity and mortality.

Methods

this was a retrospective study of 3370 adult patients undergoing cardiac surgery. The patients were divided into 4 groups according to body mass index. The 4 groups were compared in terms of preoperative, operative, and postoperative characteristics.

Results

obese patients had a significantly younger mean age. Diabetes, hypertension, and hyperlipidemia were significantly more common in obese patients. The crossclamp time was significantly longer in the underweight group. Reoperation for bleeding, and pulmonary, gastrointestinal, and renal complications were significantly more common in the underweight group. Wound complications were significantly more frequent in the obese group. Mortality was inversely proportional to body mass index. The adjusted odds ratios of the early clinical outcomes demonstrated a higher risk of wound complications in overweight and obese patients

Conclusion

body mass index has no effect on early clinical outcomes after cardiac surgery, except for a higher risk of wound complications in overweight and obese patients.

Fresh-frozen plasma transfusion did not reduce 30-day mortality in patients undergoing cardiopulmonary bypass cardiac surgery with excessive bleeding: the PLASMACARD multicenter cohort study

BACKGROUND

During on-pump cardiac surgery, hemorrhagic complications occur frequently. Fresh-frozen plasma (FFP) is widely transfused to provide coagulation factors. Yet, no randomized clinical trial has demonstrated its benefits on mortality. We assessed the relationship between therapeutic transfusion of FFP and 30-day mortality in cardiac surgery patients suffering from excessive bleeding in a prospective cohort study.

STUDY DESIGN AND METHODS

Adult patients who underwent on-pump cardiac surgery and experienced excessive bleeding during the 48-hour perioperative period were recruited from 15 French centers between February 2004 and January 2006. Patients who received a preventive FFP transfusion were excluded. The association between FFP transfusion and all cause 30-day mortality was estimated using a Cox proportional hazards model, adjusted for confounding. A propensity score (PS) sensitivity analysis was also performed.

RESULTS

Among 967 patients included in this study, 58.1% received FFP. The median dose was 11.3 mL/kg (interquartile range, 7.6-19.5). The cumulative 30-day mortality rate was 11.3% (95% confidence interval [CI], 9.5-13.5). FFP transfusion was associated with a higher 30-day mortality (hazard ratio [HR], 3.2; 95% CI, 1.7-6.1) in univariate analysis; however, after adjusting for prognostic factors, there was no longer any association (HR, 1.5; 95% CI, 0.8-3.0, p = 0.20). The results of the PS analysis were consistent with the adjusted analysis.

CONCLUSION

Among on-pump cardiac surgery patients experiencing excessive perioperative bleeding, there is no evidence of a beneficial impact of FFP transfusion on mortality.

An obesity paradox of Asian body mass index after cardiac surgery: arterial oxygenations in duration of mechanic ventilation

BACKGROUND

Numerous studies have documented an obesity paradox that overweight of Caucasian patients has better prognosis after cardiac surgery. This study is to examine Asian patients' BMI to see whether an obesity paradox exists in DMV after cardiac surgery.

METHODS

A retrospective study consisted of 428 patients after cardiac surgery from January 2006 to December 2010 in the medical center of Taiwan. The Asian BMI was divided into 3 groups: under-normal weight patients (BMI < 24; n = 165), overweight patients (BMI 24 to <27; n = 130), and obese patients (BMI ≥ 27; n = 133). Multivariable analysis and paired t were used to compare all variables.

RESULTS

Overweight patients were significantly associated with the shortest DMV. Under-normal weight patients had significantly better oxygenations of AaDO₂ and P/F ratio in the DMV; however, they correlated with the longest DMV, older age, more female, lower LVSV, higher BUN, more dialysis-dependent, and poorer outcomes, namely, 1-year mortality, HAP, reintubation, tracheotomy, and LOS.

CONCLUSIONS

Asian overweight patients after cardiac surgery have better prognosis. Under-normal weight patients have higher risk factors, longer DMV, and poorer outcomes; even though they have better arterial oxygenations, they seem to need better arterial oxygenations for successful weaning ventilator.

Risks associated with the transfusion of various blood products in aortic valve replacement

BACKGROUND

Patients undergoing cardiac operations often require transfusions of red blood cells, plasma, and platelets. From a statistical point of view, there is a significant collinearity between the components, but they differ in indications for use and composition. This study explores the relationship between the transfusion of different blood components and long-term mortality in patients undergoing aortic valve replacement alone or combined with revascularization.

METHODS

A retrospective single-center study was performed including 1,311 patients undergoing aortic valve replacement. Patients who received more than 7 units of red blood cells, those who died early (7 days), and emergency cases were excluded. Patients were monitored for up to 9.5 years. A broad selection of potential risk factors were analyzed using Cox proportional hazards regression, where transfusion of red blood cells, plasma, and platelets were forced to remain in the model.

RESULTS

The transfusion of red blood cells was not associated with decreased long-term survival (hazard ratio [HR], 1.01; p = 0.520) nor was the transfusion of platelets (HR, 0.946; p = 0.124); however, the transfusion of plasma was (HR, 1.041; p < 0.001). All HRs are per unit of blood product transfused. No increased risk was found for patients undergoing a combined procedure.

CONCLUSIONS

No significant risk for long-term mortality was associated with transfusion of red blood cells during the study period. However, the transfusion of plasma was associated with increased mortality.

Increased long-term mortality with plasma transfusion after coronary artery bypass surgery

PURPOSE

Patients undergoing cardiac surgery often require transfusions of red blood cells, plasma and platelets. These components differ widely in both indications for use and composition. However, from a statistical point of view there is a significant colinearity between the components. This study explores the relation between the transfusion of different blood components and long-term mortality.

METHODS

A retrospective single-centre study was performed including 5,261 coronary artery bypass grafting patients, excluding patients receiving more than eight units of red blood cells, those suffering early death (7 days) and emergency cases. Patients were followed up for a period of up to 7.5 years. A broad spectrum of potential risk factors was analysed using Cox proportional hazards survival regression. Non-significant risk factors were removed by step-wise elimination, and transfusion of red blood cells, plasma and platelets was forced to remain in the model.

RESULTS

The transfusion of red blood cells was not associated with decreased long-term mortality (HR = 1.007, p = 0.775), whereas the transfusion of plasma was associated with decreased long-term survival (HR = 1.060, p < 0.001), and the transfusion of platelets was associated with increased long-term survival (HR = 0.817, p = 0.011). The risk associated with transfusion of plasma was mainly attributed to patients receiving large amounts of plasma. All hazard ratios are per unit of blood product transfused.

CONCLUSIONS

No association was found between the transfusion of red blood cells and mortality during the study period. However, transfusion of plasma was associated with increased mortality while transfusion of platelets was associated with decreased mortality during the study period.

"Polarizing" microplegia improves cardiac cycle efficiency after CABG for unstable angina

BACKGROUND

Myocardial protection during coronary artery bypass grafting (CABG) for unstable angina (UA) still represents a major challenge, ought to the risk for further ischemia/reperfusion injury. Few studies investigate the biochemical, hemodynamic and echocardiographic results of microplegia (Mic) in UA.

METHODS

Eighty UA-patients undergoing CABG were randomized to Mic (Mic-Group) or standard 4:1 blood Buckberg-cardioplegia (Buck-Group). Troponin-I and lactate were sampled from coronary sinus at reperfusion (T1), and from peripheral blood preoperatively (T0), at 6 (T2), 12 (T3) and 48 (T4) hours. Cardiac index (CI), indexed systemic vascular resistances (ISVR), Δp/Δt, cardiac cycle efficiency (CCE), and central venous pressure (CVP) were collected preoperatively (T0), and since Intensive Care Unit (ICU)-arrival (T1) to 24h (T5). Echocardiographic E-wave (E), A-wave (A), E/A, peak early-diastolic TDI-mitral annular-velocity (Ea), and E/Ea investigated the diastolic function and Wall Motion Score Index (WMSI) the systolic function, preoperatively (T0) and at 96h (T1).

RESULTS

Mic-Group showed lower troponin-I and lactate from coronary sinus (p=.0001 for both) and during the postoperative course (between-groups p=.001 and .0001, respectively). WMSI improved only after Mic (time-p=.001). Higher CI Δp/Δt and CCE (between-groups p=.0001), with comparable CVP and ISVR (p=N.S.) were detected after Mic. Diastolic function improved in both groups, but better after Mic (between-groups p=.003, .001, and .013 for E, E/A, and Ea, respectively). Mic resulted in lower transfusions (p=.006) and hospitalization (p=.002), and a trend towards lower need/duration of inotropes (p=.04 and p=.041, respectively), and ICU-stay (p=.015).

CONCLUSION

Microplegia attenuates myocardial damage in UA, reduces transfusions, improves postoperative systo-diastolic function, and shortens hospitalization.

Clinical effectiveness of fresh frozen plasma compared with fibrinogen concentrate: a systematic review

Introduction

Haemostatic therapy in surgical and/or massive trauma patients typically involves transfusion of fresh frozen plasma (FFP). Purified human fibrinogen concentrate may offer an alternative to FFP in some instances. In this systematic review, we investigated the current evidence for the use of FFP and fibrinogen concentrate in the perioperative or massive trauma setting.

Methods

Studies reporting the outcome (blood loss, transfusion requirement, length of stay, survival and plasma fibrinogen level) of FFP or fibrinogen concentrate administration to patients in a perioperative or massive trauma setting were identified in electronic databases (1995 to 2010). Studies were included regardless of type, patient age, sample size or duration of patient follow-up. Studies of patients with congenital clotting factor deficiencies or other haematological disorders were excluded. Studies were assessed for eligibility, and data were extracted and tabulated.

Results

Ninety-one eligible studies (70 FFP and 21 fibrinogen concentrate) reported outcomes of interest. Few were high-quality prospective studies. Evidence for the efficacy of FFP was inconsistent across all assessed outcomes. Overall, FFP showed a positive effect for 28% of outcomes and a negative effect for 22% of outcomes. There was limited evidence that FFP reduced mortality: 50% of outcomes associated FFP with reduced mortality (typically trauma and/or massive bleeding), and 20% were associated with increased mortality (typically surgical and/or nonmassive bleeding). Five studies reported the outcome of fibrinogen concentrate versus a comparator. The evidence was consistently positive (70% of all outcomes), with no negative effects reported (0% of all outcomes). Fibrinogen concentrate was compared directly with FFP in three high-quality studies and was found to be superior for > 50% of outcomes in terms of reducing blood loss, allogeneic transfusion requirements, length of intensive care unit and hospital stay and increasing plasma fibrinogen levels. We found no fibrinogen concentrate comparator studies in patients with haemorrhage due to massive trauma, although efficacy across all assessed outcomes was reported in a number of noncomparator trauma studies.

Conclusions

The weight of evidence does not appear to support the clinical effectiveness of FFP for surgical and/or massive trauma patients and suggests it can be detrimental. Perioperatively, fibrinogen concentrate was generally associated with improved outcome measures, although more high-quality, prospective studies are required before any definitive conclusions can be drawn.

Association between body mass index and outcome of coronary artery bypass

Studies have shown disparate findings regarding body mass index and outcomes after coronary artery bypass. We analyzed body mass index and other clinical variables that might predict morbidity and mortality after primary isolated coronary artery bypass. Data on 4,425 patients (79% men) were reviewed retrospectively. They were classified as underweight (1.6%), normal weight (65%), obese (32%), and morbidly obese (1.4%) according to body mass index < 20, 20–29, 30–39, and > 40 kgċm−2, respectively. Multiple logistic regression was used for correlates of 30-day outcome. Cox regression was used for predictors of late outcome in underweight and morbidly obese patients. There were 45 (1%) deaths and 234 (5%) cases of morbidity within 30 days. Independent correlates of 30-day morbidity were smoking, logistic EuroSCORE, blood and blood product transfusions. Correlates of 30-day mortality were logistic EuroSCORE and blood transfusion. The only independent predictor of late death in underweight and morbidly obese patients was preoperative arrhythmia. Body mass index was not a predictor of 30-day morbidity or mortality. The 1-, 3-, and 7-year survival rates were not significantly different between underweight and morbidly obese patients. Body mass index did not affect short-term outcomes after primary coronary artery bypass grafting.

The effect of diabetes on mortality in critically ill patients: a systematic review and meta-analysis

Introduction

Critically ill patients with diabetes are at increased risk for the development of complications, but the impact of diabetes on mortality is unclear. We conducted a systematic review and meta-analysis to determine the effect of diabetes on mortality in critically ill patients, making a distinction between different ICU types.

Methods

We performed an electronic search of MEDLINE and Embase for studies published from May 2005 to May 2010 that reported the mortality of adult ICU patients. Two reviewers independently screened the resultant 3,220 publications for information regarding ICU, in-hospital or 30-day mortality of patients with or without diabetes. The number of deaths among patients with or without diabetes and/or mortality risk associated with diabetes was extracted. When only crude survival data were provided, odds ratios (ORs) and standard errors were calculated. Data were synthesized using inverse variance with ORs as the effect measure. A random effects model was used because of anticipated heterogeneity.

Results

We included 141 studies comprising 12,489,574 patients, including 2,705,624 deaths (21.7%). Of these patients, at least 2,327,178 (18.6%) had diabetes. Overall, no association between the presence of diabetes and mortality risk was found. Analysis by ICU type revealed a significant disadvantage for patients with diabetes for all mortality definitions when admitted to the surgical ICU (ICU mortality: OR [95% confidence interval] 1.48 [1.04 to 2.11]; in-hospital mortality: 1.59 [1.28 to 1.97]; 30-day mortality: 1.62 [1.13 to 2.34]). In medical and mixed ICUs, no effect of diabetes on all outcomes was found. Sensitivity analysis showed that the disadvantage in the diabetic surgical population was attributable to cardiac surgery patients (1.77 [1.45 to 2.16], P < 0.00001) and not to general surgery patients (1.21 [0.96 to 1.53], P = 0.11).

Conclusions

Our meta-analysis shows that diabetes is not associated with increased mortality risk in any ICU population except cardiac surgery patients.

Postoperative complications associated with transfusion of platelets and plasma in cardiac surgery

BACKGROUND

Studies in cardiac surgery have reported increased postoperative morbidity and mortality after allogeneic red blood cell (RBC) transfusions. Whether platelet (PLT) and/or plasma transfusions are a marker for more concomitant RBC transfusions or are independently associated with complications after cardiac surgery is unknown.

STUDY DESIGN AND METHODS

Data from two randomized controlled studies were combined to analyze the effects of PLT and/or plasma transfusions on postoperative infections, length of stay in the intensive care unit (ICU), all-cause mortality, and mortality in the presence or absence of infections in the postoperative period.

RESULTS

After adjusting for confounding factors, plasma units and not RBC transfusions were associated with all-cause mortality. White blood cell (WBC)-containing RBC transfusions and PLT transfusions were associated with mortality occurring in the presence of or after infections. The number of (WBC-containing) RBC transfusions was also significantly associated with postoperative infections and with ICU stay for 4 or more days.

CONCLUSION

Although it is difficult to separate the effects of blood components, we found that in cardiac surgery, perioperative plasma transfusions are independently associated with all-cause mortality. WBC-containing RBC transfusions and PLT transfusions are independently associated with mortality in the presence of infections in the postoperative period. Future transfusion studies in cardiac surgery should concomitantly consider the possible adverse effects of all the various transfused blood components.

Relative survival after CABG surgery is poorer in women and in patients younger than 70 years at surgery

OBJECTIVE

The difference in survival between genders after coronary artery bypass surgery (CABG) have been studied with varying results. We wanted to investigate gender and age specific relative survival in the CABG population. Risk factors increasing hazard of death in female patients were isolated.

DESIGN

Retrospectively, 6699 primary isolated CABG procedures were investigated. Long-term survival compared to expected survival in the background population was described through Kaplan-Meier plots. Two subgroups of female patients were described through baseline characteristics, t-tests, odds ratio and multivariate analysis to investigate risk factors for death within one year after surgery.

RESULTS

Women had significantly decreased relative long-term survival compared to men in this study. Relative survival was lower in patients below 70 years of age at surgery with about the same gender difference. Low ejection fraction, left main stem stenosis and reduced renal function were found to increase risk of death within one year after CABG in women, while body size quantified by body surface area (BSA) did not.

CONCLUSION

Relative long-term survival after CABG was poorer in female compared to male patients. This tendency was kept or strengthened when only those less than 70 years of age at surgery were investigated. Lower female survival was most likely due to more comorbidity in female patients. Relative survival was lower in patients <70 years.

Strategies and outcomes of cardiac surgery in Jehovah's Witnesses

BACKGROUND

Jehovah's Witnesses (JW) are a Christian faith, with an estimated 1.1 million members in the United States, well recognized for their refusal of blood and blood products. JW may not be considered for cardiac surgery due to perceived higher risks of morbidity and mortality. This study reviews our contemporary strategies and experience with JW undergoing routine and complex cardiac surgery.

METHODS

From November 2001 to April 2010, 40 JW were referred for cardiac surgery at a single quaternary referral institution. A retrospective analysis of demographic data, perioperative management, and clinical outcomes was examined. Published validated clinical risk calculator and model for prediction of transfusion were used to identify high-risk patients (risk of mortality >6% or probability of transfusion >0.80).

RESULTS

The mean age was 70 (± 9.5) years with 21 men and 19 women. Patients were classified as high risk (45%, n = 18) and low risk (55%, n = 22) with demographics and comorbidities listed in Table 2. Operative procedures included: isolated coronary artery bypass grafting (CABG) (n = 19), isolated valve replacement/repair (n = 7), valve/CABG (n = 7), reoperative valve replacement (n = 4), reoperative CABG (n = 2), valve/ascending aorta replacement (n = 1), and CABG/ascending aorta replacement (n = 1). All JW were evaluated by The Department of Bloodless Medicine to individually define acceptable blood management strategies. The mean preoperative hemoglobin was 14.1 g/dL (±1.6). Overall mortality was 5% (n = 2) all of which were in the high-risk group.

DISCUSSION

Using a multidisciplinary approach to blood management, JW can safely undergo routine and complex cardiac surgery with minimal morbidity and mortality.

Effects of sex, body mass index, and body size on the outcome of coronary artery bypass surgery: Iranian experience

OBJECTIVE

Sex, body mass index, and body surface area have been proposed as important determinants of outcome after coronary artery bypass graft surgery.

METHODS

In a retrospective study, the archived files of the patients who had undergone isolated coronary artery bypass graft (CABG) in our center from January 2005 to September 2008 were evaluated. The data regarding the patients' body surface area (BSA), body mass index (BMI), and laboratory tests as well as their demographic data and the number of deaths, duration of intensive care unit (ICU) stay, and duration of hospital admissions were collected. Duration of ICU stay >4 days and death were considered for the final outcomes to present the morbidity and mortality, respectively.

RESULTS

In total, the files of 1223 patients were reviewed. BSA was different between men and women, but the differences in mortality and morbidity were not statistically significant. The difference between the mean BMI in men and women was not significant (P = 0.72). In all, 11 patients (9 men, 2 women) died during the hospital stay, but no significant difference was observed between the men and the women (P = 0.59). Among the patients, 6.5% stayed >4 days in the ICU (50 men, 20 women) with no significant difference between the two (P = 0.482). No significant differences were found between the BSA and BMI of the patients who died and those who were discharged from the hospital (P = 0.088 and P = 0.321, respectively). There were no significant correlations between the duration of hospital stay and the BSA or BMI (P = 0.44 and P = 0.26, respectively).

CONCLUSION

Sex, BMI, and BSA do not affect the outcome after CABG.

Evidence-based practice guidelines for plasma transfusion

BACKGROUND

There is little systematically derived evidence-based guidance to inform plasma transfusion decisions. To address this issue, the AABB commissioned the development of clinical practice guidelines to help direct appropriate transfusion of plasma.

STUDY DESIGN AND METHODS

A systematic review (SR) and meta-analysis of randomized and observational studies was performed to quantify known benefits and harms of plasma transfusion in common clinical scenarios (see accompanying article). A multidisciplinary guidelines panel then used the SR and the GRADE methodology to develop evidence-based plasma transfusion guidelines as well as identify areas for future investigation.

RESULTS

Based on evidence ranging primarily from moderate to very low in quality, the panel developed the following guidelines: 1) The panel suggested that plasma be transfused to patients requiring massive transfusion. However, 2) the panel could not recommend for or against transfusion of plasma at a plasma : red blood cell ratio of 1:3 or more during massive transfusion, 3) nor could the panel recommend for or against transfusion of plasma to patients undergoing surgery in the absence of massive transfusion. 4) The panel suggested that plasma be transfused in patients with warfarin therapy-related intracranial hemorrhage, 5) but could not recommend for or against transfusion of plasma to reverse warfarin anticoagulation in patients without intracranial hemorrhage. 6) The panel suggested against plasma transfusion for other selected groups of patients.

CONCLUSION

We have systematically developed evidence-based guidance to inform plasma transfusion decisions in common clinical scenarios. Data from additional randomized studies will be required to establish more comprehensive and definitive guidelines for plasma transfusion.

Is it the patient or the physician who cannot tolerate anemia? A prospective analysis in 1854 non-transfused coronary artery surgery patients

Background and objective: Low hematocrit level and transfusion may coexist during cardiopulmonary bypass and the actual impact of one on the outcome parameters may be counfounded or masked by the other. This study aims to determine the impact of the lowest hematocrit level during cardiopulmonary bypass on outcome parameters in non-transfused patients. Methods: Two thousand six hundred and thirty-two consecutive patients who underwent isolated coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass were evaluated prospectively:1854 (70.4%) patients who did not receive any red blood cells during hospital stay were included in the study. Perioperative data and outcome parameters were recorded. Outcomes were evaluated in 2 groups according to the lowest level of hematocrit (>21%: high hematocrit group, n= 1680, (91.6%) and ≤21%: low hematocrit group, n=174, (9.4%)) during cardiopulmonary bypass. Results: Overall mean lowest hematocrit level of patients was 27.7±4.4% (19.7±1.9% in the low hematocrit group, 28.5±4.1% in the high hematocrit group). The comparison of outcome parameters regarding the time on ventilator, duration of intensive care unit stay, intensive care unit re-admission, hospital re-admission, reoperation for bleeding or tamponade, low cardiac output, postoperative atrial fibrillation, stroke, creatinine level at hospital discharge, new onset renal failure, mediastinitis, pulmonary complication and mortality rates were similar in both groups. Conclusions: Our findings suggest that a lowest hematocrit level of ≤21% during cardiopulmonary bypass has no adverse impact on outcome after isolated coronary surgery in non-transfused patients.

The silent risks of blood transfusion

PURPOSE OF REVIEW

Clinical research has identified blood transfusion as an independent risk factor for immediate and long-term adverse outcomes, including an increased risk of death, myocardial infarction, stroke, renal failure, infection and malignancy. New findings have called into question the traditional assumptions clinicians utilize in evaluating the risks and benefits of blood transfusion. Appreciation of newly recognized risks is important for conserving scarce resources and optimizing patient outcomes.

RECENT FINDINGS

Recent clinical outcomes research has examined the impact of blood transfusion on critically ill patients, trauma patients, patients undergoing cardiac surgery, patients experiencing acute coronary syndromes, oncology patients and others. These studies provide additional evidence of adverse outcomes associated with blood transfusion in a wide variety of clinical contexts.

SUMMARY

The benefits of blood transfusion have never been conclusively demonstrated, but evidence of transfusion-related harm continues to accumulate. Given the transfusion triggers that currently predominate in clinical practice it appears that clinical outcomes could improve significantly with more widespread adoption of restrictive transfusion strategies.