Active Bleeding after Cardiac Surgery: A Prospective Observational Multicenter Study

Cardiac Surgical Bleeding, Transfusion, and Quality Metrics: Joint Consensus Statement by the Enhanced Recovery After Surgery Cardiac Society and Society for the Advancement of Patient Blood Management

BACKGROUND

Excessive perioperative bleeding is associated with major complications in cardiac surgery, resulting in increased morbidity, mortality, and cost.

METHODS

An international expert panel was convened to develop consensus statements on the control of bleeding and management of transfusion and to suggest key quality metrics for cardiac surgical bleeding. The panel reviewed relevant literature from the previous 10 years and used a modified RAND Delphi methodology to achieve consensus.

RESULTS

The panel developed 30 consensus statements in 8 categories, including prioritizing control of bleeding, prechest closure checklists, and the need for additional quality indicators beyond reexploration rate, such as time to reexploration. Consensus was also reached on the need for a universal definition of excessive bleeding, the use of antifibrinolytics, optimal cessation of antithrombotic agents, and preoperative risk scoring based on patient and procedural factors to identify those at greatest risk of excessive bleeding. Furthermore, an objective bleeding scale is needed based on the volume and rapidity of blood loss accompanied by viscoelastic management algorithms and standardized, patient-centered blood management strategies reflecting an interdisciplinary approach to quality improvement.

CONCLUSIONS

Prioritizing the timely control and management of bleeding is essential to improving patient outcomes in cardiac surgery. To this end, a cardiac surgical bleeding quality metric that is more comprehensive than reexploration rate alone is needed. Similarly, interdisciplinary quality initiatives that seek to implement enhanced quality indicators will likely lead to improved patient care and outcomes.

POBS-Card, a new score of severe bleeding after cardiac surgery: Construction and external validation

Objective

Bleeding after cardiac surgery leads to poor outcomes. The objective of the study was to build the PeriOperative Bleeding Score in Cardiac surgery (POBS-Card) to predict bleeding after cardiac surgery.

Methods

We conducted a retrospective cohort study in 2 academic hospitals (2016-2019). Inclusion criteria were adult patients after cardiac surgery under cardiopulmonary bypass. Exclusion criteria were heart transplantation, assistance, aortic dissection, and preoperative hemostasis diseases. Bleeding was defined by the universal definition for perioperative bleeding score ≥2. POBS-Card score was built using multivariate regression (derivation cohort, one center). The performance diagnosis was assessed using the area under the curve in a validation cohort (2 centers) and compared with other scores.

Results

In total, 1704 patients were included in the derivation cohort, 344 (20%) with bleeding. Preoperative factors were body mass index <25 kg/m2 (odds ratio [OR], 1.48 [1.14-1.93]), type of surgery (redo: OR, 1.76 [1.07-2.82]; combined: OR, 1.81 [1.19-2.74]; ascendant aorta: OR, 1.56 [1.02-2.38]), ongoing antiplatelet therapy (single: OR, 1.50 [1.09-2.05]; double: OR, 2.00 [1.15-3.37]), activated thromboplastin time ratio >1.2 (OR, 1.44 [1.03-1.99]), prothrombin ratio <60% (OR, 1.91 [1.21-2.97]), platelet count <150 g/L (OR, 1.74 [1.17-2.57]), and fibrinogen <3 g/L (OR, 1.33 [1.02-1.73]). In the validation cohort of 597 patients, the area under the curve was 0.645 [0.605-0.683] and was superior to other scores (WILL-BLEED, Papworth, TRUST, TRACK). A threshold >14 predicted bleeding with a sensitivity of 50% and a specificity of 73%.

Conclusions

POBS-Card score was superior to other scores in predicting severe bleeding after cardiac surgery. Performances remained modest, questioning the place of these scores in the perioperative strategy of bleeding-sparing.

Development of the Modern Cardiothoracic Intensive Care Unit and Current Management

The modern cardiothoracic intensive care unit (CTICU) developed as a result of advances in critical care, cardiology, and cardiac surgery. Patients undergoing cardiac surgery today are sicker, frailer, and have more complex cardiac and noncardiac morbidities. CTICU providers need to understand postoperative implications of different surgical procedures, complications that can occur in CTICU patients, resuscitation protocols for cardiac arrest, and diagnostic and therapeutic interventions such as transesophageal echocardiography and mechanical circulatory support. Optimum CTICU care requires a multidisciplinary team with collaboration between cardiac surgeons and critical care physicians with training and experience in the care of CTICU patients.

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.

Critical Preoperative Hemoglobin Value to Predict Anemia-Related Complications After Cardiac Surgery

OBJECTIVES

Preoperative anemia is frequent in patients undergoing cardiac surgery and is associated with increased postoperative complications. The purpose of this observational study was to estimate the critical preoperative hemoglobin threshold associated with the occurrence of complications after cardiac surgery.

DESIGN

A retrospective observational cohort study.

SETTING

A tertiary-care medical center from January 2019 to April 2020.

PARTICIPANTS

A total of 1,004 patients undergoing elective cardiac surgery were included.

INTERVENTIONS

None (observational study).

MEASUREMENTS AND MAIN RESULTS

The primary study endpoint was to define the hemoglobin threshold that predicted the occurrence of postoperative major complications after elective cardiac surgery. Postoperative complications were a composite criterion, including transient ischemic attack or stroke, myocardial infarction, acute kidney injury, respiratory failure, mediastinitis, or mesenteric ischemia. A discrimination threshold was determined by using receiver operating characteristic curves. The discrimination threshold for hemoglobin concentration with the best sensitivity/specificity ratio for the occurrence of postoperative complications was 13 g/dL for male patients and 11.8 g/dL for female patients. The incidence of postoperative complications was 17.2% in the total population. Independent risks were preoperative hemoglobin concentration, red blood cell transfusion, European System for Cardiac Operative Risk Evaluation II, and the type of surgery.

CONCLUSIONS

The critical preoperative hemoglobin thresholds associated with the occurrence of postoperative complications with the best sensitivity/specificity ratio were 13 g/dL for men and 11.8 g/dL for women, which were very similar to the World Health Organization criteria defining anemia.

Video-Assisted Thoracoscopic Surgery Management of Subacute Retained Blood Syndrome after Cardiac Surgery

PURPOSE

Blood loss along with inadequate evacuation after cardiac surgery leads to retained blood syndrome (RBS) in the pleural and/or pericardial cavity. Re-sternotomy is often needed for clot evacuation. Video-assisted thoracoscopic surgery (VATS) evacuation is a less-invasive procedure. However, sufficient evidence on safety and outcomes is lacking.

METHODS

Thirty patients who developed hemothorax and/or hemopericardium after cardiac surgery and underwent VATS evacuation between April 2015 and September 2020 were included in this retrospective single-center analysis.

RESULTS

The median patient age was 70 (interquartile range: IQR 62-75) years, body mass index (BMI) was 24.7 (IQR 22.8-29) kg/m2, time between initial cardiac surgery and VATS was 17 (IQR 11-21) days, 30% of the patients were female, 60% resided in the ICU, and 17% were nicotine users. Coronary artery bypass graft was the most frequent initial cardiac procedure. Median operation time was 120 (IQR 90-143) min, 23% of the patients needed an additional VATS, and the median length of hospital stay after VATS was 8 (IQR 5-14) days. All patients survived VATS, and we experienced no mortality related to the VATS procedure.

CONCLUSION

In our study, VATS for evacuation of RBS after cardiac surgery was a feasible, safe, and efficient alternative approach to re-sternotomy in selected patients.

Tranexamic acid reduces postoperative blood loss in Chinese pediatric patients undergoing cardiac surgery: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Tranexamic acid has been increasingly used for blood conservation in cardiac surgery. However, the evidence supporting the routine use of tranexamic acid in Chinese pediatric patients undergoing cardiac surgery remains weak. This meta-analysis aimed to systematically review the efficacy of tranexamic acid when applying to Chinese pediatric patients undergoing cardiac surgery.

PARTICIPANTS

Chinese pediatric patients undergoing cardiac surgery.

INTERVENTIONS

Tranexamic acid or control drugs (saline/blank).

METHODS

PUBMED, Cochrane Library, EMBASE, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Data till May 4, 2021, database search was updated on August 1. Primary outcomes of interest included postoperative bleeding, allogeneic transfusion, and reoperation for bleeding. Secondary outcomes of interest included postoperative recovery. For continuous/dichotomous variables, treatment effects were calculated as weighted mean difference (WMD)/odds ratio and 95% confidence interval.

RESULTS

A database search yielded 15 randomized controlled trials including 1641 patients, where 8 studies were allocated into non-cyanotic congenital group, 5 were allocated into cyanotic congenital group, and the other 2 were allocated into combined cyanotic/non-cyanotic group. This meta-analysis demonstrate that tranexamic acid administration can reduce the postoperative 24 hours blood loss in non-cyanotic, cyanotic, and combined cyanotic/non-cyanotic patients, the red blood cell transfusion in non-cyanotic and cyanotic patients, and the fresh frozen plasma transfusion in non-cyanotic and combined cyanotic/non-cyanotic patients.

CONCLUSION

This meta-analysis demonstrates that tranexamic acid is highly effective in reducing the blood loss in Chinese pediatric cardiac surgery, but it behaves poorly when it comes to the transfusion requirement. To further confirm this, more well-designed and adequately-powered randomized trials are needed.

Consensus Statement: Hemostasis Trial Outcomes in Cardiac Surgery and Mechanical Support

BACKGROUND

Research evaluating hemostatic agents for the treatment of clinically significant bleeding has been hampered by inconsistency and lack of standardized primary clinical trial outcomes. Clinical trials of hemostatic agents in both cardiac surgery and mechanical circulatory support, such as extracorporeal membrane oxygenation and ventricular assist devices, are examples of studies that lack implementation of universally accepted outcomes.

METHODS

A subgroup of experts convened by the National Heart, Lung, and Blood Institute and the US Department of Defense developed consensus recommendations for primary outcomes in cardiac surgery and mechanical circulatory support.

RESULTS

For cardiac surgery the primary efficacy endpoint of total allogeneic blood products (units vs mL/kg for pediatric patients) administered intraoperatively and postoperatively through day 5 or hospital discharge is recommended. For mechanical circulatory support outside the perioperative period the recommended primary outcome for extracorporeal membrane oxygenation is a 5-point ordinal score of thrombosis and bleeding severity adapted from the Common Terminology Criteria for Adverse Events version 5.0. The recommended primary endpoint for ventricular assist device is freedom from disabling stroke (Common Terminology Criteria for Adverse Events AE ≥ grade 3) through day 180.

CONCLUSIONS

The proposed composite risk scores could impact the design of upcoming clinical trials and enable comparability of future investigations. Harmonizing and disseminating global consensus definitions and management guidelines can also reduce patient heterogeneity that would confound standardized primary outcomes in future research.

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.

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

Use of laboratory testing for prediction of postoperative bleeding volume in cardiovascular surgery

BACKGROUND

Coagulopathy and following massive bleeding are complications of cardiovascular surgery, particularly occurring after procedures requiring prolonged cardiopulmonary bypass (CPB). Reliable and rapid tests for coagulopathy are desirable for guiding transfusion. Measuring multiple coagulation parameters may prove useful. The purpose of this study is to determine the laboratory parameters predicting massive bleeding.

METHODS

In a prospectively collected cohort of 48 patients undergoing cardiovascular surgery, markers of coagulation and fibrinolysis were measured using automated analyzer and their correlations with bleeding volume were determined.

RESULTS

Operation time was 318 (107-654) min. CPB time was 181 (58-501) min. Bleeding volume during surgery was 2269 (174-10,607) ml. Number of transfusion units during surgery were packed red blood cells 12 (0-30) units, fresh frozen plasma 12 (0-44) units, platelets 20 (0-60) units and intraoperative autologous blood collection 669 (0-4439) ml. Post-surgery activities of coagulation factors II (FII), FV, FVII, FVIII, FIX, FX, FXI and FXII were decreased. Values of fibrinogen, antithrombin, α2 plasmin inhibitor (α2PI) and FXIII were also decreased. Values of thrombin-antithrombin complex (TAT) were increased. Values of FII, FIX, FXI and α2PI before surgery were negatively correlated with bleeding volume (FII, r = - 0.506: FIX, r = - 0.504: FXI, r = - 0.580; α2PI, r = - 0.418). Level of FIX after surgery was negatively correlated with bleeding volume (r = - 0.445) and level of TAT after surgery was positively correlated with bleeding volume (r = 0.443).

CONCLUSIONS

These results suggest that several clinical and routine laboratory parameters of coagulation were individually associated with bleeding volume during cardiovascular surgery. Determining the patterns of coagulopathy may potentially help guide transfusion during cardiovascular surgery.

Heparin concentration in cell salvage during heparinization: a pilot study

Cell salvage is frequently used to avoid unnecessary allogeneic blood transfusions, which results in a reduction in blood transfusion volume and cost. The aspirated blood is washed with normal saline and centrifuged to recover only blood cells, salvaged blood is then made. In cardiovascular surgery, heparin is used to maintain activated clotting time over 400 seconds. Some practitioners believe that heparin remains in the salvaged blood. Therefore, we hypothesized that salvaged blood during cardiovascular surgery includes heparin. A pilot study was conducted to evaluate our hypothesis using three different salvage systems. This study was a prospective, observational, pilot study, with patients aged 20-85 years old who were scheduled for cardiovascular surgery from May 2018 to October 2018. The intent of this study was to evaluate whether salvaged blood with three different devices includes large enough quantities of heparin to influence activated clotting time in cardiovascular surgery. Between May and October 2018, 12 samples during heparinization were collected, and 12 samples of salvaged blood from 3 devices were collected after administrating protamine. The heparin concentration of the 24 samples was measured. All heparin concentrations in salvage blood sample from two devices was below the limit of measurement (0.10 IU/mL). Slightly measurable heparin was detected in salvaged blood sample from one device (mean 0.15 IU/mL). Salvaged blood during cardiovascular surgery intervention does not contain enough heparin to influence activated clotting time.

[Pathophysiology of bleeding]

Bleeding is associated with an increased morbidity and mortality. Anatomic and hemostatic causes play a central role in the pathophysiology of bleeding, with anatomic causes being by far more common. While trauma and invasive procedures are the leading causes of bleeding in surgical disciplines, gastrointestinal bleeding is the major cause of bleeding in internal medicine. Major bleedings lead to secondary homeostatic changes, which in turn not only contribute to further bleeding, but also to the pathogenesis of organ dysfunction. Acquired coagulopathies due to antithrombotic treatment or an underlying disease also contribute to the extent and the dynamics of bleeding, while hereditary bleeding disorders are seldom. The balance between the physiological pro- and anticoagulant pathway plays a significant role in the pathophysiology of bleeding and coagulation. Therefore, the pathophysiology of bleeding cannot be described by means of easily available laboratory coagulation workup. The aim of coagulation correction during the management of life-threatening bleeding is not to normalize coagulation, but rather to stop bleeding. Besides a careful clinical evaluation of the course of bleeding coupled with basic understanding of the physiology of coagulation, targeted laboratory coagulation workup can contribute to a rational coagulation treatment concept.

Recommended primary outcomes for clinical trials evaluating hemostatic blood products and agents in patients with bleeding: Proceedings of a National Heart Lung and Blood Institute and US Department of Defense Consensus Conference

ABSTRACT

High-quality evidence guiding optimal transfusion and other supportive therapies to reduce bleeding is needed to improve outcomes for patients with either severe bleeding or hemostatic disorders that are associated with poor outcomes. Alongside challenges in performing high-quality clinical trials in patient populations who are at risk of bleeding or who are actively bleeding, the interpretation of research evaluating hemostatic agents has been limited by inconsistency in the choice of primary trial outcomes. This lack of standardization of primary endpoints or outcomes decreases the ability of clinicians to assess the validity of endpoints and compare research results across studies, impairs meta-analytic efforts, and, ultimately, delays the translation of research results into clinical practice. To address this challenge, an international panel of experts was convened by the National Heart Lung and Blood Institute and the US Department of Defense on September 23 and 24, 2019, to develop expert opinion, consensus-based recommendations for primary clinical trial outcomes for pivotal trials in pediatric and adult patients with six categories in various clinical settings. This publication documents the conference proceedings from the workshop funded by the National Heart Lung and Blood Institute and the US Department of Defense that consolidated expert opinion regarding clinically meaningful outcomes across a wide range of disciplines to provide guidance for outcomes of future trials of hemostatic products and agents for patients with active bleeding.

Effect of nurse-initiated forced-air warming blanket on the reduction of hypothermia complications following coronary artery bypass grafting: a randomized clinical trial

AIMS

To evaluate the effect of postoperative forced-air warming (FAW) on the incidence of excessive bleeding (ExB), arrhythmia, acute myocardial infarction (AMI), and blood product transfusion in hypothermic patients following on-pump CABG and compare temperatures associated with the use of FAW and warming with a sheet and wool blanket.

METHODS AND RESULTS

A randomized clinical trial conducted with 200 patients undergoing isolated on-pump CABG from January to November 2018. Patients were randomly assigned into an Intervention Group (IG, FAW, n = 100) and Control Group (CG, sheet and blanket, n = 100). The tympanic temperature of all patients was measured over a 24-h period. ExB was the primary outcome, while arrhythmia, AMI, and blood product transfusion were secondary outcomes. The effect of the interventions on the outcomes was investigated through using bivariate logistic regression, with a level of significance of 5%. The IG was 79% less likely to experience bleeding than the CG [odds ratio (OR) = 0.21, confidence interval (CI) 95% 0.12-0.39, P < 0.001]; the occurrence of AMI in the IG was 94% lower than that experienced by the CG (OR = 0.06, CI 95% 0.01-0.48, P < 0.001); and the IG was also 77% less likely to experience arrhythmia than the CG (OR = 0.23, CI 95% 0.12-0.47, P < 0.001); no difference was found between groups in terms of blood product transfusion (P < 0.279).

CONCLUSIONS

These findings show that FAW can be used following CABG until patients reach normothermia to avoid undesirable clinical outcomes.

TRIAL REGISTRATION

REBeC RBR-5t582g.

Re-exploration for bleeding after cardiac surgery: revaluation of urgency and factors promoting low rate

BACKGROUND

Re-exploration of bleeding after cardiac surgery is associated with significant morbidity and mortality. Perioperative blood loss and rate of re-exploration are variable among centers and surgeons.

OBJECTIVE

To present our experience of low rate of re-exploration based on adopting checklist for hemostasis and algorithm for management.

METHODS

Retrospective analysis of medical records was conducted for 565 adult patients who underwent surgical treatment of congenital and acquired heart disease and were complicated by postoperative bleeding from Feb 2006 to May 2019. Demographics of patients, operative characteristics, perioperative risk factors, blood loss, requirements of blood transfusion, morbidity and mortality were recorded. Logistic regression was used to identify predictors of re-exploration and determinants of adverse outcome.

RESULTS

Thirteen patients (1.14%) were reexplored for bleeding. An identifiable source of bleeding was found in 11 (84.6%) patients. Risk factors for re-exploration were high body mass index, high Euro SCORE, operative priority (urgent/emergent), elevated serum creatinine and low platelets count. Re-exploration was significantly associated with increased requirements of blood transfusion, adverse effects on cardiorespiratory state (low ejection fraction, increased s. lactate, and prolonged period of mechanical ventilation), longer intensive care unit stay, hospital stay, increased incidence of SWI, and higher mortality (15.4% versus 2.53% for non-reexplored patients). We managed 285 patients with severe or massive bleeding conservatively by hemostatic agents according to our protocol with no added risk of morbidity or mortality.

CONCLUSION

Low rate of re-exploration for bleeding can be achieved by strict preoperative preparation, intraoperative checklist for hemostasis implemented by senior surgeons and adopting an algorithm for management.

The effect of non-point-of-care haemostasis management protocol implementation in cardiac surgery: A systematic review

Objectives

This systematic review aims to outline the evidence on the implementation of a non‐point‐of‐care (non‐point‐of‐care [POC]) haemostasis management protocol compared to experience‐based practice in adult cardiac surgery.

Background

Management of coagulopathy in cardiac surgery is complex and remains highly variable among centres and physicians. Although various guidelines recommend the implementation of a transfusion protocol, the literature on this topic has never been systematically reviewed.

Methods

PubMed, Embase, Cochrane Library, and Web of Science were searched from January 2000 till May 2020.

Results

A total of seven studies (one randomised controlled trial [RCT], one prospective cohort study, and five retrospective studies) met the inclusion criteria. Among the six non‐randomised, controlled studies, the risk of bias was determined to be serious to critical, and the one RCT was determined to have a high risk of bias. Five studies showed a significant reduction in red blood cells, fresh frozen plasma, and/or platelet transfusion after the implementation of a structural non‐POC algorithm, ranging from 2% to 28%, 2% to 19.5%, and 7% to17%, respectively. One study found that fewer patients required transfusion of any blood component in the protocol group. Another study had reported a significantly increased transfusion rate of platelet concentrate in the haemostasis algorithm group.

Conclusion

Owing to the high heterogeneity and a substantial risk of bias of the included studies, no conclusion can be drawn on the additive value of the implementation of a cardiac‐surgery‐specific non‐POC transfusion and haemostasis management algorithm compared to experience‐based practice. To define the exact impact of a transfusion protocol on blood product transfusion, bleeding, and adverse events, well‐designed prospective clinical trials are required.

Barriers and facilitators to implementing evidence based bleeding management in Australian Cardiac Surgery Units: a qualitative interview study analysed with the theoretical domains framework and COM-B model

Background

Bleeding during cardiac surgery is a common complication that often requires the transfusion of blood products. The combination of bleeding and blood product transfusion incrementally increases adverse outcomes including infection and mortality. Following bleeding management guideline recommendations could assist with minimising risk but adherence is not high, and the cause for lack of adherence is not well understood. This study aimed to identify barriers and facilitators to practicing and implementing evidenced-based intra-operative, bleeding management in Australian cardiac surgery units.

Methods

We used a qualitative descriptive design to conduct semi-structured interviews with Australian cardiac surgeons, anaesthetists and perfusionists. The Theoretical Domains Framework (TDF) was utilised to guide interviews and thematically analyse the data. Categorised data were then linked with the three key domains of the COM-B model (capability, opportunity, motivation - behaviour) to explore and understand behaviour.

Results

Seventeen interviews were completed. Nine of the 14 TDF domains emerged as significant. Analysis revealed key themes to improving capability included, standardisation, monitoring, auditing and feedback of data and cross discipline training. Opportunity for change was improved with interpersonal and interdepartmental collaboration through shared goals, and more efficient and supportive processes allowing clinicians to navigate unfamiliar business and financial models of health care. Results suggest as individuals, clinicians had the motivation to make change and healthcare organisations have an obligation and a responsibility to partner with clinicians to support change and improve goal directed best practice.

Conclusion

Using a theory-based approach it was possible to identify factors which may be positively or negatively influence clinicians ability to implement best practice bleeding management in Australian cardiac surgical units.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06269-8.

Patient blood management in India - Review of current practices and feasibility of applying appropriate standard of care guidelines. A position paper by an interdisciplinary expert group

In a developing country like India, with limited resources and access to healthcare facilities, dealing with massive hemorrhage is a major challenge. This challenge gets compounded by pre-existing anemia, hemostatic disorders, and logistic issues of timely transfer of such patients from peripheral hospitals to centers with adequate resources and management expertise. Despite the awareness amongst healthcare providers regarding management modalities of bleeding patients, no uniform Patient Blood Management (PBM) or perioperative bleeding management protocols have been implemented in India, yet. In light of this, an interdisciplinary expert group came together, comprising of experts working in transfusion medicine, hematology, obstetrics, anesthesiology and intensive care, to review current practices in management of bleeding in Indian healthcare institutions and evaluating the feasibility of implementing uniform PBM guidelines. The specific intent was to perform a gap analysis between the ideal and the current status in terms of practices and resources. The expert group identified interdisciplinary education in PBM and bleeding management, bleeding history, viscoelastic and platelet function testing, and the implementation of validated, setting-specific bleeding management protocols (algorithms) as important tools in PBM and perioperative bleeding management. Here, trauma, major surgery, postpartum hemorrhage, cardiac and liver surgery are the most common clinical settings associated with massive blood loss. Accordingly, PBM should be implemented as a multidisciplinary and practically applicable concept in India in a timely manner in order to optimize the use the precious resource blood and to increase patients' safety.

Device-Induced Hemostatic Disorders in Mechanically Assisted Circulation

Mechanically assisted circulation (MAC) sustains the blood circulation in the body of a patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) or on ventricular assistance with a ventricular assist device (VAD) or on extracorporeal membrane oxygenation (ECMO) with a pump-oxygenator system. While MAC provides short-term (days to weeks) support and long-term (months to years) for the heart and/or lungs, the blood is inevitably exposed to non-physiological shear stress (NPSS) due to mechanical pumping action and in contact with artificial surfaces. NPSS is well known to cause blood damage and functional alterations of blood cells. In this review, we discussed shear-induced platelet adhesion, platelet aggregation, platelet receptor shedding, and platelet apoptosis, shear-induced acquired von Willebrand syndrome (AVWS), shear-induced hemolysis and microparticle formation during MAC. These alterations are associated with perioperative bleeding and thrombotic events, morbidity and mortality, and quality of life in MCS patients. Understanding the mechanism of shear-induce hemostatic disorders will help us develop low-shear-stress devices and select more effective treatments for better clinical outcomes.

MiR-223 levels predicting perioperative bleeding in off-pump coronary artery bypass grafting

Background

To investigate the predictive value of platelet-related microRNAs (miRNAs) for bleeding during and after off-pump coronary artery bypass grafting (OPCABG) and the influence of dual antiplatelet therapy (DAPT) on miRNAs.

Methods

This prospective study included 59 patients scheduled for OPCABG. The plasma miR-126 and miR-223 levels were measured and platelet aggregation was determined by thromboelastography during DAPT. The plasma miRNA levels were compared between patients treated with ticagrelor or clopidogrel. Multivariable logistic regression analysis was performed to determine the independent risk factors for bleeding during and after surgery. Active bleeding 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 during the first 12 postoperative hours. Severe perioperative bleeding was defined using the universal definition of perioperative bleeding in adult cardiac surgery.

Results

Higher circulating miR-223 levels [odds ratio (OR) =1.348, 95% confidence interval (CI): 1.001–1.814, P=0.047] and lower body mass index (OR =0.648, 95% CI: 0.428–0.980, P=0.040) were independent predictors for severe perioperative bleeding in OPCABG. Ticagrelor treatment led to significant increases in circulating miR-223 levels compared with clopidogrel treatment.

Conclusions

The plasma miR-223 levels served as a predictor for bleeding during and after OPCABG. Circulating miR-223 levels were significantly elevated with ticagrelor treatment compared with clopidogrel treatment. MiR-223 may be a novel biomarker for bleeding in cardiac surgery and can help explain the different efficacies of ticagrelor and clopidogrel.

Gelatin and the risk of bleeding after cardiac surgery

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Preoperative Anemia as a Risk Factor for Postoperative Outcomes in Patients Undergoing Lung Transplantation

OBJECTIVES

The aim of this study was to evaluate the effect of preoperative anemia on early postoperative outcomes in a population of patients undergoing lung transplantation.

DESIGN

Single-center retrospective study of lung transplantation recipients between April 2013 and June 2018. The primary outcome was hospital length of stay.

SETTING

Ronald Reagan UCLA Medical Center, Los Angeles, CA, a tertiary academic medical center.

PARTICIPANTS

Patients presenting from home for lung transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 435 patients underwent lung transplantation during the study period. After exclusion, 342 were included in the analysis. The prevalence of preoperative anemia was 54% (n = 183); however, only 11% of anemic patients received treatment for anemia before transplantation. Multivariate regression analysis indicated that lower hemoglobin levels were associated with longer hospital lengths of stay (p = 0.049). Preoperative anemia also was independently associated with an increased risk for redo surgery for bleeding (odds ratio 4.89; p = 0.007). No association between preoperative anemia and any of the other postoperative outcomes examined was found.

CONCLUSIONS

Preoperative anemia in patients undergoing lung transplantation is undertreated and independently associated with an increased risk for redo surgery for bleeding. Additional studies regarding reasons for this association and effect of treatment are necessary to improve outcomes.

Blood Loss Kinetics During the First 12 Hours After On-Pump Cardiac Surgical Procedures

BACKGROUND

Anemia and coagulation management and a restrictive transfusion strategy are key points of blood management in patients undergoing cardiac surgical procedures. However, little consideration has been given to the kinetics of postoperative bleeding. This prospective observational study investigated bleeding kinetics from chest tubes to assess whether it was possible to predict, within the early postoperative hours, major bleeding at 12 postoperative hours.

METHODS

Adult cardiac surgical patients who were admitted consecutively to the postoperative intensive care unit in a tertiary academic hospital from January to June 2016 were included. Blood volume was collected from the chest drains, and major bleeding was defined as bleeding exceeding the 90th percentile of the volume distribution at 12 postoperative hours. Receiver operating characteristics curve analysis was performed with hourly bleeding thresholds to determine the best predictor of major bleeding.

RESULTS

In 292 patients, bleeding at 12 postoperative hours ranged from 60 to 2190 mL (median, 350 mL), and 30 patients had major bleeding, with a threshold of 675 mL. Bleeding volume declined logarithmically, 54% [IQR, 45% to 63%] within the first 4 hours. Patients with major bleeding had a higher bleeding volume every hour (P < .004). A good predictive value was observed within the first 2 hours (2.73 mL/kg; receiver operating characteristics area under the curve, 0.87 ± 0.04 [IQR, 0.79 to 0.94]; P< .001).

CONCLUSIONS

The hourly rate of chest tube blood loss seems to be relevant to predict, within the first postoperative hours after cardiac surgical procedures, major bleeding at 12 postoperative hours. Early detection of blood loss may help to improve a patient's blood conservation strategy because it may prompt preemptive treatments.

Modern Management of Bleeding, Clotting, and Coagulopathy in Trauma Patients: What Is the Role of Viscoelastic Assays?

Purpose of Review

The purpose of this review is to briefly outline the current state of hemorrhage control and resuscitation in trauma patients with a specific focus on the role viscoelastic assays have in this complex management, to include indications for use across all phases of care in the injured patient.

Recent Findings

Viscoelastic assay use to guide blood-product resuscitation in bleeding trauma patients can reduce mortality by up to 50%. Viscoelastic assays also reduce total blood products transfused, reduce ICU length of stay, and reduce costs. There are a large number of observational and retrospective studies evaluating viscoelastic assay use in the initial trauma resuscitation, but only one randomized control trial. There is a paucity of data evaluating use of viscoelastic assays in the operating room, post-operatively, and during ICU management in trauma patients, rendering their use in these settings extrapolative/speculative based on theory and data from other surgical disciplines and settings.

Summary

Both hypocoagulable and hypercoagulable states exist in trauma patients, and better indicate what therapy may be most appropriate. Further study is needed, particularly in the operating room and post-operative/ICU settings in trauma patients.

Bleeding Management Practices of Australian Cardiac Surgeons, Anesthesiologists and Perfusionists: A Cross-Sectional National Survey Incorporating the Theoretical Domains Framework (TDF) and COM-B Model

Purpose

Excessive bleeding is an acknowledged consequence of cardiac surgery, occurring in up to 10% of adult patients. This clinically important complication leads to poorer patient outcomes. Clinical practice guidelines are available to support best practice however variability in bleeding management practice and related adverse outcomes still exist. This study had two objectives: 1) to gain insight into current bleeding management practice for adult cardiac surgery in Australia and how that compared to guidelines and literature; and 2) to understand perceived difficulties clinicians face implementing improvements in bleeding management.

Methods

A national cross-sectional questionnaire survey was utilized. Perspectives were sought from cardiac surgeons, cardiac anesthesiologists and perfusionists. Thirty-nine closed-ended questions focused on routine bleeding management practices to address pre and intra-operative care. One open-ended question was asked; “What would assist you to improve bleeding management with cardiac surgery patients?” Quantitative data were analysed with SPSS. Qualitative data were categorized into the domains of the Theoretical Domains Framework; the domains were then mapped to the COM-B model.

Results

Survey responses from 159 Anesthesiologists, 39 cardiac surgeons and 86 perfusionists were included (response rate 37%). Four of the recommendations queried in this survey were reported as routinely adhered to < 50% of the time, 9 queried recommendations were adhered to 51–75% of the time and 4 recommendations were routinely followed >76% of the time.

Conclusion

There is a wide variation in peri-operative bleeding management practice among cardiac anaesthesiologists, surgeons and perfusionists in Australian cardiac surgery units. Conceptualizing factors believed necessary to improve practice with the TDF and COM-B model found that bleeding management could be improved with a standardized approach including; point of care diagnostic assays, a bleeding management algorithm, access to concentrated coagulation factors, cardiac surgery specific bleeding management education, multidisciplinary team agreement and support, and an overarching national approach.

Optimizing Perioperative Blood and Coagulation Management During Cardiac Surgery

Bleeding and transfusion are common in cardiac surgery and associated with poorer outcome. Bleeding is frequently due to coagulopathy caused by the complex interaction between cardiopulmonary bypass, major surgical trauma, anticoagulation management, and perioperative factors. Patient blood management has emerged to improve outcome by the prediction, prevention, monitoring, and treatment of bleeding and transfusion. Each part of this chain has several individual modalities and when combined leads to result in a better outcome. This article reviews the hemostasis disturbances in cardiac surgery with cardiopulmonary bypass and gives an overview of the most important patient blood management strategies.

Factor XIII activity in patients requiring surgical re-exploration for bleeding after elective cardiac surgery - A prospective case control study

PURPOSE

Surgical re-exploration due to postoperative bleeding is associated with increased morbidity and mortality. The aim of our study was to assess a potential association between the level of postoperative FXIII activity and need for re-exploration due to bleeding in patients undergoing cardiothoracic surgery.

MATERIALS AND METHODS

In our prospective single center observational cohort study, we enrolled patients who underwent elective cardiothoracic surgery. Patients who required re-exploration (RE group) were matched to patients from the study population (non-RE group).

RESULTS

The study included 64 patients, out of a cohort of 678 patients, of whom 32 required surgical re-exploration due to bleeding within the first 24 h. Between patients of the RE and non-RE group, a significantly reduced FXIII activity was observed postoperatively (59.0 vs 71.1; p = .014). Multivariable analysis revealed reduced FXIII activity (p = .048) as a parameter independently associated with surgical re-exploration. Further, reduced FXIII activity (p = .037) and surgical re-exploration (p = .01) were significantly associated with increased 30 day mortality. In multivariable analysis re-exploration was independently associated with increased risk of 30 day mortality (p = .004, HR 9.68).

CONCLUSIONS

Reduced postoperative FXIII activity may be associated with the need for surgical re-exploration. Postoperative assessment of FXIII activity should therefore be considered in patients undergoing elective cardiothoracic surgery.

Tranexamic acid in cardiac surgery: a systematic review and meta-analysis (protocol)

INTRODUCTION

Bleeding during cardiac surgery is associated with increased morbidity and mortality. Tranexamic acid is an antifibrinolytic with proven efficacy in major surgeries. Current clinical practice guidelines recommend intraoperative use in cardiac procedures. However, several complications have been reported with tranexamic acid including seizures. This review intends to summarise the evidence examining the efficacy and safety of tranexamic acid in patients undergoing cardiac surgery.

METHODS/DESIGN

We will search MEDLINE, Embase, PubMED, ACPJC, CINAHL and the Cochrane trial registry for eligible randomised controlled trials, the search dates for all databases will be from inception until 1 January 2019, investigating the perioperative use of topical and/or intravenous tranexamic acid as a stand-alone antifibrinolytic agent compared with placebo in patients undergoing open cardiac surgery. We categorised outcomes as patient critical or patient important. Selected patient-critical outcomes are: mortality (intensive care unit, hospital and 30-day endpoints), reoperation within 24 hours, postoperative bleeding requiring transfusion of packed red blood cells, myocardial infarction, stroke, pulmonary embolism, bowel infarction, upper or lower limb deep vein thrombosis and seizures. Those outcomes, we perceived as clinical experts to be most patient valued and patients were not involved in outcomes selection process. We will not apply publication date, language, journal or methodological quality restrictions. Two reviewers will independently screen and identify eligible studies using predefined eligibility criteria and then review full reports of all potentially relevant citations. A third reviewer will resolve disagreements if consensus cannot be achieved. We will present the results as relative risk with 95% CIs for dichotomous outcomes and as mean difference or standardised mean difference for continuous outcomes with 95% CIs. We will assess the quality of evidence using the Grading of Recommendations, Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as primary data will not be collected. The results will be disseminated through a peer-reviewed publication TRIAL REGISTRATION NUMBER: CRD42018105904.

Outcome of cardiac surgery in adults with congenital heart disease: A single center experience

Objectives

Adult survivors with congenital heart diseases represent a large and growing population, yet the published data does not represent the magnitude of their needs specifically in the Middle East. We aimed to review our experience at King Faisal Heart Center, Riyadh, Saudi Arabia for the outcome of adult patients with congenital heart disease who underwent either primary or redo surgery.

Methods

A retrospective study at a tertiary care hospital. All patients who underwent surgery either as the first surgery or as a reoperation for congenital heart disease aged >16 years old at the time of cardiac surgery in the period between January 1, 2008 and January 1, 2013. We looked for incidence of postoperative bleeding, arrhythmias, acute kidney injury, neurological complications, duration of mechanical ventilation, hospital and intensive care unit (ICU) stay. Additionally, we assessed the mortality and 1- and 5-year survival.

Results

Ninety-eight patients were included in our study. Fifty-two (53%) were females and 46 (47%) were males, with a mean age of 26 ± 8.4 years and a mean weight of 62 ± 22.8 kg. Forty-nine patients (50%) required redo surgery. Ten patients (10%) suffered from postoperative bleeding. Eight patients (8%) had postoperative arrhythmias, of which two patients required permanent pacemaker insertion. Three patients (3%) had postoperative acute kidney injury and seven patients (7%) suffered from neurological complications. The mean duration of ventilation was 1.3 ± 2 days, with a mean ICU and hospital stay of 3.7 ± 3 days, and 10 ± 7 days, respectively. The overall mortality rate in our series was 4% with a 1–5-year survival of 96%.

Conclusion

Adult patients with congenital heart disease are prone to immediate postoperative multisystem complications, yet the majority of them are reversible. Their 1- and 5-year survival rate is excellent. Further follow up studies are required.

Impact of bleeding complications on length of stay and critical care utilization in cardiac surgery patients in England

Background

Bleeding is a significant complication in cardiac surgery and is associated with substantial morbidity and mortality. This study evaluated the impact of bleeding on length of stay (LOS) and critical care utilization in a nationwide sample of cardiac surgery patients treated at English hospitals.

Methods

Retrospective, observational cohort study using linked English Hospital Episode Statistics (HES) and Clinical Practice Research Datalink (CPRD) records for a nationwide sample of patients aged ≥18 years who underwent coronary artery bypass graft (CABG), valve repair/replacement, or aortic operations from January 2010 through February 2016. The primary independent variables were in-hospital bleeding complications and reoperation for bleeding before discharge. Generalized linear models were used to quantify the adjusted mean incremental difference [MID] in post-procedure LOS and critical care days associated with bleeding complications, independent of measured baseline characteristics.

Results

The study included 7774 cardiac surgery patients (3963 CABG; 2363 valve replacement/repair; 160 aortic procedures; 1288 multiple procedures, primarily CABG+valve). Mean LOS was 10.7d, including a mean of 4.2d in critical care. Incidences of in-hospital bleeding complications and reoperation for bleeding were 6.7 and 0.3%, respectively. Patients with bleeding had longer LOS (MID: 3.1d; p < 0.0001) and spent more days in critical care (MID: 2.4d; p < 0.0001). Reoperation for bleeding was associated with larger increases in LOS (MID = 4.0d; p = 0.002) and days in critical care (MID = 3.2d; p = 0.001).

Conclusions

Among English cardiac surgery patients, in-hospital bleeding complications were associated with substantial increases in healthcare utilization. Increased use of evidence-based strategies to prevent and manage bleeding may reduce the clinical and economic burden associated with bleeding complications in cardiac surgery.

Electronic supplementary material

The online version of this article (10.1186/s13019-019-0881-3) contains supplementary material, which is available to authorized users.

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.

Factors associated with the increased bleeding in the postoperative period of cardiac surgery: A cohort study

AIMS AND OBJECTIVES

To identify factors associated with the increased bleeding in patients during the postoperative period after cardiac surgery.

BACKGROUND

Bleeding is among the most frequent complications that occur in the postoperative period after cardiac surgery, representing one of the major factors in morbidity and mortality. Understanding the factors associated with the increased bleeding may allow nurses to anticipate and prioritise care, thus reducing the mortality associated with this complication.

DESIGN

Prospective cohort study.

METHODS

Adult patients in a cardiac hospital who were in the postoperative period following cardiac surgery were included. Factors associated with the increased bleeding were investigated by means of linear regression, considering time intervals of 6 and 12 hr.

RESULTS

The sample comprised 391 participants. The factors associated with the increased bleeding in the first 6 hr were male sex, body mass index, cardiopulmonary bypass duration, anoxia duration, metabolic acidosis, higher heart rate, platelets and the activated partial thromboplastin time in the postoperative period. Predictors in the first 12 hr were body mass index, cardiopulmonary bypass duration, metabolic acidosis, higher heart rate, platelets and the activated partial thromboplastin time in the postoperative.

CONCLUSIONS

This study identified factors associated with the increased postoperative bleeding from cardiac surgery that have not been reported in previous studies. The nurse is important in the vigilance, evaluation and registry of chest tube drainage and modifiable factors associated with the increased bleeding, such as metabolic acidosis and postoperative heart rate, and in discussions with the multiprofessional team.

RELEVANCE TO CLINICAL PRACTICE

Knowledge of the factors associated with the increased bleeding is critical for nurses so they can provide prophylactic interventions and early postoperative treatment when needed.

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.