Predictive factors for bleeding-related re-exploration after cardiac surgery: A prospective cohort study

Development and validation of a postoperative bleeding complications prediction model in infective endocarditis

OBJECTIVES

Bleeding complications are one of the most serious postoperative complications after cardiac surgery and are associated with high mortality, especially in patients with infective endocarditis (IE). Our objectives were to identify the risk factors and develop a prediction model for postoperative bleeding complications in IE patients.

METHODS

The clinical data of IE patients treated from October 2013 to January 2022 were reviewed. Multivariate logistic regression analysis was used to evaluate independent risk factors for postoperative bleeding complications and develop a prediction model accordingly. The prediction model was verified in a temporal validation cohort. The performance of the model was evaluated in terms of its discrimination power, calibration, precision, and clinical utility.

RESULTS

A total of 423 consecutive patients with IE who underwent surgery were included in the final analysis, including 315 and 108 patients in the training cohort and validation cohort, respectively. Four variables were selected for developing a prediction model, including platelet counts, systolic blood pressure, heart failure and vegetations on the mitral and aortic valves. In the training cohort, the model exhibited excellent discrimination power (AUC = 0.883), calibration (Hosmer-Lemeshow test, P = 0.803), and precision (Brier score = 0.037). In addition, the model also demonstrated good discrimination power (AUC = 0.805), calibration (Hosmer-Lemeshow test, P = 0.413), and precision (Brier score = 0.067) in the validation cohort.

CONCLUSIONS

We developed and validated a promising risk model with good discrimination power, calibration, and precision for predicting postoperative bleeding complications in IE patients.

Impact of intraoperative blood products, fluid administration, and persistent hypothermia on bleeding leading to reexploration after cardiac surgery

OBJECTIVE

Risk factors for severe postoperative bleeding after cardiac surgery remain multiple and incompletely elucidated. We evaluated the impact of intraoperative blood product transfusions, intravenous fluid administration, and persistently low core body temperature (CBT) at intensive care unit arrival on risk of perioperative bleeding leading to reexploration.

METHODS

We retrospectively queried our tertiary care center's Society of Thoracic Surgeons Institutional Database for all index, on-pump, adult cardiac surgery patients between July 2016 and September 2022. Intraoperative fluid (crystalloid and colloid) and blood product administrations, as well as perioperative CBT data, were harvested from electronic medical records. Linear and nonlinear mixed models, treating surgeon as a random effect to account for inter-surgeon practice differences, were used to assess the association between above factors and reexploration for bleeding.

RESULTS

Of 4037 patients, 151 (3.7%) underwent reexploration for bleeding. Reexplored patients experienced remarkably greater postoperative morbidity (23% vs 6%, P < .001) and 30-day mortality (14% vs 2%, P < .001). In linear models, progressively increasing IV crystalloid administration (adjusted odds ratio, 1.11, 95% confidence interval, 1.03-1.19) and decreasing CBT on intensive care unit arrival (adjusted odds ratio, 1.20; 95% confidence interval, 1.05-1.37) were associated with greater risk of bleeding leading to reexploration. Nonlinear analysis revealed increasing risk after ∼6 L of crystalloid administration and a U-shaped relationship between CBT and reexploration risk. Intraoperative blood product transfusion of any kind was not associated with reexploration.

CONCLUSIONS

We found evidence of both dilution- and hypothermia-related effects associated with perioperative bleeding leading to reexploration in cardiac surgery. Interventions targeting modification of such risk factors may decrease the rate this complication.

Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass?

BACKGROUND

Heparin rebound is a common observed phenomenon after cardiac surgery with CPB and is associated with increased postoperative blood loss. However, the administration of extra protamine may lead to increased blood loss as well. Therefore, we want to investigate the relation between heparin rebound and postoperative blood loss and the necessity to provide extra protamine to reverse heparin rebound.

METHODS

We searched PubMed, Cochrane, EMBASE, Google Scholar and Web of Science to review the question: "Does heparin rebound lead to postoperative blood loss in patients undergoing cardiac surgery with cardiopulmonary bypass." Combination of search words were framed within four major categories: heparin rebound, blood loss, cardiac surgery and cardiopulmonary bypass. All studies that met our question were included. Quality assessment was performed using the Cochrane risk of bias (RoB2) tool for randomized controlled trials and the risk of bias in non-randomized studies of intervention (ROBINS-I) for non-randomised trials.

RESULTS

4 randomized and 17 non-randomized studies were included. The mean incidence of heparin rebound was 40%. The postoperative heparin levels, due to heparin rebound, were often below or equal to 0.2 IU/mL. We could not demonstrate an association between heparin rebound and postoperative blood loss or transfusion requirements. However the quality of evidence was poor due to a broad variety of definitions of heparin rebound, measured by various coagulation tests and studies with small sample sizes.

CONCLUSION

The influence of heparin rebound on postoperative bleeding seems to be negligible, but might get significant in conjunction with incomplete heparin reversal or other coagulopathies. For that reason, it might be useful to get a picture of the entire coagulation spectrum after cardiac surgery, as can be done by the use of a viscoelastic test in conjunction with an aggregometry test.

Reoperation for bleeding after cardiac surgery

BACKGROUND

Postoperative cardio-surgical haemostatic management is centre-specific and experience-based, which leads to a variability in patient care. This study aimed to identify which postoperative haemostatic interventions may reduce the need for reoperation after cardiac surgery in adults.

METHODS

A retrospective case-control study in a tertiary centre. Adult, elective, primary cardiac surgical patients were selected (n = 2098); cases (n = 42) were patients who underwent reoperation within 72 h after the initial surgery. Interventions administered to control surgical bleeding were compared for the need to re-operate using multiple logistic regression.

RESULTS

Rate of cardiac surgical reoperation was 2% in the study population. Three variables were found to be associated with cardiac reoperation: preoperative administration of fresh frozen plasma (OR 5.45, CI 2.34-12.35), cumulative volume of chest tube drainage and cumulative count of packed red blood cells transfusion on ICU (OR 1.98, CI 1.56-2.51).

CONCLUSION

No significant difference among specific types of postoperative haemostatic interventions was found between patients who needed reoperation and those who did not. Perioperative transfusion of fresh frozen plasma, postoperative transfusion of packed cells and cumulative volume of chest tube drainage were associated with reoperation after cardiac surgery. These variables could help predict the need for reoperation.

Factors associated with reoperation due to bleeding and outcomes after cardiac surgery: a prospective cohort study

OBJECTIVE

Identify the incidence and factors associated with reoperation due to bleeding in the postoperative of a cardiac surgery, in addition to the clinical outcomes of patients.

METHOD

Prospective cohort study, conducted in an Intensive Care Unit (ICU), with adult patients undergoing cardiac surgery. Patients diagnosed with coagulopathies were excluded. The patients were followed up from hospitalization to hospital discharge.

RESULTS

A total of 682 patients were included, and the incidence of reoperation was 3.4%. The factors associated with reoperation were history of renal failure (p = 0.005), previous use of anticoagulant (p = 0.036), higher intraoperative heart rate (p = 0.015), need for transfusion of blood component during intraoperative (p = 0.040), and higher SAPS 3 score (p < 0.001). The outcomes associated with reoperation were stroke and cardiac arrest.

CONCLUSÃO

Reoperation was an event associated with greater severity, organic dysfunction, and worse clinical outcomes, but there was no difference in mortality between the groups.

Fatores associados à reoperação por sangramento e desfechos após cirurgia cardíaca: estudo de coorte prospectivo

RESUMO Objetivo: Identificar a incidência e os fatores associados à reoperação devido sangramento no pós-operatório de cirurgia cardíaca, além dos desfechos clínicos dos pacientes. Método: Estudo de coorte prospectivo, realizado em Unidade de Terapia Intensiva (UTI), com pacientes adultos submetidos à cirurgia cardíaca. Foram excluídos pacientes com diagnóstico de coagulopatias. Os pacientes foram acompanhados desde a internação até a saída hospitalar. Resultados: Foram incluídos 682 pacientes e a incidência de reoperação foi 3,4 %. Os fatores associados à reoperação foram: histórico de insuficiência renal (p = 0,005), uso prévio de anticoagulante (p = 0,036), maior frequência cardíaca intraoperatória (p = 0,015), necessidade de transfusão de hemocomponentes no intraoperatório (p = 0,040) e maior pontuação no SAPS 3 (p < 0,001). Os desfechos associados a reoperação foram: acidente vascular encefálico e parada cardiorrespiratória. Conclusão: A reoperação foi um evento associado a maior gravidade, disfunção orgânica, e piores desfechos clínicos, porém não houve diferença de mortalidade entre os grupos.

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 death risk factors of patients undergoing re-exploration for bleeding or tamponade after isolated off-pump coronary artery bypass grafting: a case-control study

Background

The purpose of the study is to identify off-pump patients who are at higher risk of mortality after re-exploration for bleeding or tamponade.

Methods

We analyzed the data of 3256 consecutive patients undergoing isolated off-pump coronary artery bypass grafting (OPCABG) in our heart center from 2013 through 2020. Fifty-eight patients underwent re-exploration after OPCABG. The 58 patients were divided into death group and survival group according to their discharge status. Propensity score matching (PSM) was performed to analysis the risk factors of death. 15 pairs of cases of two groups were matched well.

Results

The mortality rate of patients underwent re-exploration after OPCABG for bleeding or tamponade was 27.59% (16/58). In the raw data, we found the patients in death group had higher body mass index (BMI) (P = 0.030), higher cardiac troponin T (cTnT) (P = 0.028) and higher incidence of heart failure before OPCABG (P = 0.003). After PSM, the levels of lactic acid before and after re-exploration (P = 0.028 and P < 0.001) were higher in death group. And the levels of creatinine (P = 0.002) and cTnT (P = 0.017) were higher in the death group after re-exploration. The death group had longer reoperation time (P = 0.010). In addition, the perioperative utilization rate of intra-aortic ballon pump (IABP) (P = 0.027), continuous renal replacement therapy (CRRT) (P < 0.001) and platelet transfusion (P = 0.017) were higher than survival group.

Conclusions

The mortality rate of patients undergoing re-exploration for bleeding or tamponade after isolated OPCABG is high. More attention should be paid to patients with above risk factors and appropriate measures should be taken in time.

Too Cold to Clot? Does Intraoperative Hypothermia Contribute to Bleeding After Aortic Surgery?

Background

We determined the impact of intraoperative hypothermia on postoperative bleeding after thoracic aortic surgery.

Methods

We retrospectively analyzed 98 consecutive patients who underwent aortic surgery with deep hypothermic circulatory arrest between 2010 and 2014. We evaluated lowest temperature, absolute decrease in temperature, and rewarming rate. Univariate and multivariate regression were used to determine relationships between temperature, clinical characteristics, and measures of postoperative bleeding.

Results

The mean age of patients was 60.5 ± 15.1 years, with 64.3% male and 60% Caucasian. The lowest temperatures recorded were 13.5 ± 4.6°C at the bypass circuit. Change in hematocrit was associated with ethnicity, preoperative hematocrit, and rewarming rate. Chest tube output was associated with body mass index, preoperative platelet count, prior cardiac surgery, cardiopulmonary bypass (CPB) duration, intraoperative blood product transfusion, lowest surface temperature, and change in surface temperature. Postoperative packed red blood cell transfusion was associated with ejection fraction, chronic obstructive pulmonary disease (COPD), platelet count, partial thromboplastin time, CPB duration, and lowest blood temperature. Fresh frozen plasma transfusion correlated with COPD, CPB duration, and final blood temperature. Platelet transfusion correlated with body mass index and preoperative platelet count. Unplanned reoperation for bleeding was associated with final temperature and change in temperature.

Conclusion

We found no consistent associations between intraoperative temperature and indicators of bleeding. Intraoperative cooling strategies should be based on optimal end-organ protection rather than fear of postoperative bleeding; rewarming strategies may ameliorate the risk of coagulopathy.

Meta-analysis of the Sources of Bleeding after Adult Cardiac Surgery

OBJECTIVE

The aim of this study was to pool data on the proportion and prognostic impact of sources of bleeding in patients requiring re-exploration after adult cardiac surgery.

DESIGN

Systematic review of the literature and meta-analysis.

SETTING

Multistitutional study.

MEASUREMENTS AND MAIN RESULTS

A literature review was performed to identify studies published since 1990 evaluating the outcome after reoperation for bleeding or tamponade after adult cardiac surgery. Eighteen studies including 5,1497 patients fulfilled the selection criteria. Reoperation for bleeding/tamponade was performed in 2,455 patients (4.6%; 95% confidence interval [CI] 3.9%-5.2%, I² 92%). These had a significantly higher risk of in-hospital/30-day mortality compared with patients not reoperated for bleeding (pooled rates: 9.3% v 2.3%; risk ratio 3.30; 95% CI 2.52-4.32; I² 47%; 8 studies; 25,463 patients). Surgical sites of bleeding were identified in 65.7% of cases (95% CI 58.3%-73.2%; I² 94%), cardiac site bleeding in 40.9% of cases (95% CI 29.7%-52.0%; I² 94%), and mediastinal/sternum site bleeding in 27.0% of cases (95% CI 16.8%-37.3%; I² 94%). The main sites of bleeding were the body of the graft (20.2%), the sternum (17.0%), vascular sutures (12.5%), the internal mammary artery harvest site (13.0%), and anastomoses (9.9%). In metaregression, surgical site bleeding was associated with a lower risk of in-hospital/30-day mortality compared with diffuse bleeding (p = 0.003).

CONCLUSIONS

Surgical site bleeding is identified in two-thirds of patients undergoing re-exploration after adult cardiac surgery. Meticulous surgical technique and systematic intraoperative checking of potential surgical sites of bleeding at the time of the original cardiac surgery may reduce the risk of such a severe complication.