Preoperative fibrinogen level and postcardiac surgery morbidity and mortality rates.

Background: High preoperative fibrinogen levels are associated with reduced bleeding rates after cardiac surgery. Fibrinogen is directly involved in inflammatory processes and is a cardiovascular risk factors. Whether high fibrinogen levels before cardiac surgery are a risk factor for mortality or morbidity remains unclear. Aims: This study aimed to examine the association between preoperative fibrinogen levels and mortality and morbidity rates after cardiac surgery. Settings and Design: This is a single-center retrospective study. Material and Methods: Patients (n = 1628) were divided into high (HFGr) and normal (NFGr) fibrinogen level groups, based on the cutoff value of 3.3 g/L, derived from the receiver operating characteristic (ROC) curve analysis. The primary outcome was the 30-day mortality rate. The rates of postoperative complications, including postoperative bleeding and transfusion rates, were examined. Statistical Analysis: Between-group comparisons were performed with the Mann-Whitney U test and Chi-squared test, as suitable. Model discriminative power was examined with the area under the ROC curve. Results: The HFGr and NFGr included 1103 and 525 patients, respectively. Mortality rate was higher in the HFGr than in the NFGr (2.7% vs. 1.1%, P = 0.04). The 12-h bleeding volume (280 mL [195-400] vs. 305 mL [225-435], P = 0.0003) and 24-h bleeding volume values (400 mL [300-550] vs. 450 mL [340-620], P < 0.0001) were lower in the HFGr than in the NFGr. However, the rate of red blood cell transfusion during hospitalization was higher in the HFGr than in the NFGr (21.7% vs. 5.9%, P = 0.0103). Major complications were more frequent in the HFGr than in the NFGr. Conclusion: High fibrinogen levels were associated with reduced postoperative bleeding volume and increased mortality and morbidity rates.

Heparin Reversal After Cardiopulmonary Bypass: Are Point-of-Care Coagulation Tests Interchangeable?

OBJECTIVE: Protamine is used to neutralize heparin after patient separation from cardiopulmonary bypass (CPB). Different bedside tests are used to monitor the adequacy of heparin neutralization. For this study, the interchangeability of the activated coagulation time (ACT) and thromboelastometry (ROTEM; Tem Innovations GmbH, Basel, Switzerland) clotting time (CT) ratios in children undergoing cardiac surgery was assessed. DESIGN: Single-center, retrospective, cohort study between September 2010 and January 2012. SETTING: University children's hospital. PARTICIPANTS: The study comprised children 0 to 16 years old undergoing elective cardiac surgery with CPB. Exclusion criteria were preoperative coagulopathy, Jehovah's witnesses, and children in a moribund condition (American Society of Anesthesiologists score 5). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: After heparin neutralization with protamine, the ratio between ACT, with and without heparinase, and the CT measured with INTEM/HEPTEM (intrinsic test activated with ellagic acid was performed without heparinase [INTEM] and with heparinase [HEPTEM]) using tests of ROTEM were calculated. Agreement was evaluated using Cohen's kappa statistics, Passing-Bablok regression, and Bland-Altman analysis. Among the 173 patients included for analysis, agreement between both tests showed a Cohen's kappa statistic of 0.06 (95% CI: -0.02 to 0.14; p = 0.22). Bland-Altman analysis showed a bias of 0.01, with a standard deviation of 0.13, and limits of agreement between -0.24 and 0.26. Passing-Bablok regression showed a systematic difference of 0.40 (95% CI: 0.16-0.59) and a proportional difference of 0.61 (95% CI: 0.42-0.86). The residual standard deviation was 0.11 (95% CI: -0.22 to 0.22), and the test for linearity showed p = 0.10. CONCLUSION: ACT, with or without heparinase, and the INTEM/HEPTEM CT ratios are not interchangeable to evaluate heparin reversal after pediatric patient separation from CPB. Therefore, the results of these tests should be corroborated with the absence/presence of bleeding and integrated into center-specific treatment algorithms.

Plasma fibrinogen concentration is correlated with postoperative blood loss in children undergoing cardiac surgery. A retrospective review.

BACKGROUND: Fibrinogen supplementation is increasingly recommended with the use of rotational thromboelastometry (ROTEM). However, data regarding the paediatric population are sparse. OBJECTIVE: We aimed to assess the relationship between plasma fibrinogen concentration and postoperative blood loss in children undergoing cardiac surgery. DESIGN: Retrospective analysis. SETTING: Data prospectively recorded in our departmental database between September 2010 and January 2012. PATIENTS: Data from 156 children scheduled for congenital heart surgery with ROTEM performed at the end of cardiopulmonary bypass (CPB) were analysed. INTERVENTION: None. MAIN OUTCOME MEASURES: Abnormal bleeding was defined as blood loss that exceeded 10% of total blood volume within the first 6 postoperative hours. Logistic regression analyses were used to determine variables associated with bleeding. Correlation analyses and receiver operating characteristic (ROC) curves were designed to evaluate the relationship between blood loss and plasma fibrinogen concentration or ROTEM variables, if relevant. RESULTS: Thirty-six children were considered as 'bleeders' and 120 as 'nonbleeders'. Univariate and multivariate logistic regression analysis revealed time for wound closure, clot formation time, maximal clot firmness (MCF) and plasma fibrinogen concentration as variables independently associated with postoperative bleeding. MCF was best correlated with plasma fibrinogen concentration. ROC curves for blood loss versus fibrinogen concentration and MCF showed that a plasma fibrinogen concentration of 1.5 g l and a MCF value 3 mm or less could be used to predict blood loss. CONCLUSION: Post-CPB plasma fibrinogen concentration significantly influences blood loss in children undergoing cardiac surgery. A fibrinogen concentration of at least 1.5 g l or a MCF of at least 3 mm should accurately predict excessive blood loss in cardiac surgery children. Further prospective trials are needed to assess the effect of fibrinogen supplementation on postoperative blood loss in this population.