Association Between Platelet Count and Postoperative Blood Loss in Patients Undergoing Cardiac Surgery With Cardiopulmonary Bypass and Fresh Frozen Plasma Administration Guided by Thromboelastometry

Background: Coagulopathy after cardiopulmonary bypass (CPB) is caused by multiple factors, including reduced coagulation factors and a low platelet count. Methods and Results: In this study, we undertook a post hoc analysis to identify factors associated with increased postoperative blood loss in 97 patients undergoing cardiac surgery with CPB, with fresh frozen plasma administered according to a ROTEM-guided algorithm. We identified 24 patients for the top quartile of postoperative blood loss, >528 mL and defined as having excessive blood loss. Using Spearman's rank correlation test and multivariable linear regression, we reanalyzed the participants' demographic, surgical and anesthetic variables, laboratory test results, blood loss, and transfusion data. Univariate analysis indicated that patients who experienced higher postoperative blood loss received a significantly higher heparin dose, had a higher requirement for fresh frozen plasma transfusion during surgery, and had a significantly lower hematocrit and platelet count at the end of surgery compared with patients without excessive blood loss. Multivariate analysis showed that platelet count at the end of surgery (odds ratio 0.780, 95% confidence interval 0.629-0.967; P=0.024) was an independent factor for excessive blood loss. Conclusions: Low platelet count at the end of surgery was associated with excessive postoperative bleeding during cardiac surgery with CPB.