Correlations between global clotting function tests, duration of operation, and postoperative chest tube drainage in pediatric cardiac surgery

Abstract

Systemic coagulation disorders after cardiac surgery represent serious postoperative complications. There have been few reports, however, identifying preoperative coagulation tests that predict postoperative bleeding. The aim of the present study was to investigate the relationship between postoperative hemorrhage and coagulation parameters determined by global coagulation assays, to define potential predictive markers. Twenty-one pediatric patients were enrolled. Blood samples were collected before and 24 h after cardiac surgery. Laboratory investigations included platelet count, hematocrit, classical coagulation tests [prothrombin time, activated partial thromboplastin time, thrombin-antithrombin complex (TAT)], rotation thromboelastometry (ROTEM), and the thrombin generation test (TGT). The duration of the surgical procedure was recorded. Chest tube drainage was monitored for 24 h after operation as an index of postoperative hemorrhage. Comparisons between preoperative and postoperative results indicated that TAT increased significantly after operation, whereas ROTEM parameters did not show a hypercoagulable pattern. Preoperative endogenous thrombin potential (ETP) measured in the TGT and clot formation time (CFT) in the ROTEM correlated with chest tube drainage. The classical coagulation tests were not informative. Postoperatively, peak height and ETP in TGT, all ROTEM parameters, and duration of surgery were correlated with chest tube drainage. Duration of surgery was correlated with postoperative ROTEM parameters but not with TGT. Postoperative maximum clot firmness and AUC were correlated with platelet count decrease ratio. The preoperative CFT and ETP provide useful indices for predicting postoperative chest tube drainage volume. In addition, the duration of surgery also correlated with chest tube drainage and affected ROTEM parameters.