Kaolin-activated thromboelastography and standard coagulation assays in cyanotic and acyanotic infants undergoing complex cardiac surgery: A prospective cohort study

Background and Aims: Several studies report the use of thromboelatography (TEG) to monitor coagulation in pediatric cardiac surgery. The aim of this study was to compare baseline and intraoperative TEG, TEG-functional fibrinogen, and standard coagulation assays in children with cyanotic and acyanotic congenital heart disease (CHD) undergoing cardiac surgery. Methods: This is a prospective observational study of 63 children aged <24 months undergoing cardiac surgery with cardiopulmonary bypass (CPB). Exclusion criteria included preoperative anticoagulant therapy and hepatic failure. We collected blood at anesthesia induction (T1), at lowest temperature after CPB start (T2), and after heparin neutralization (T3). Coagulation was evaluated by TEG (reaction time [R]), k, alpha-angle, maximum amplitude (MA), MA-fibrinogen (MA-fib), and by standard coagulation assays (prothrombin time, activated partial thromboplastin time, fibrinogen level, platelet [PLT] count). Results: Sixty-three patients were enrolled (38 cyanotic and 25 acyanotic). Median age was 4 [IQR 2-6] months and median weight was 5 [IQR 3.7-6.5] kg. Most common surgeries were: ventricular septal defect repair (n = 13), Fallot correction (n = 11), and arterial switch operation (n = 10). Cyanotic and acyanotic children were well matched: R, k, MA, and MA-fib at T1, T2, and T3 were not significantly different between cyanotic and acyanotic children. At T2, significant correlations were showed between MA and PLT count (r = 0.4; P = 0.0008) and k and plasma fibrinogen level (r = -0.54; P < 0.0001). At T3, significant correlations were showed between MA and PLT count (r = 0.5; P < 0.0001), G and PLT count (r = 0.6; P < 0.0001), and MA-fib and plasma fibrinogen level (r = 0.5; P = 0.002). Conclusions: According to our findings, cyanosis does not affect TEG parameters in children with CHD. PLT count and plasma fibrinogen significantly correlated (are significantly associated) with MA and MA-fib respectively, suggesting that use of TEG after protamine administration may be prompted for improved hemostatic monitoring in the perioperative phase.