High Dose Heparinization is Associated with Higher Bleeding and Thrombosis Rates in Pediatric Patients Following Cardiac Surgery

Abstract Objective To determine the association between unfractionated heparin (UFH) dose and the rate of post-operative bleeding and thrombosis events in pediatric cardiac patients. We tested the hypothesis that high dose UFH doses are associated with higher rates of bleeding and thrombosis. Methods This is a retrospective review of pediatric patients admitted to the cardiac intensive care unit (CICU) following cardiac surgery between November 2016 and December 2017. Peripheral venous thrombosis was excluded from analysis. Bleeding was defined as spontaneous bleeding remote from procedural manipulation. Postoperative UFH dosing strategy was categorized into three groups: no UFH, low dose ( 15 u/kg/h UFH). Statistical analysis was performed using multivariable logistic regression. Results We observed 966 consecutive patients (median age=1.37 years, IQR=0.27, 5.50) during their stay in the CICU. There were 94 patients (10%) with bleeding and 52 patients (5%) with thrombosis during follow-up. Patients receiving high dose UFH experienced significantly more bleeding (OR=2.35; 95% CI=1.45, 3.95) and thrombosis events (OR=3.65; 95% CI=1.81, 7.38) compared with patients receiving low dose UFH. The odds of bleeding (OR=0.81; 95% CI=0.45, 1.47) and thrombosis (OR=0.59; 95% CI=0.26, 1.35) were similar in the low dose UFH and no UFH groups. Conclusion Bleeding remote from immediate post-surgical bleeding occurs uncommonly in pediatric patients following cardiac surgery. Anticoagulation with high dose UFH is associated with higher bleeding rates as well as higher thrombosis rates. Indications for high dose UFH should be carefully considered to reduce the rate of bleeding in this population.