Anticoagulation Strategies in Pediatric Cardiopulmonary Bypass, Weight-Based vs. Concentration-Based Approaches

Pediatric patients undergoing cardiopulmonary bypass (CPB) require adequate anticoagulation to combat hemostatic activation. Heparin is used to bind and catalyze antithrombin III (ATIII) that works to inhibit clot formation. To dose heparin, a weight-based (WB) or patient-specific concentration-based (PSCB) method can be used. The WB protocol calculates the dose based on the patients' weight and uses an activated clotting time (ACT) test to ensure anticoagulation. The ACT has limitations during CPB especially for pediatric patients who have immature hemostatic systems. The PSCB method predicts the patients' response to heparin by projecting a heparin dose-response (HDR) curve. Some investigators have found benefit to using the PSCB method but further investigation into how well the HDR predicts the heparin response is needed. A literature review was conducted for studies that looked at heparin management strategies in pediatric CPB patients between 1992 and 2020. Articles that focused on pediatric physiology, heparin management strategies, and anticoagulation were included. Articles older than 1990 were excluded. The literature review highlights that utilizing the PSCB approach more adequately anticoagulated patients. The WB protocol was found to have several flaws due to its reliance on the ACT, especially in infants. The results show that further investigation is needed to understand why there is benefit to using the PSCB approach. Observing the association between the HDR curve and subsequent heparin concentrations could determine how accurately it predicts the patients' response to heparin and why there is benefit to using this method.