Heparin Based on Ideal Body Weight for Cardiopulmonary Bypass in Obese Patients

The optimal heparin regimen during cardiopulmonary bypass (CPB) has not been well established in obese patients. Results of a preview study show that the standard heparin management based on total body weight in obese patients during CPB resulted in excessive heparin level, which could lead to excessive postoperative bleeding. To avoid this overdosing, an initial heparin bolus based on ideal body weight in obese patients was proposed. The main objective of the study is to evaluate the effects of heparin injection, based on ideal body weight, on intraoperative plasma heparin levels and activated coagulation time (ACT) in a population of obese patients, compared to a group of obese patients undergoing CPB surgery with heparin management based of total body weight. The secondary objectives are to evaluate the relationship between heparin level and ACT in each group of patients and at different time points during CPB, and to compare the incidence of bleeding, intraoperative transfusions and complications in the two groups of patients.