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

Heparin Management for Cardiopulmonary Bypass in Cardiac Surgery: A Prospective, Comparative and Randomized Study Evaluating a Dosage Based on the Ideal Body Weight 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.

Obese patients, randomized to receive an initial IV bolus of Heparin, before beginning of the cardiopulmonary bypass, at the dosage of 340 UI/kg based on ideal body weight of the obese patients. The objective is to obtain an ACT target ≥ 400 s before the beginning of CPB. If necessary, additional boluses of heparin are administered at the dose of 100 UI/kg based on ideal body weight, to maintain this target during the CPB.

Obese patients, randomized to receive an initial IV bolus of Heparin, before beginning of the cardiopulmonary bypass, at the usual dosage of 300 UI/kg based on total body weight of the obese patients. The objective is to obtain an ACT target ≥ 400 s before the beginning of CPB. If necessary, additional boluses of heparin are administered at the dose of 100 UI/kg based on total body weight, to maintain this target during the CPB.

Inclusion criteria: Obese patients (BMI ≥ 30 kg/m²) Planned cardiac surgery under cardiopulmonary bypass Coronary-artery bypass graft, or valve surgery) Age ≥ 18 yo Exclusion criteria: Allergy to heparin Emergency surgical intervention Redo surgery Heart transplantation Surgery for circulatory assistance Pre-operative heparin use

Vienne M, Haas E, Wipf T, Grunebaum L, Levy F, Sattler L, Hoang Minh T, Severac F, Tacquard C, Collange O, Mertes PM, Steib A. Adjusted calculation model of heparin management during cardiopulmonary bypass in obese patients: A randomised controlled trial. Eur J Anaesthesiol. 2018 Aug;35(8):613-620. doi: 10.1097/EJA.0000000000000784.