Setting Heart-Lung Machine Flow by Ideal Body Weight in Obese Adults Having Heart Surgery
Tests pump flow based on ideal body weight in obese adults having heart surgery.
Plain-language title generated from the registry record
Registry title: Optimized Cardiopulmonary Bypass Flow Strategy Based on Ideal Body Weight in Obese Patients Undergoing Cardiac Surgery
Key facts
- Where
- Amiens, FranceSee the site
Where in France
- Chu Amiens PicardieAmiens, FranceTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Centre Hospitalier Universitaire, Amiens
- Trial code
- NCT07917494
- Record updated
- 4 November 2026
- Original description
Cardiopulmonary bypass (CPB) pump flow is typically calculated according to body surface area (BSA) derived from actual body weight and temperature, following the 2024 European guidelines recommending an indexed flow of 2.4 L/min/m². However, in obese patients, using actual weight leads to a high BSA and thus elevated pump flow, increasing technical challenges such as the need for larger cannulas, higher circulating blood volume, and elevated pump speeds. These adjustments may increase risks of hemodilution, transfusion, and hemolysis. Given that lean body mass in obese patients is similar to that of non-obese patients of the same height-and that aerobic metabolism depends on lean mass-adjusting CPB flow based on ideal body weight rather than actual weight could reduce transfusions and associated complications. Several observational studies support the concept of using ideal body weight for CPB flow calculation in obese patients. Despite this, no randomized controlled trial has yet addressed the clinical impact of this approach. Given the increasing prevalence of obesity and the practical challenges it poses during cardiac surgery, a controlled clinical trial is warranted.Read full original descriptionShow less
Optimized Cardiopulmonary Bypass Flow Strategy Based on Ideal Body Weight in Obese Patients Undergoing Cardiac Surgery
Cardiopulmonary bypass (CPB) pump flow is typically calculated according to body surface area (BSA) derived from actual body weight and temperature, following the 2024 European guidelines recommending an indexed flow of 2.4 L/min/m². However, in obese patients, using actual weight leads to a high BSA and thus elevated pump flow, increasing technical challenges such as the need for larger cannulas, higher circulating blood volume, and elevated pump speeds. These adjustments may increase risks of hemodilution, transfusion, and hemolysis. Given that lean body mass in obese patients is similar to that of non-obese patients of the same height-and that aerobic metabolism depends on lean mass-adjusting CPB flow based on ideal body weight rather than actual weight could reduce transfusions and associated complications. Several observational studies support the concept of using ideal body weight for CPB flow calculation in obese patients. Despite this, no randomized controlled trial has yet addressed the clinical impact of this approach. Given the increasing prevalence of obesity and the practical challenges it poses during cardiac surgery, a controlled clinical trial is warranted.
The investigators hypothesize that adjusting the cardiopulmonary bypass (CPB) flow according to the ideal body weight rather than the actual body weight in obese patients could reduce the need for blood transfusions and limit the associated complications.
Inclusion: Patients aged over 18 years; Patients with obesity (BMI > 30 kg/m²); Scheduled cardiac surgery under cardiopulmonary bypass (CPB):; Coronary artery bypass grafting (CABG); Aortic valve replacement; Mitral valve repair or replacement; Surgery on the aortic root (aortic tube, Bentall procedure, Tirone David, or others); Combined surgery; Affiliation to a social security scheme; Written informed consent.
Exclusion: Surgery on the aortic arch; Emergency surgery; Off-pump cardiac surgery; Heart transplantation or mechanical circulatory support surgery; Coexisting disease with a high probability of death within 6 months; Advanced chronic kidney disease (renal clearance < 30 ml/min); Preoperative anemia (hemoglobin < 10 g/dL); Minors; BMI < 30 kg/m²; Planned perioperative hypothermia < 32ºC; Infectious endocarditis; Participation in another clinical trial within the past 30 days; Pregnant, parturient, or breastfeeding women; Patients under guardianship, curatorship, or deprived of civil rights; Body surface area (actual body weight) > 2.5 m².