Preoperative angiotensin-converting enzyme inhibition can cause severe post CPB vasodilation--current UK opinion

Preoperative use of angiotensin-converting enzyme inhibitors in cardiac surgery patients is thought to cause extreme vasodilatation in post cardiopulmonary bypass period. Opinions are divided as to whether it is beneficial or not to stop it prior to operation. A national survey in the UK was carried out on this issue. Questionnaires were sent to 167 currently practicing UK cardiac surgeons, out of which 105 (62%) replied back. Their responses were analyzed. Among the surgeons who replied to the questionnaires, the majority (63%) were of the opinion that the use of angiotensin-converting enzyme inhibitors leads to vasodilatation resulting in increased usage of fluids, inotropes and vasoconstrictors. However, there was no agreement on the issue of stopping it prior to surgery. Forty one (39%) felt it was beneficial to stop the angiotensin-converting enzyme inhibitors prior to surgery whereas 40 (38%) of them thought it was harmful to stop it. Twenty one (20%) were of the opinion that it made no difference. 39% of respondents practiced stopping the drug prior to planned operation. This national survey revealed differences in management of patients on angiotensin-converting enzyme inhibitors undergoing cardiac surgery. Recommendations from available literature are equally varied, highlighting the need for multicenter randomized trials to address this clinical problem.