[Preoperative administration of angiotensin-converting enzyme inhibitors]

The discussion about perioperative withdrawal or continuation of angiotensin-converting enzyme inhibitors (ACEI) remains controversial. Should it be continued to avoid peaks in blood pressure and heart rate during anesthesia? Or should it be discontinued the day before to avoid clinically relevant hypotonia? What is the greater risk? Since there are only a few studies dealing with this question, we compared the cardio-circulatory reaction during anesthesia after withdrawal and with continuation of ACEI therapy.

A total of 100 hypertonic patients chronically treated with ACEIs were included in this prospective, randomized, double blind study. The last ACEI medication was given with the premedication in the morning (premed) or on the day before (withdrawal). Blood pressure and heart rate during induction and termination of anesthesia were compared between both groups. A threshold value for vasopressor therapy was determined to be a mean arterial pressure of 60 mmHg.

In the premed group Akrinor was necessary significantly more often and in higher dosages. Nevertheless, following induction the blood pressure and heart rates were significantly lower compared to the withdrawal group. The highest blood pressure and heart rate during induction and termination of anesthesia did not differ between the groups.

The continuation of ACEI therapy in the morning is not associated with a better control of blood pressure and heart rate but causes a more pronounced hypotension which forced a therapy more often. Patients chronically treated with ACEI should receive the ACEI the last time on the day before the operation and not with the premedication in the morning.