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ACE inhibitor premedication attenuates sympathetic responses during surgery
M Böttcher1, J K Behrens, E A Møller
1Institute of Pharmacology, University of Aarhus, Denmark.
British Journal of Anaesthesia
|June 1, 1994
Summary
Ramipril, an ACE inhibitor, reduced blood pressure and attenuated heart rate increases during abdominal hysterectomy. It also increased cardiac output and inhibited noradrenaline release, suggesting angiotensin II facilitates sympathetic nerve activity.
Area of Science:
- Cardiovascular physiology
- Pharmacology
- Anesthesiology
Background:
- Abdominal hysterectomy can induce significant cardiovascular and catecholamine stress.
- Understanding the impact of perioperative medications on these responses is crucial for patient management.
Purpose of the Study:
- To investigate the effects of ramipril (ACE inhibitor) and metoprolol (beta 1 blocker) on cardiovascular and catecholamine responses during abdominal hysterectomy.
- To explore the role of angiotensin II in modulating sympathetic nervous system activity in this surgical context.
Main Methods:
- A randomized, placebo-controlled study involving three groups of patients undergoing abdominal hysterectomy.
- Administration of ramipril, metoprolol, or placebo before surgery and anesthesia induction.
- Monitoring of cardiovascular parameters (diastolic pressure, heart rate, stroke volume, cardiac output) and plasma/urine catecholamine (noradrenaline) levels.
Main Results:
- Ramipril significantly reduced diastolic pressure and attenuated heart rate and arterial pressure surges post-incision.
- Ramipril group showed higher stroke volume and cardiac output during surgery.
- Metoprolol did not significantly alter stroke volume or cardiac output.
- ACE inhibition with ramipril led to attenuated noradrenaline release.
Conclusions:
- Angiotensin II appears to facilitate noradrenaline release from sympathetic nerves.
- ACE inhibition with ramipril effectively inhibits this angiotensin II-mediated noradrenaline release.
- Ramipril demonstrates beneficial cardiovascular effects during major abdominal surgery.