Effect of clonidine and dexmedetomidine premedication on perioperative oxygen consumption and haemodynamic state

• Published in: British Journal of Anaesthesia Vol. 78; no. 4; pp. 400 - 406
• Main Authors: Taittonen, M T, Kirvelä, O A, Aantaa, R, Kanto, J H
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 01.04.1997; Oxford University Press; Oxford Publishing Limited (England)
• Subjects: Adrenergic alpha-Agonists - pharmacology; Adult; Anesthesia, General; Biological and medical sciences; Cardiovascular system; Clonidine - pharmacology; Double-Blind Method; Female; Hemodynamics - drug effects; Humans; Imidazoles - pharmacology; Male; Medetomidine; Medical sciences; Middle Aged; Miscellaneous; Oxygen Consumption - drug effects; Pharmacology. Drug treatments; Premedication; Surgery, Plastic; Sympatholytics - pharmacology; Human; α2-Adrenergic receptor; Agonist; Dexmedetomidine; General anesthesia; Oxygen consumption; Clonidine; Hemodynamics; Catecholamine; Sympathetic nervous system; Premedication
• DOI: 10.1093/bja/78.4.400
• ISSN: 0007-0912

Premedication has been shown to affect both oxygen consumption and metabolic rate. We have compared the perioperative metabolic and haemodynamic effects of two alpha 2-agonists, clonidine and the more selective dexmedetomidine, in 30 ASA I patients undergoing plastic surgical procedures under general anaesthesia. Patients were premedicated with clonidine 4 micrograms kg-1 (n = 10), dexmedetomidine 2.5 micrograms kg-1 (n = 10) or saline (n = 10) i.m. The doses of clonidine and dexmedetomidine were intended to be equipotent. The maximum decrease in preoperative oxygen consumption was 8% and decreases in systolic and diastolic arterial pressures were 11% from baseline after clonidine and dexmedetomidine. During operation, the maximum reduction in heart rate was 18% in the clonidine and dexmedetomidine groups compared with the placebo group. After operation, the maximum decrease in systolic arterial pressure was 11%, diastolic arterial pressure 15% and oxygen consumption 17% in the clonidine and dexmedetomidine groups compared with placebo. In summary, both clonidine 4 micrograms kg-1 and dexmedetomidine 2.5 micrograms kg-1 decreased perioperative oxygen consumption effectively, with a similar haemodynamic profile.