Canadian Journal of Anesthesia, Vol 15, 42-55, Copyright © 1968 by Canadian Anesthesiologists' Society

Beta-Adrenergic Blocking Agents and Anaesthesia: A Review

¹ University of Florida College of Medicine, Gainesville, Florida

Beta-adrenergic receptor blockade may have extensive use in clinical medicine. Interactions between beta-adrenergic blocking drugs and anaesthetic agents may have life-threatening ramifications and sequelae. Physiological responses to anaesthetic agents which stimulate sympatho-adrenal activity may be altered markedly.

Beta-adrenergic blocking agents are contraindicated in patients with atrioventricular block and idioventricular rhythm, because all cardiac electrical activity may be abolished. Relative contraindications include asthma and other broncho-spastic states and conditions predisposing towards hypoglycaemia, e.g. insulin-treated diabetes mellitus.

Anaesthetized patients subjected to beta-adrenergic blockade will have decreased tolerance to any factor that increases cardiac work. Patients with hearts dependent upon sympathetic support for survival will not tolerate removal of that support, regardless of anaesthetic agent superimposed.

Without beta-adrenergic support, evidence of falling cardiac output will be manifested as hypotension and bradycardia. Central venous pressure will rise if the myocardium fails.