Propranolol and ventricular arrhythmias with halothane

Abstract

The successful treatment of ventricular arrhythmias occurring during anasthesia was reported by Payne et al. 1 and Johnstone2 who used pronethalol, a B-adrenergic blocking drug.The disadvantages of pronethalol, namely the production of lightheadedness, inco-ordination leading to nausea and vomiting and a carcinogenic effect in mice, led to the investigation of other similar compounds, Black et al. 3 One of these, Compound ICI 45,520, (now referred to as propranolol or by the trade name 'Inderal') was found to have a therapeutic ratio about ten times that of pronethalol and was free from carcinogenic effects in mice.The following investigation was undertaken to see whether or not propranolol was effective in the treatment of ventricular arrhythmias occurring during halothane anzsthesia. METHODThe ECG was monitored during halothane anzsthesia on a number of patients admitted to hospital for a variety of elective operations. These included dental, ENT, orthopaedic and neurosurgical procedures.In all cases anasthesia was induced with thiopentone 200-500mg. If endotracheal intubation was necessary, it was performed with the aid of suxamethonium 30-75mg given after the thiopentone. Anasthesia was maintained with halothane using nitrous oxide 75 % and oxygen 25% as the carrier gases. If relaxation was required, tubocurarine was used, and respiration controlled using a circle absorption system. Halothane was vaporised from either a Fluotec vaporiser or a calibrated Boyle's bottle. A Fluotec, outside the circuit, was used with the circle absorption system. 269

Beta-Adrenergic Blockade and Anaesthesia with Reference to Interactions with Anaesthetic Drugs and Techniques

“…Intravenous propranolol has been widely employed in the control of ventricular arrhythmias during anaesthesia. 80,81,82,83,84 Practolol has proved equally effective in this respect. 85,86,39 Hypertensive patients subjected to laryngoscopy prior to endotracheal intubation showed alarming elevations in blood pressure often accompanied by ventricular ectopic beats and unmistakable ECG evidence of severe myocardial ischaemia.…”

The Effects of Some Anaesthetics and Ancillary Agents on Adrenoceptive Receptors

“…In an earlier section it was pointed out that all important cardiac, sympathetic effects were mediated by @-receptors. Hence, one can predict that @-receptor antagonists will either prevent or abolish many arrhythmias occurring during anaesthesia and this has been found to be SO in several species, including man, dog, cat and the horse (Fukushima eta/., 1968;Hellewell and Potts, 1965;Johnstone, 1966aJohnstone, . 1966bJohnstone, , 1970Lees and Tavernor, 1970;Pontinen eta/., 1965;Sharma, 1967).…”

Reflections on Beta-Adrenergic Blockade in Anaesthetics

“…It causes a slight prolongation of the atrioventricular conduction time, but unlike quinidine and procainamide, has no effect on intraventricular conduction (Berkowitz et al, 1969). It has been used successfully in the treatment of cardiac arrhythmias in anaesthetized patients (Hellewell and Potts, 1965;Johnstone, 1966;Bird et al, 1969). The effective dose in adults ranges between 0.5 and 10.0 mg according to the intensity of the adrenergic stimulus to be controlled.…”