Inhibition of metabolic responses to surgery with β-adrenergic blockade

Glucose, lactate, non-esterified fatty acid and insulin levels in plasma were measured in two groups of 12 patients undergoing gastrectomy under general anaesthesia. Propranolol in a dose of 0.3 mg/kg body weight was intraoperatively infused in one of the two groups. Surgery under general anaesthesia elicited a significant rise in blood glucose, lactate and NEFA concentrations. These metabolic responses were significantly inhibited by intraoperative infusion of propranolol without producing any undesirable side effect. Plasma insulin levels showed a slight decrease during the operation and no significant difference was noted between the two groups. The results suggest that beta-adrenergic activity is playing a major role in these metabolic responses, promoting the mobilization of substrates. Possible benefits of inhibiting beta-adrenergic activation in surgical stress are discussed.