Prophylactic i.m. ephedrine in bupivacaine spinal anaesthesia

Abstract

In a double-blind, placebo-controlled, randomized study, we have investigated the efficacy of i.m. ephedrine in 98 elderly patients undergoing hip arthroplasty under spinal anaesthesia with plain bupivacaine. Fifty patients received ephedrine 0.6 mg kg-1 body weight, deep in the paravertebral muscles immediately after injection of bupivacaine, and 48 received an equal volume of saline. Patients in both groups were given the same volumes of fluid before anaesthesia. Systolic arterial pressure during the first 60 min after anaesthesia remained significantly more stable in the ephedrine-treated group, and there was also a significantly smaller number of patients in this group who had decreases in pressure of more than 30% of pre-block levels, and fewer required rescue i.v, ephedrine. An increase in heart rate or systolic pressure of ≥ 20% from baseline was found in two patients in the ephedrine group and in one patient in the placebo group. We conclude that ephedrine 0.6 mg kg-1 body weight administered in the paravertebral muscles immediately after plain bupivacaine spinal anaesthesia is a simple and effective means of reducing the incidence of hypotensive episodes in the elderly patient.