Effectiveness of Ephedrine Used in Perioperative Management of Spinal Anaesthesia Induced Hypotension During Lower Limb Orthopaedic Surgery

Abstract

Background: Hypotension is the commonest adverse effect that is encountered after spinal anaesthesia. It is usually an exaggeration of the physiological effects of the spinal blockade. The sympathectomy that occurs after the spinal blockade is responsible for the hypotension and bradycardia which, if not adequately managed, leads to organ hypoperfusion; and if severe, to multiple organ failure and death. Objective: Our objective was to assess the effectiveness of ephedrine used prophylactically or interventionally in the perioperative management of spinal-induced hypotension among ASA I and ASA II patients undergoing elective lower limb orthopaedic surgery at The Kenyatta National Hospital. Methodology: This was a comparative observational study in which consenting ASA I and ASA II adult patients undergoing orthopaedic surgery under spinal anaesthesia were conveniently sampled. Data was collected by observing the perioperative ephedrine use by the anaesthetists and also the perioperative changes in blood pressure and heart rate and the management of spinal induced hypotension when it occurred. Results: Overall incidence of hypotension was 50%.The cumulative incidence of post spinal hypotension was lower in the prophylaxis group 46.2% as compared to the no prophylaxis group 53.8%. The requirement for rescue vasopressors was also higher in the no prophylaxis group32.1% as compared to the prophylaxis group 23.1%. These differences were however not statistically significant. Hypertension and tachycardia occurred in 3% and 9.2% of patients respectively who received prophylactic ephedrine. Conclusion: There was no statistically significant reduction in the incidence of post spinal hypotension or the requirement for rescue vasopressors following administration of prophylactic intramuscular ephedrine. Ephedrine is a safe drug and anaesthetists should continue to use either of the regimens safely.