The Effect of Intravenous Ketamine on Prevention of Hypotension During Spinal Anesthesia in Patients With Benign Prostatic Hyperplasia

Abstract

Objective: Hypotension is a common complication during spinal anesthesia. The elderly are at an increased risk of developing complications from hypotension due to reduced physiological reserves. Ketamine induces activation of the sympathetic nervous system, thus often increasing heart rate and blood pressure. The aim of our study was to determine protective effects of ketamine on hemodynamic changes under spinal anesthesia in the elderly patient. Material and Method: Sixty patients (ASAI-III) scheduled to undergo spinal anesthesia for transurethral resection were randomly allocated to receive either ketamine or placebo intravenously (i.v.) during the procedure. Immediately before spinal anesthesia, 500 ml of an isotonic NaCl solution was administered i.v. Patients received either placebo 2 cc NaCl solution i.v. before anesthesia or ketamine 1 mg/kg in 2 cc i.v. before spinal anesthesia. Results: In both groups, spinal anesthesia resulted in a reduction in Mean Arterial Pressure (MAP). MAP was lower in the placebo group than in the ketamine group at all times. There was a significant change in heart rate in placebo group compared to ketamine group (p<0.05). Conclusion: We concluded that ketamine 1 mg/kg i.v. given before spinal anesthesia resulted in greater hemodynamic stability in elderly patients undergoing transurethral resection compared with placebo.