Prophylaxis with oral clonidine prevents perioperative shivering in patients undergoing transurethral resection of prostate under subarachnoid blockade

BACKGROUND: We investigated the efficacy of oral clonidine 150 mg to prevent perioperative shivering in patients undergoing transurethral resection of prostate under subarachnoid block. Geriatric patients who undergo transurethral resection of prostate are prone to perioperative shivering during spinal anesthesia. Use of prophylactic oral clonidine, which is known to reduce shivering, could lead to decrease in the morbidity and mortality of such patients. MATERIALS AND METHODS: In this prospective double blinded placebo-controlled study, 80 patients scheduled for transurethral resection of prostate surgery under subarachnoid block were randomized into two groups. Group I (n=40) received oral clonidine 150 mg, while Group II (n=40) were given placebo tablet. After achieving subarachnoid block, the incidence, severity and duration of shivering was recorded and compared in both the groups. The body temperature (axillary, forehead and tympanic membrane), hemodynamic parameters and arterial saturation were recorded at regular intervals. RESULTS: Incidence of shivering was significantly less in patients who were given oral clonidine when compared with that of the placebo group (5 vs. 40% respectively; P value of < 0.01). Clonidine did not lead to any collateral clinically significant side effects. CONCLUSION: We conclude that as a prophylaxis oral clonidine 150 mg is effective in reducing the incidence, severity and duration of perioperative shivering in patients undergoing transurethral resection of prostate surgery under spinal anesthesia