Prophylactic Use of Intravenous Clonidine Compared to Tramadol in Prevention of Intraoperative Shivering under Regional Anesthesia

OBJECTIVES This study aimed to evaluate the relative efficacy of prophylactic intravenous (IV) clonidine and tramadol for control of intraoperative shivering following spinal anesthesia. MATERIALS AND METHODS After institutional ethical clearance, 142 patients were chosen from either gender, aged 20-60 years, physical status American Society of Anesthesiology Class I and II scheduled for elective infraumbilical surgery under spinal anesthesia. Patients were randomized into two groups: Group C (n = 71) received injection clonidine 50 μg) IV in 100 ml normal saline (NS) over 10 min and Group T (n = 71) received injection tramadol 50 mg IV. In 100 ml NS over 10 min after spinal anesthesia. RESULTS Incidence of shivering was not significant when compared between the two groups (P > 0.05). The axillary temperatures fell significantly in Group C from the baseline and remained at a significantly lower level up to 60 min after rescue drug was administered in patients who shivered. There was a similar fall in axillary temperature in Group T in patients having shivering, but the difference was not significant. When compared between the two groups among patients who shivered, the difference in fall of temperature was not significant. Side effects such as hypotension, bradycardia, and sedation were significantly more common in clonidine group, whereas nausea was significantly more common patients of tramadol group. CONCLUSION Prophylactic administration of both tramadol and clonidine is effective for controlling shivering under spinal anesthesia. However, tramadol is better because of higher response rate, less sedation, and lesser hemodynamic alterations.