Safety and Efficacy of Dexmedetomidine in Treating Post Spinal Anesthesia Shivering: A Randomized Clinically Controlled Dose-Finding Trial.

BACKGROUND The optimum dose of dexmedetomidine for shivering control with the least hemodynamic derangements is still under research. OBJECTIVE To compare the efficacy, hemodynamic and side effects of dexmedetomidine in 3 different doses with those of meperidine for the treatment of shivering in patients undergoing spinal anesthesia for minor elective lower abdominal surgery. STUDY DESIGN Prospective double-blind randomized clinically controlled study. SETTING University hospital. METHODS One hundred twenty patients who developed shivering under spinal anesthesia.On shivering, patients were randomly allocated to receive an intravenous 2 mL bolus dose of meperidine 0.4 mg/kg (meperidine group, n = 30), dexmedetomidine 0.5 µg/kg (DEX I group, n = 30), 0.3 µg/kg (DEX II group, n = 30), or 0.2µg/kg (DEX III group, n = 30). Control of shivering, time taken for cessation of shivering, response rate, recurrence, hemodynamic changes, sedation score, tympanic temperature, and side effects were noted and compared between groups. RESULTS The groups were comparable regarding demographic profile, tympanic temperature decline, and shivering onset time (P > 0.05). Lower shivering cessation time (P < 0.001) and higher response rate (P < 0.01) were observed in DEX I and II groups compared with DEX III and meperidine groups, with a nonsignificant difference between DEX I and II groups. Recurrence of shivering activity was higher in DEX III group (36.7%, P < 0.01) compared with DEX I (10%), DEX II (6.7%) and meperidine (16.7%) groups. Lower heart rates, systolic and diastolic blood pressure mean values were recorded in DEX I group (P < 0.05). Nine patients (30%) in DEX I group were in levels 3 - 5 of sedation (P < 0.02) compared with 5 (16.66%), 2 (6.66%), and 4 (13.3) patients in DEX II, DEX III, and meperidine groups, respectively. LIMITATIONS This study is limited by its small sample size. CONCLUSIONS Among the 3 doses investigated, dexmedetomidine 0.3µg/kg effectively treated shivering associated with spinal anesthesia with modest hemodynamic and sedation effects. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT02382432. KEY WORDS Dexmedetomidine, hypothermia, shivering, spinal anesthesia.