Comparison between dexmedetomidine, ketamine, or dexmedetomidine–ketamine combination for control of shivering during spinal anesthesia

Background Regional anesthesia, like general anesthesia, influences the thermoregulatory process. In this study, we aimed to compare the efficacy, hemodynamic stability, and adverse effects of dexmedetomidine (DEX), ketamine, and the combination between them when used for control of shivering that occurs during spinal anesthesia. Patients and methods In this double‑blind study, 90 male and female patients of ASA status I and II with age 18 up to 60 years old scheduled to undergo elective lower extraperitoneal abdominal and lower limb surgery using spinal anesthesia were included. This study was done from January 2017 to July 2017. Results There was no significant difference in shivering control among the three groups, which was complete (when post‑treatment shivering score declined to score 0) in 28 (93.3%) patients in DEX group, 27 (90%) patients in ketamine group, and 25 (83.33%) patients in combination group (P = 0.321), whereas incomplete (when the scores decreased but did not abolish the shivering completely) in two (6.67%) patients in DEX group, three (10%) patients in ketamine group, and five (16.67%) patients in combination group (P = 0.234). Conclusion We concluded that intravenous DEX 0.4 mcg/kg, intravenous ketamine 0.3 mg/kg, or combination between DEX 0.25 mcg/kg and ketamine 0.25 mg/kg significantly controlled the shivering that occurred during spinal anesthesia. However, DEX is superior to ketamine and the combination in prevention of shivering.