Different drugs for prevention of post subarachnoid block shivering. Randomized, controlled, double blind

Background: Shivering is one of the most stressful complications for both the surgeon and the anesthesiologist during neuraxial anesthesia. The aim of this prospective randomized double blinded study was to evaluate the effectiveness of preoperative administration of granisetron, dexmedetomidine, and tramadol in prevention of shivering in patients undergoing elective operations with subarachnoid anesthesia. Methods: 320 patients ASA I or II aged between 18 and 65 years scheduled for elective operations under subarachnoid block were included in the study. They were divided randomly into four equal groups, and 10 min before performance of subarachnoid block, patients in group G (n = 80) received 40 μg/kg intravenous infusion of granisetron in 100 ml of normal saline, patients in group D (n = 80) received 0.5 μg/kg intravenous infusion of dexmedetomidine in 100 ml of normal saline, patients in group T (n = 80) received 1 mg/kg intravenous infusion of tramadol in 100 ml of normal saline, and patients in group C (n = 80) received 100 ml of normal saline as control. The following parameters were assessed: heart rate, mean arterial blood pressure, SPo2 and core temperature at the following times: 0 time, 5 min,10 min, 15 min, then every 15 min till end of the surgery. The incidence and intensity of shivering during the operation were recorded. Results: Study found statistically significant decrease in the incidence of shivering in group G, group D, and group T in comparison with group C without statistical significant difference between group G, group D, and group T. There was no statistical significant difference in the core temperature between the four groups. Conclusion: Preoperative administration of granisetron, dexmedetomidine, and tramadol was effective in decreasing the incidence and intensity of post subarachnoid shivering without increasing the incidence of the side effects