Comparison of prophylactic administration of Ondansetron and Dexmedetomidine for the prevention of post-spinal anaesthesia shivering in lower abdominal surgeries : A randomized controlled trial

Post Spinal Anaesthesia Shivering (PSAS) is known to be a frequent complication and has reported incidence of 40-70%. Shivering is defined as the involuntary and oscillatory muscular activities that increase the metabolic rate by two to three folds to maintain the core temperature, with the increment of heat production. The study will be a Randomized controlled double blinded study to compare the efficacy of prophylactic Ondansetron and Dexmedetomidine in the prevention of post spinal shivering in patients undergoing elective lower abdominal surgeries under spinal anaesthesia.

A total number of 96 patients aged 18-60 years of either sex, ASA physical grade I and II who will be undergoing elective lower abdominal surgeries shall be enrolled in the study. The patients will be divided into three groups of 32 each. The study drug will be prepared in a 5 ml syringe by an anaesthesiologist not directly involved in the study to keep the study blinded. Group A will receive Normal saline, Group B will receive 0.1 mg/kg of intravenous Ondansetron and Group C will receive 1 mcg/kg of intravenous Dexmedetomidine. 0.5% of Inj. hyperbaric Bupivacaine will be used for spinal anaesthesia. The operating room temperature will be maintained at an ambient temperature of around 24 degree Celsius to 26 degree Celsius. Vital parameters like temperature, blood pressure, heart rate, SpO2 will be recorded preoperatively and intraoperatively. Time of onset of shivering along with its grade and the disappearance of shivering will be recorded. In case of failure to control shivering by study drugs 0.5 mg/kg of Inj. Tramadol will be used as rescue therapy.

The data collected will be analyzed and interpreted by appropriate statistical method. Quantitative data will be analyzed using Students t test and qualitative data will be analyzed using Chi square test. P value less than 0.05 will be taken as significant.