Control of Shivering with Prophylactic Ketamine During Subarachnoid Block: A Placebo-Controlled Randomised Double- Blind Study

Introduction: Shivering is a common and challenging side effect of anaesthesia and may result in different degrees of perioperative hypothermia. Hence, the aim of the study was to compare the efficacy of ketamine to prevent shivering during subarachnoid block inpatient undergoing elective surgery. Material and Methods: We conducted a prospective randomized, double-blind placebo-controlled trial with total of 90 ASA I and II patients of either sex between the ages of 18 – 60 years undergoing elective infraumbilical surgery under subarachnoid blocks. Random allocation of patients was done into Group1: ketamine at dose of 0.5 mg /kg (n=30), Group2: ketamine at dose of 0.25 mg /kg (n=30), Group3: saline (n=30). Results: The study groups were comparable at the baseline. After spinal anaesthesia and concomitant administration of the study drug, shivering was observed only in 10% of patient with score 1 in Group 1 and Group 2. Whereas in placebo group 50% patients suffered different degrees of shivering and required treatment (p<0.05). After drug injection % of patient had higher sedation score (3 or 2) which was significantly higher in Group 1 (3%) than Groups 2 and 3 (0%) (P=0.002). Only 3.3% patients of group1 experienced hallucination and rest of the patients in any group had no hallucination (P value= 0.045) Conclusion: Ketamine at a dose of 0.5 mg /kg had similar effects as that of ketamine at dose of 0.25 mg /kg when compared to placebo group. However, ketamine at dose of 0.5 mg /kg caused higher effects of sedation and hallucination. KeywordsShivering, Ketamine, Subarachnoid Blocks, Elective Infra-Umbilical Surgery