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

ABSTRACT

Introduction: Shivering is a common and challenging sideeffect of anaesthesia and may result in different degrees ofperioperative hypothermia. Hence, the aim of the study was tocompare the efficacy of ketamine to prevent shivering duringsubarachnoid block inpatient undergoing elective surgery.Material and Methods: We conducted a prospectiverandomized, double-blind placebo-controlled trial with totalof 90 ASA I and II patients of either sex between the agesof 18 – 60 years undergoing elective infra- umbilical surgeryunder subarachnoid blocks. Random allocation of patientswas done into Group1 ketamine at dose of 0.5 mg /kg (n=30),Group2 ketamine at dose of 0.25 mg /kg (n=30), Group3saline (n=30).Results: The study groups were comparable at the baseline.After spinal anaesthesia and concomitant administration ofthe study drug, shivering was observed only in 10% of patientwith score 1 in Group 1 and Group 2. Whereas in placebogroup 50% patients suffered different degrees of shivering andrequired treatment (p<0.05). After drug injection % of patienthad higher sedation score (3 or 2) which was significantlyhigher in Group 1 (3%) than Groups 2 and 3 (0%) (P=0.002).Only 3.3% patients of group1 experienced hallucination andrest of the patients in any group had no hallucination (P value=0.045)Conclusion: Ketamine at a dose of 0.5 mg /kg had similareffects as that of ketamine at dose of 0.25 mg /kg whencompared to placebo group. However, ketamine at dose of 0.5mg /kg caused higher effects of sedation and hallucination.