USE OF KETAMINE PLUS MIDAZOLAM VERSUS KETAMINE ALONE IN PREVENTION OF SHIVERING DURING SPINAL ANAESTHESIA: A RANDOMIZED CONTROLLED TRIAL

OBJECTIVE: To compare the efficacy of combination of ketamine plus midazolam with that of ketamine alone in the prevention of shivering during spinal anaesthesia METHODOLOGY. This double blinded randomized controlled clinical trial was carried out at institute of kidney diseases Hayatabad, Peshawar from 16 October 2012 to 15 April 2013. Two hundred patients,classified by American Society of Anesthesiologists (ASA) physical status category I-II, listed for urologic surgery were randomized by card method in two groups of 100 patients each. Subarachnoid (spinal)anaesthesia was performed in all patients with bupivacaine 15 mg. The patients were randomly allocated to receive ketamine 0.25 mg/kg plus midazolam 37.5 μg/kg (Group A) or ketamine 0.5 mg/kg (Group B).During surgery, a shivering score was recorded at 5 min intervals. If 15 minutes after spinal anaesthesia and concomitant administration of a prophylactic dose of one of the study drugs, grade 3 or 4 shivering was noted, the prophylaxis was regarded as ineffective and pethidine 25 mg intravenously was administered.RESULTS: After 15 min, the incidences of shivering in groups A and B were 4% and 25% (P= 0.0001). Mean shivering score was 0.05±0.26112 and 0.43±0.87911 in group A and group B respectively.The number of patients with a shivering score of ≥3 was significantly higher in group B compared with groups A (4 vs. 0, respectively,P=0.0434).CONCLUSION: Prophylactic use of ketamine (0.25 mg/kg) plus midazolam (37.5 μg/kg) intravenously was more effective than ketamine (0.5 mg/kg) intravenous alone in preventing shivering developed during spinal anaesthesia.