Efficacy of Intravenous Midazolam & Ketamine Combination in the Treatment of Shivering after Spinal Anaesthesia – A Comparative Study with Intravenous Midazolam & Pethidine Alone

Abstract

Background: Post spinal shivering is very distressing for patients and may induce a variety ofcomplications.1 The principal reasons for hypothermia are - it leads to an internal redistribution of heatfrom the core to the peripheral compartment, loss of thermoregulatory vasoconstriction below the level ofthe spinal block and altered thermoregulation due to vasodilation and shivering thresholds3,4,5,21. Presentstudy demonstrated that the combination of midazolam and ketamine treats the hypothermia that isoften less effective with midazolam or pethidine alone.

Objectives: To assess the effectiveness of midazolam-ketamine combination over midazolam & pethidinealone in post spinal shivering.

Methods: This hospital based randomized double blind controlled study. One hundred fifty patients,classified by (ASA) physical status category I-II, were randomized by card method in three groups of 50patients each. Subarachnoid (spinal) anaesthesia was performed . The patients were randomly allocatedto receive 0.025 mg/kg midazolam + 0.25 mg/kg Ketamine (Group A), 0.035 mg/kg i/v midazolam(Group B), and 0.5 mg/kg i/v pethidine (Group C). After development of shivering, it graded and recorded.1st dose of drugs given as coded in syringe A,B,C. If the grade 3 or 4 after 15 min from the administrationof the study drug, the prophylaxis was regarded as ineffective and pethidine 25 mg intravenously wasadministered.

Result: Patients characteristics in respect of age, residence, others socio-demographic characteristics,ASA status and type of surgery were similar between the groups. Heart rate and mean arterial bloodpressure values were less and close to base levels without requirement of any other rescue medicationand remained stabilized throughout the intraoperative period in midazolam & ketamine (Group A)patient.

Conclusion: The most effective measures for prevention and treatment of post-spinal shivering are forcedair warming, fluid warming with combating pharmacological agents e.g. midazolam, ketamine, morphine,fentanyl, and pethidine etc. In our study midazolam plus metamine is more effective than other hadproven.

JBSA 2017; 30(2): 75-82