Comparison between Dexmedetomidine, Ketamine and Tramadol for Prevention of Perioperative Shivering under Spinal Anaesthesia: A Randomised Clinical Trial

Abstract

Introduction: Perioperative shivering after spinal anaesthesia is a common complication. Ketamine and tramadol are routinely used to prevent perioperative spinal shivering. Ketamine has the side-effect of delirium while tramadol causes nausea and vomiting. Dexmedetomidine an alpha2 agonist is superior to tramadol and ketamine in view of better central vasoconstrictor tone regulation and less sympathetic activity. Aim: To compare the efficacy, effect on haemodynamics, and any adverse effects of tramadol, ketamine and dexmedetomidine when used prophylactically to prevent perioperative shivering after spinal anaesthesia. Materials and Methods: This, randomised, clinical study recruited adult patients aged 18 to 65 years, of American Society of Anaesthesiologists (ASA) I and II, of both genders undergoing surgery under spinal anaesthesia between February 2018 and August 2018. A total of 120 patients were assigned to four groups: T, D, K, and N, to receive Tramadol 0.5 mg/kg or Dexmedetomidine 0.5 μg/kg or Ketamine 0.25 mg/kg or normal saline 5 mL, respectively. Each study drug was diluted to 5 mL using normal saline and administered as a slow intravenous (iv) bolus injection five minutes before spinal anaesthesia. Patients received subarachnoid block in L3-4 or L4-5 space in sitting position with 0.5% hyperbaric bupivacaine 15 mg. Patients were monitored for shivering, (using a four-point scale), level of consciousness, heart rate, SpO2 , respiratory rate, non invasive blood pressure, nausea and vomiting, at intervals of every five minutes for the first 30 minutes and every 15 minutes for the remaining observation period. Results: Dexmedetomidine (n=0) offered lower incidence of shivering prevention after spinal anaesthesia than ketamine (n=2,6.6%), tramadol (n=10,33%) and normal saline groups (n=11,36.6%). Dexmedetomidine also provided the advantages of maintaining haemodynamics, respiratory rate, and consciousness, similar to ketamine or tramadol (p-value>0.05). Conclusion: Dexmedetomidine is superior to ketamine and tramadol for the prevention of shivering after spinal anaesthesia.