Efficacy of Dexmedetomidine for Prevention of Postspinal Anaesthesia Shivering in Orthopaedic Surgeries: A Double-blinded Randomised Controlled Study

Introduction: Post-spinal Anaesthesia Shivering (PSAS) refers to involuntary, repetitive skeletal muscle contractions triggered by a fall in core body temperature that generate heat but can cause significant discomfort, increase intracranial and intraocular pressures and raise oxygen demand with potential clinical consequences. Aim: To assess the efficacy of two intravenous (i.v.) doses of dexmedetomidine, administered prior to spinal anaesthesia, in preventing PSAS in patients undergoing lower limb orthopaedic procedures. Materials and Methods: This double-blinded, randomised controlled study was conducted at Department of Anaesthesia, King George’s Medical University, Lucknow, Uttar Pradesh, India in collaboration with the Department of Orthopaedics, for a period of 12 months, from October 2022 to September 2023. A total of 75, American Society of Anaesthesiologists (ASA) physical status grade I/II patients were scheduled for elective lower limb orthopaedic surgeries after ethical approval. Participants were randomly assigned to three groups (n=25 each) via a computer-generated sequence: Group I received 100 mL of normal saline; Group II received dexmedetomidine 0.25 μg/kg diluted in 100 mL saline; and Group III received dexmedetomidine 0.5 μg/kg in 100 mL saline. Infusions were administered over 10 minutes. Blinding was maintained for both the administering and observing anaesthesiologists. Categorical data (gender, ASA grade, incidence of shivering, consumption of tramadol) was analysed using Chi-square tests and continuous data {age, height, weight, Body Mass Index (BMI), duration of surgery and spinal anaesthesia, onset of shivering after spinal anaesthesia, temperature, Ramsay sedation score, Heart Rate, (HR) Systolic Blood Pressure (SBP)} was analysed using Analysis of Variance (ANOVA) tests, with level of significance (p-value