A Comparative Study on the Effects of Mirtazapine, Dexamethasone, And Tramadol for Prevention of Post-Spinal Anaesthesia Shivering in Gynaecological Surgeries in a Tertiary Care Hospital: A Randomized Controlled Trial

Abstract

Background: Post-spinal anaesthesia shivering (PSAS) is a frequent and distressing complication, impacting physiological stability and surgical outcomes. Effective prevention is critical to enhance patient comfort and recovery. Mirtazapine, dexamethasone, and tramadol are commonly used pharmacological agents, each with unique mechanisms of action and efficacy profiles. This study compares their efficacy and safety in PSAS prevention in patients undergoing gynaecological surgeries.

Methods: This randomized controlled trial included 84 patients undergoing gynaecological surgeries under spinal anaesthesia. Participants were randomized into three groups, M Group (Mirtazapine): 30 mg oral dose, 2 hours preoperatively, D Group (Dexamethasone): 8 mg intravenous dose, preoperatively and C Group (Tramadol): 0.5 mg/kg intravenous dose, preoperatively. Primary outcomes included the incidence and severity of shivering, assessed using a 4-point scale. Secondary outcomes were hemodynamic parameters, adverse effects, and the need for rescue therapy. Statistical analysis was conducted using SPSS software.

Results: The pills of mirtazapine were most effective in avoiding shivering (78.6 percent no shivering) than dexamethasone (71.4%) as well as tramadol (53.6%) (p = 0.034). Mirtazapine too showed the least rate of side effects (nausea: 10.7%, pruritus: 0%) and and used the least amount of rescue therapy (7.1%). Hemodynamic stability in each group was noted, and no important difference in heart rate, blood pressure and oxygen saturation existed between the groups.

Conclusion: Mirtazapine is an agent that is the most efficient in the prevention of PSAS, as it has the best result, has few side-effects and acts long-lastingly. Dexamethasone also provides an added value of decreasing inflammation and promoting recovery, but tramadol, in its turn, has increased rates of adverse effects. These results support the idea to optimize the PSAS management in perioperative care.