Prevention of post-anaesthetic shivering under subarachnoid block for lower limb surgeries: A randomised controlled study comparing nefopam and tramadol

Objectives: Shivering is one of the frequent, undesirable and unpleasant effects of spinal anaesthesia that can be prevented by several means including, pharmacological and non-pharmacological methods. Methods: Patients between 18 and 65 years were randomly assigned into two groups (A or B). Group A patients received intravenous 0.3mg/kg nefopam while Group B patients received intravenous 0.5mg/kg tramadol just before the institution of subarachnoid block. The parameters assessed were: the incidence of post-spinal anaesthetic shivering, its' severity, and the side-effects of the two drugs. Changes in haemodynamic parameters, temperature, peripheral arterial oxygen saturation and temperature were also evaluated. Results: Thirty- four patients (100%) in group A and twenty-eight patients (82.35%) in group B, were shivering-free. Thus, only six patients (17.65%) in Group B shivered intra-operatively; p= 0.025, which is statistically significant. The severity of post-anaesthetic shivering was assessed to be grade 2 in three patients (8.82%), while it was grade 1 in the remaining three patients (8.82%). Four patients experienced nausea in group B, but none in group A; p = 0.114 No episode of vomiting was observed in both groups. Conclusion: Nefopam is better than tramadol for the prevention of intraoperative shivering under spinal anaesthesia.