Efficacy of tramadol in preventing postoperative shivering using thiopentone or propofol as induction agent: A randomized controlled trial

Background: Postoperative shivering (POS) is a common and distressing experience occurring in up to 60% patients postoperatively. This study was designed to compare the efficacy of tramadol in preventing POS when used with two different induction agent, propofol or thiopentone. Materials and Methods: One hundred and twenty-four ASA I and II adult patients, aged between 18-60 years, undergoing general anesthesia of intermediate duration (60-240 min) for orthopedic, gynecological, and general surgical procedures were randomly divided to receive either thiopentone or propofol as induction agent. Each group was further subdivided (31 patients in each group) to receive either tramadol or saline 15 min before wound closure. Presence of POS after extubation till discharge from post anesthesia care unit (PACU) was recorded at six different time intervals. Results: The highest incidence of POS was observed in thiopentone-saline (TS) group 77.4%, while the lowest (12.9%) was in propofol-tramadol (PT) group (P < 0.001). Total number of shivering episodes was 122 out of which, 35 (28.7%) were of grade 2 and 3 (significant shivering) requiring treatment. The incidence of significant shivering was similar to the episodes of POS, highest in TS group and lowest being in PT group (P < 0.05). Conclusion: The prophylactic use of tramadol in a dose of 1 mg/kg with propofol as an induction agent significantly reduces the incidence of POS in patients recovering from general anesthesia of intermediate duration.