Comparative Evaluation of Efficacy and Safety of Intramuscular Butorphanol vs Epidural Butorphanol as Postoperative Analgesia in Patients Undergoing Lower Abdominal and Lower Limb Surgeries: A Randomized-controlled Study

Abstract

Context: Intramuscular (IM) butorphanol can be a convenient postoperative analgesia compared to epidural (EP) route. Aims: Compare the efficacy and safety of IM vs EP butorphanol (1 mg/2 mg) as postoperative analgesia. Settings and design: A randomized-controlled study. Materials and methods: This study was conducted on 120 adult patients of either sex in the age group of 20-60 years, undergoing lower abdominal or lower limb surgeries (American Society of Anesthesiologists [ASA] class-I/II). Patients were randomized to butorphanol intramuscularly (IM group) or EP injection (EP group). Each group had two equal subgroups where patients received either 1 mg or 2 mg by the respective route. The primary outcomes were onset of analgesia, peak time of analgesia, and duration of analgesia. Pain was assessed on a 0-10 visual analog scale (VAS), and vital parameters were assessed at baseline and after 10, 20, 30, 60, 90, 120, and 180 minutes. Clinical safety was assessed by the adverse events. Results: The duration of analgesia provided by both the routes was comparable (293.0 minutes IM and 270.25 minutes EP). However, duration of analgesia was longer (p, 0.043) with 2 mg compared to 1 mg. Similarly, the onset of analgesia, pain scores, and peak time of analgesia were similar (p > 0.05) in the two groups. No differences in the hemodynamic parameters and respiratory rate were observed in the two groups. Higher incidence of all the side effects (sedation, somnolence, pruritus) was observed with IM administration. All side effects were clinically insignificant. Conclusion:Intramuscular butorphanol is as effective as an EP for the management of immediate postoperative pain. Keymessages: Intramuscular analgesics could be more convenient and safer compared to EP administration. Butorphanol administered by the IM route is as effective and safe compared to EP administration.