Comparison Of Intrathecal Morphine and Buprenorphine With Ropivacaine To Attenuate Pressure Response To Carboperitoneum in Total Laparoscopic Hysterectomy Under General Anaesthesia

Abstract

Background: Total laparoscopic hysterectomy (TLH) is associated with pneumoperitoneum-induced sympathetic stimulation and postoperative pain that can compromise haemodynamic stability. Intrathecal opioids combined with ropivacaine may attenuate this stress response and enhance analgesia, but direct comparative data on buprenorphine versus morphine in this setting are limited.

Objective: To compare intrathecal buprenorphine and intrathecal morphine, each combined with 0.75% hyperbaric ropivacaine, for attenuation of the pressor response to carboperitoneum, postoperative analgesic profile, and opioid-related adverse effects during TLH under general anaesthesia.

Methods: In this randomized controlled trial, 80 ASA I–II women aged 30–60 years undergoing elective TLH were allocated equally to Group B (intrathecal buprenorphine 60 mcg with 1 ml 0.75% hyperbaric ropivacaine) or Group M (intrathecal morphine 100 mcg with 1 ml 0.75% hyperbaric ropivacaine), followed by standardized general anaesthesia. Heart rate and mean arterial pressure (MAP) were recorded at baseline, during spinal anaesthesia, at intubation, and serially through carboperitoneum. Postoperative pain (VAS) was assessed for 24 hours along with time to first rescue analgesia, total rescue doses, and adverse effects.

Results: Baseline characteristics were comparable between groups. MAP rose more during spinal anaesthesia in Group B than Group M (4.35 ± 4.83 vs 0.88 ± 5.15 mmHg, p = 0.001) and remained consistently higher in Group B throughout carboperitoneum (all p ≤ 0.002 on repeated-measures ANOVA). VAS scores over 24 hours were significantly lower in Group M (p = 0.001), while time to first rescue analgesia was longer in Group B (18.16 ± 3.59 vs 16.05 ± 3.38 hours, p = 0.015); total 24-hour rescue analgesic requirement did not differ significantly. Nausea was more frequent in Group M (37.5% vs 10%, p = 0.004); vomiting, pruritus, urinary retention and respiratory depression were low and comparable, with no respiratory depression in either group.

Conclusion: Intrathecal morphine 100 mcg with ropivacaine provides superior attenuation of carboperitoneum-induced MAP elevation and lower postoperative pain scores than intrathecal buprenorphine 60 mcg, at the cost of more postoperative nausea; buprenorphine offers a modestly longer interval to first rescue analgesia with a more favourable nausea profile. Opioid choice can therefore be individualized based on hemodynamic priorities and tolerability.