Analgesic Effect of Ropivacaine Combined with Hydromorphone following Surgery for Mixed Hemorrhoids: A Pilot Study

BACKGROUND: Postoperative pain is a major adverse effect of surgery for mixed hemorrhoids. We evaluated whether spinal anesthesia with ropivacaine and hydromorphone provided safe and effective analgesia after surgery for mixed hemorrhoids. METHODS: This single-center, double-blind pilot study included patients with mixed hemorrhoids who underwent a procedure for prolapse and hemorrhoids (PPH) and external hemorrhoidectomy under spinal anesthesia at Zhejiang Hospital, China (October 2020 to December 2020). Patients were randomized to a hydromorphone group (spinal anesthesia with 0.5% ropivacaine and 75 μg hydromorphone) or morphine group (spinal anesthesia with 0.5% ropivacaine and 150 μg morphine). Pain scores (numerical rating scale), incidences of vomiting and itching, and length of hospital stay (LoS) were recorded at 6, 12, 18, and 24 hours after surgery. RESULTS: The analysis included 40 patients in each group. Median (interquartile range) pain score in the hydromorphone group was higher than that in the morphine group at 12 hours (1 (0–2] vs. 0 (0–2), p=0.044) but not significantly different between groups at 6 hours (0 (0–1) vs. 0 (0-0) p=0.228), 18 hours (2 (2–3) vs. 2 (1–3) p=0.060) or 24 hours (2 (2–3) vs. 2 (1–3) p=0.081). The hydromorphone group had a lower incidence of pruritus than the morphine group (47.5% vs. 67.5%, p=0.018). There were no significant differences between groups in vomiting incidence or LoS. CONCLUSION: In patients with mixed hemorrhoids, spinal anesthesia with ropivacaine/hydromorphone has a comparable analgesic effect and a lower incidence of pruritus during the first 24 hours after surgery than spinal anesthesia with ropivacaine/morphine.