Oxycodone is superior to morphine for pain relief following peroral oesophageal myotomy: a prospective, randomized, controlled trial

INTRODUCTION: Patients underwent peroral endoscopic myotomy (POEM) for treating achalasia suffered with mild to moderate, sometimes even severe postoperative pain. AIM: To evaluate the efficacy of oxycodone on postoperative analgesia of patients undergoing PEOM. MATERIAL AND METHODS: In this prospective, double-blinded, randomized, controlled trial, patients with achalasia were recruited and received 0.08 mg/kg oxycodone or morphine 15 min before the end of the POEM procedure. The short-form McGill questionnaire (SF-MPQ) was used to measure the postoperative pain at 0, 2, 6, 24, and 48 h after surgery, which included the visual analogue scale (VAS), the present pain intensity (PPI) scale, and the pain rating index (PRI). RESULTS: A total of 73 patients were included, of whom 36 received oxycodone, and 37 received morphine. Compared with morphine, patients received oxycodone were associated with lower VAS in the first 24 h postoperatively (1.64 ±0.76 vs. 2.14 ±1.23, p = 0.042) as well as PPI at 2 h (1.11 ±0.40 vs. 2.22 ±0.89, p < 0.001), 6 h (1.42 ±0.55 vs. 2.08 ±0.92, p < 0.001) and 24 h (1.06 ±0.23 vs. 1.30 ±0.46, p = 0.006). Patients who received oxycodone experienced lower sensory McGill pain score than those who received morphine at 2, 6, 24, and 48 h after surgery (p < 0.05). Significantly lowered affective McGill pain score was observed in the oxycodone group at 0, 2, and 24 h postoperatively. Regarding the PRI, the sum of both sensory and affective McGill pain scores, patients with oxycodone therapy were associated with better scores postoperatively. CONCLUSIONS: Oxycodone appears to be superior to morphine in dealing with post-POEM pain, which has distinct visceral pain characteristics.