Opioid-free analgesia: is it achievable in open colorectal surgery without neuraxial block?

This study aimed to evaluate feasibility and results of opioid-free analgesia (OFA) in open colorectal operation, and to determine factors influencing successful OFA.

This study included 89 adult patients having elective open colectomy and/or proctectomy (without neuraxial or nerve block) from 2018 to 2020 in a university hospital. Current opioid users were excluded. Non-opioid analgesics were given based on patient's comorbidity. Successful OFA was determined by whether patients required morphine administered by intravenous patient-controlled analgesia. Clinical outcomes were prospectively collected and compared between OFA group and the other. Factors influencing successful OFA were determined (Trial registration number: TCTR20211220007).

The studied population had an average age of 68±12 years. Colorectal resection with stoma formation was performed in 17 cases (19%). OFA was achieved in 15 cases (17%). Median amount of morphine used was 18 mg per person (interquartile range 10-30) in those requiring opioid. There was no significant difference in patient's characteristics, intraoperative parameters and clinical outcomes between OFA group and the other except lower pain scores in the OFA group. The regimen of perioperative analgesia was the only predictor of successful OFA. Patients receiving multimodal analgesia with acetaminophen, selective cyclooxygenase-2 inhibitor and nefopam had the highest chance of successful OFA (5 of 15 cases, 33%).

This study showed that OFA was achievable in 17% of patients undergoing open colorectal resection without neuraxial block. The regimen of perioperative analgesia was the predictor of successful OFA.