Effect of intraoperative methadone in robot-assisted cystectomy on postoperative opioid requirements: A randomized clinical trial.

Background: Postoperative pain management is a challenge after robot-assisted cystectomy (RAC). Methadone has a long duration of action, and we therefore hypothesized that a single dose of intraoperative methadone would reduce postoperative opioid requirements and pain intensity in bladder cancer patients undergoing RAC.

Methods: We conducted a blinded randomized controlled clinical trial from July 2020 to August 2023. Patients scheduled to undergo RAC because of bladder cancer were randomized to receive intraoperative methadone (0.15 mg/kg^-1) or morphine (0.15 mg kg^-1) 1 h before endotracheal extubation. The primary outcome was opioid requirements after 24 h. Secondary outcomes were opioid requirements after 3 h, pain intensity at rest and during coughing, postoperative nausea and vomiting (PONV), sedation, hypoxemia, hypoventilation, time spent in the post-anesthetic care unit, and patient satisfaction.

Results: A total of 114 patients were randomized. Data from 99 patients (14 females, 85 males; mean age 69.8 ± 8.9 years) were available for analysis; 52 received methadone and 47 received morphine. Opioid consumption was similar between the methadone group and morphine group at 3 h (median, mg, 45 (IQR 30 to 75) vs. 45 (IQR 15 to 82.5) p = .97) and at 24 h (median, mg, 125 (IQR 75 to 198.5) versus 105 (IQR 72 to 157.5), p = .29). Pain intensity was significantly lower in the morphine group at 48 h compared with the methadone group. Patient satisfaction at 24 h was increased in the methadone group compared with the morphine group (median, (IQR), NRS; 9 (IQR 7 to 10) versus 7 (IQR 4 to 9), p = .020). There were no differences between treatment groups in terms of time spent in the post-anesthetic care unit and the occurrence of opioid-related side effects.

Conclusion: A single dose of intraoperative methadone does not reduce postoperative opioid requirements compared with a single dose of morphine in bladder cancer patients undergoing RAC.