Effect of opioid-free anesthesia on post-operative period in cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a propensity score matched study.

Background: Postoperative pain after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is important. It appears essential to reduce postoperative pain and morphine consumption.

Methods: Retrospective study in a university hospital comparing patient benefiting from CRS-HIPEC under opioid-free anesthesia (OFA; dexmedetomidine) to those anesthetized with opioid anesthesia (OA; remifentanil) using a propensity score matching method. The main objective was the impact of OFA on postoperative morphine consumption in the first 24 h after surgery.

Results: 102 patients were included, matching on the propensity score allowed selecting 34 unique pairs analyzed. Morphine consumption was lower in the OFA group than in the OA group (3.0 [0.00-11.0] mg/24 h vs. 13.0 [2.5-25.0] mg/24 h; p = 0.02). In multivariable analysis, OFA was associated with a reduction of 7.2 [0.5-13.9] mg of postoperative morphine (p = 0.04). The rate of renal failure with a KDIGO-score > 1 was lower in the OFA group than in the OA group (12% vs. 38%; p = 0.01). There was no difference between groups concerning length of surgery/anesthesia, norepinephrine infusion, volume of fluid therapy, post-operative complications, rehospitalization or ICU readmission within 90 days, mortality, and postoperative rehabilitation.

Conclusion: Our results suggest that OFA for CRS-HIPEC patients appears safe and is associated with less postoperative morphine use and acute kidney injury.