Opioid-sparing anesthesia and patient-reported outcomes after open gynecologic surgery: a historical cohort study

Purpose: Dexmedetomidine and ketamine may be administered intraoperatively as continuous infusions to provide opioid-sparing anesthesia. Recent evidence has yielded controversial results regarding the impact of opioid-free anesthesia on postoperative complications, and there is a gap in knowledge regarding patient-reported outcomes (PROs). This study aimed to determine the impact of opioid-sparing anesthesia and opioid-based anesthesia on PROs among gynecologic patients within an enhanced recovery after surgery (ERAS) program. Methods: We formed a single-center historical cohort from patients enrolled in another study who underwent open gynecologic surgery on an ERAS program from November 2014 to December 2020 (n = 2,095). We identified two cohorts based on the type of balanced anesthesia administered: 1) opioid-sparing anesthesia defined as the continuous infusion of dexmedetomidine and ketamine (adjuvants) during surgery or 2) opioid-based anesthesia (no adjuvants). We measured the quality of postoperative recovery using the MD Anderson Symptom Inventory (MDASI), a 29-item validated tool that was administered preoperatively, daily while admitted, and weekly after discharge until week 6. The primary outcome was interference with walking. We matched both cohorts and used a multilevel linear mixed-effect model to evaluate the effect of opioid-sparing anesthesia on the primary outcome. Results: In total, 498 patients were eligible (159 in the opioid-sparing anesthesia cohort and 339 in the opioid-based anesthesia cohort), of whom 149 matched pairs were included in the final analysis. Longitudinal assessment showed no significant or clinically important difference in interference with walking (P = 0.99), general activity (P = 0.99), or other PROs between cohorts. Median [interquartile range (IQR)] intraoperative opioid administration (expressed as morphine milligram equivalents [MME]) among matched patients in the opioid-sparing anesthesia cohort was 30 [25–55] mg vs 58 [8–70] mg in the opioid-based anesthesia cohort (P < 0.01). Patients in the opioid-sparing anesthesia cohort had a lower opioid consumption in the postanesthesia care unit than those in the opioid-based anesthesia cohort (MME, 3 [0–10] mg vs 5 [0–15] mg; P < 0.01), but there was no significant difference between cohorts in total postoperative opioid consumption (MME, 23 [0–94] mg vs 35 [13–95] mg P = 0.053). Conclusions: In this single-center historical cohort study, opioid-sparing anesthesia had no significant or clinically important effects on interference with walking or other PROs in patients undergoing gynecologic surgery compared with opioid-based anesthesia. Opioid-sparing anesthesia was associated with less short-term opioid consumption than opioid-based anesthesia.