Impact of intravenous acetaminophen on reducing opioid use after hysterectomy.

Study Objective: To examine the impact of intravenous acetaminophen on the total quantity of opioids (in morphine equivalents) administered within the first 48 hours postoperatively and perioperatively, while still affording patients adequate analgesia, in women who underwent total abdominal hysterectomies.

Design: Retrospective chart review.

Setting: Tertiary care community hospital.

Patients: One hundred women underwent total abdominal hysterectomies performed by a single surgeon: 50 patients received opioids only (fentanyl, morphine, hydromorphone, meperidine, or oxycodone), without the addition of any acetaminophen, between January 1 and March 28, 2011, and 50 patients received intravenous acetaminophen 1000 mg every 6 hours in addition to opioids (multimodal group) between May 1 and July 16, 2012 (time period coincided with the addition of intravenous acetaminophen to the hospital formulary). Patients in both groups were also given nonopioids (celecoxib, dexmedetomidine, aspirin, or tizanidine) perioperatively.

Measurements And Main Results: Patients in both groups had a mean age of 55 years (mean±SD 55±13 yrs in the multimodal group, 55±15 yrs in the opioids-only group), surgery time of ~2 hours (116±51 min in the multimodal group, 118±40 min in the opioids-only group), and an anesthesia time of ~3.5 hours (209±79 min in the multimodal group, 207±79 min in the opioids-only group). During postoperative days 1-2, intravenous acetaminophen reduced opioid use by 31% (mean±SD 47±24 mg in the multimodal group vs 68±37 mg in the opioids-only group, p=0.003) and by 26% during the total perioperative period, defined as preoperative, intraoperative, recovery room, and postoperative days 1-2 (73±24 mg in the multimodal group vs 99±39 mg in the opioids-only group, p=0.001).

Conclusion: The multimodal approach to perioperative analgesic management, which includes concurrent administration of intravenous acetaminophen and opioids, is effective in reducing the total average amount of opioids administered on postoperative days 1-2 and perioperatively. Limitations of this study include its short duration, retrospective design, and single-site setting. These results may not be generalized to patients undergoing other types of obstetric-gynecologic surgeries.