Preoperative intravenous acetaminophen does not appear to reduce postoperative pain in women undergoing surgery for pelvic organ prolapse, new research suggests.
“Owing to its lack of clinical benefit, routine use of IV acetaminophen as the sole preemptive analgesia agent is not supported by this study,” reported Lindsay C. Turner, MD, of the department of obstetrics and gynecology at the Allegheny Health Network in Pittsburgh, and her coauthors.
In a double-blind placebo-controlled trial, published in Obstetrics & Gynecology, Dr. Turner and her coauthors randomized 202 women undergoing laparoscopic or vaginal surgery to either 1,000 mg intravenous acetaminophen or saline.
Among the 162 patients for whom pain score data were available at baseline and 24 hours after surgery, there were no significant differences in the mean change in pain scores from baseline to 24 hours between the acetaminophen group and the placebo group, or at any other time point in the 24 hours, regardless of surgical route.
, which was similar between the intervention and placebo groups, irrespective of surgical route.
The women in the study also were asked to complete pain diaries for the 7 days after their operation. This revealed no significant difference between the acetaminophen and placebo groups in narcotic pain relief use during that week. Patients used a median of 30 of the narcotic tablets prescribed at discharge, which represented less than one-quarter of the total tablets prescribed.
“Although preoperative IV acetaminophen is included in many extended recovery pathways owing to its improvement in pain scores and reduction in narcotic use after many other types of procedures, the use of IV acetaminophen alone before surgery for [pelvic organ prolapse] is not supported,” wrote Dr. Turner and her coauthors.
The rates of side effects, such as nausea, drowsiness, itching, or dizziness also were similar between the two groups. However, Dr. Turner and her coauthors noted a significantly higher rate of urinary retention among women who underwent surgery by the vaginal route and received intravenous acetaminophen, compared with those who received placebo (59.2% vs. 33.3%; P = .01).
“The increased rates of urinary retention with IV acetaminophen in women undergoing vaginal surgery are surprising, because more women in the placebo group underwent posterior repair, which historically has been thought to increase risks of postoperative urinary retention,” the authors wrote. They suggested that the medium in which the IV acetaminophen was suspended might have had a diuretic effect but said that further study was needed to explore the observation.
Dr. Turner and her coauthors cited as a limitation the absence of primary outcome data for 40 of the patients. They said the inconsistency found in the patients’ completion of postoperative and pain diaries was a limitation.
The study was supported by the American Urogynecologic Society Pelvic Floor Disorders Research Foundation. No conflicts of interest were declared.
SOURCE: Turner LC et al. Obstet Gynecol. 2019;133:492-502.