Intravenous acetaminophen vs saline in perioperative analgesia with laparoscopic hysterectomy

Opioids are effective for the treatment of postoperative pain but can cause nausea and are associated with dependency with long-term use. Nonopioid medications such as acetaminophen offer the promise of decreasing these nondesirable effects while still providing patient comfort.

The purpose of this study was to compare intravenous acetaminophen with placebo and to evaluate postoperative pain control and opioid usage after laparoscopic hysterectomy.

We conducted a prospective double-blind randomized study with 183 patients who were assigned randomly (1:1) to receive acetaminophen or placebo (Canadian Task Force Design Classification I). Patients received either 1000 mg of acetaminophen (n=91) or a placebo of saline solution (n=92) at the time of induction of anesthesia and a repeat dose 6 hours later. Both groups self-reported pain and nausea levels preoperatively and at 2, 4, 6, 12, and 24 hours after extubation with the use of a visual analog scale with a score of 0 for no pain to 10 for highest level of pain. Patients self-reported pain, nausea, and postoperative oral opiates that were taken after discharge. All opiates were converted to milligram equivalents of oral morphine for standardization.

There were no significant differences in generalized abdominal pain at any time point postoperatively that included 2 hours (placebo 3.6±2.5 vs acetaminophen 4.4±2.5; P=.07) and up to 24 hours (placebo 3.3±2.4 vs acetaminophen 3.6±2.5; P=.28). Similar results were observed for nausea scores. There were no differences in opioid consumption at any time point including intraoperatively (placebo 4.4±3.9 vs acetaminophen 3.3±4.0; P=.06), post anesthesia care unit (placebo 10.5±10.3 vs acetaminophen 9.7±10.3; P=.59), and up to 24 hours after surgery (placebo 1.4±2.0 vs acetaminophen 1.6±2.1; P=.61). There were no differences in demographics or surgical data between groups.

There was no difference between acetaminophen and placebo groups in postoperative pain, satisfaction scores, or opioid requirements. Given the relatively high cost ($23.20 per dose in our study), lack of benefit, and available oral alternatives, our results do not support routine use during hysterectomy.