Intravenous acetaminophen vs saline in perioperative analgesia with laparoscopic hysterectomy.

BACKGROUND: 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.

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

STUDY DESIGN: 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.

RESULTS: 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.

CONCLUSION: 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.