Use of Intravenous Acetaminophen to Reduce Opioid Use in Patients Undergoing Bariatric Surgery at a Community Teaching Hospital

Purpose: The use of intravenous (IV) acetaminophen has been evaluated in several clinical trials and systematic reviews and has been shown to be an effective pain medication that can reduce the need for opioids. Recently, the Pharmacy and Therapeutics (P&T) committee at Atlanta Medical Center (AMC) approved an extension of the use of IV acetaminophen from one dose intra-operatively to four doses over 24 hours for 30 patients. The objective of this study was to compare the use of IV acetaminophen dosed at 1 g every 6 hours, to the previous use of 1 g for one dose at AMC in patients undergoing bariatric surgery. Methods: Patients were divided into two groups; control group consisting of patients who received one dose of IV acetaminophen in the operating room (OR) and the intervention group consisting of patients who received four doses of IV acetaminophen over a 24 hour period. The primary endpoint was the total amount of opioids required by patients over 24 hours measured in morphine equivalents. The secondary endpoints were the adverse effects and average pain scores. Results: The final sample consisted of 30 patients in each group. The total amount of opioids used by the intervention group was 28.3% lower than that of the control group. The average amount of opioids required by patients in the intervention group was 13.08 mg compared to 18.23 mg in the control group (p = 0.15). The only adverse event experienced within the groups was nausea/vomiting (p = 0.1). The average pain score reported by patients in the intervention group was 4.58 compared to 6.12 in the control group (p = 0.04). Conclusion: Although not powered to show statistical significance between groups, IV acetaminophen is associated with a reduction in opioid use, and improved pain scores over a 24 hour period. Adequately powered studies are needed to determine the long term benefits of acute opioid reduction.