Postoperative Intravenous Acetaminophen for Craniotomy Patients: A Randomized Controlled Trial

OBJECTIVE: To determine whether opioids during the first 24 postoperative hours were significantly altered when receiving intravenous (IV) acetaminophen during that time compared with those receiving placebo (normal saline). METHODS: One hundred forty patients undergoing any type of craniotomy were randomly assigned to receive either 1 g of IV acetaminophen or placebo upon surgical closure, and every 6 hours thereafter, up to 18 hours post-operatively. Analgesic requirements for the first 24 postoperative hours were recorded. Time to rescue medications in the postanesthesia care unit (PACU)/intensive care unit (ICU), amount of rescue medication, ICU and hospital lengths of stay, number of successful neurological examinations, sedation, delirium, satisfaction, and visual analog scale pain scores were also recorded. RESULTS: Compared with the placebo group, more patients in the IV acetaminophen group (10/66 [15.2%] vs. 4/65 [6.2%] in the placebo group) did not require opioids within the first 24 postoperative hours, but this did not reach significance (odds ratio, -9.0%, 95% confidence interval -20.5% to 1.8%; P = 0.166). Both groups had similar times to rescue medications, amounts of rescue medications, ICU and hospital lengths of stay, numbers of successful neurological examinations, sedation, delirium, satisfaction scores, visual analog scale pain scores, and temperatures within the first 24 postoperative hours. CONCLUSIONS: The opioid requirements within the first 24 postoperative hours were similar in the placebo and acetaminophen groups. This study is informative for the design and planning of future studies investigating the management of postoperative pain in patients undergoing craniotomies.