Scheduled Intravenous Acetaminophen Improves Patient Satisfaction With Postcraniotomy Pain Management: A Prospective, Randomized, Placebo-controlled, Double-blind Study

Abstract

Background: Postcraniotomy pain can be difficult to manage with opioids due to opioid-related side effects, including drowsiness, nausea/vomiting, confusion, and pupillary changes, potentially masking the signs of postoperative neurological deterioration. Intravenous (IV) acetaminophen, a nonopioid analgesic, has been reported to have opioid-sparing effects after abdominal and orthopedic surgeries. This study investigates whether IV acetaminophen has similar effects after craniotomy.

Materials and methods: In this prospective, randomized, placebo-controlled, double-blind clinical trial, 100 adult patients scheduled to undergo supratentorial craniotomy for excision of a brain mass were randomized to receive either IV acetaminophen or placebo preincision and then every 6 hours for a total of 24 hours after surgery. Total 24-hour opioid consumption, pain scores, satisfaction with overall pain management, time to meet postanesthesia care unit discharge criteria, and incidence of opioid-related side effects were compared.

Results: There was no difference in the 24-hour postoperative opioid consumption in morphine equivalents between the IV acetaminophen group (median, 11 mg; n=45) and the placebo group (median, 10.1 mg; n=41). No statistically significant difference of visual analog scale pain score was observed between 2 treatment groups. Patient satisfaction with overall postoperative pain management was significantly higher in the IV acetaminophen group than the placebo group on a 1 to 10 scale (8.1±0.4 vs. 6.9±0.4; P=0.03). There was no significant difference in secondary outcomes, including the incidence of opioid-related side effects.

Conclusions: IV acetaminophen, as adjunctive therapy for craniotomy procedures, did not show an opioid-sparing effect in patients for the 24 hours after craniotomy; however, it was associated with improved patient satisfaction regarding overall pain control.

Conflict of interest statement

Conflict of Interest: The authors declare no conflict of interest.

Figures

Figure 1

CONSORT Flow Diagram.

Figure 2

VAS Pain Scores. Box-and-whisker plot displaying the distribution of visual analog scale (VAS) pain score at baseline and follow-up time points. The bottom and top margins of the box indicate 1st and 3rd quartiles, and the band inside the box is the median. The bottom and top of whiskers indicate the maximum and minimum values of all data except outliers. Empty circles represent outliers. “Solid circle” indicates the mean of VAS in the Acetaminophen group and “*” indicates the mean of VAS in the control group.