Intravenous Acetaminophen Does Not Decrease Persistent Surgical Pain After Cardiac Surgery.

OBJECTIVE: The authors investigated the hypothesis that perioperative acetaminophen reduces incisional pain at 30 and 90 days.

DESIGN: This was a prospective, randomized, double-blind trial.

SETTING: Tertiary-care hospital (single center) cardiac surgery unit.

PARTICIPANTS: Patients undergoing cardiac surgery via median sternotomy.

INTERVENTIONS: Patients were assigned randomly to intravenous (IV) acetaminophen or IV placebo. Patients were given 4 doses of 1 g of IV acetaminophen or an equal volume of saline placebo over 15 minutes every 6 hours for 24 hours starting in the operating room after sternal closure.

MEASUREMENTS AND MAIN RESULTS: Study participants were assessed by phone for incisional pain severity 30 and 90 days after surgery. Those reporting any incisional pain were asked to complete the Neuropathic Pain Questionnaire-Short Form and the modified Brief Pain Inventory. Patients were compared on 30- and 90-day incisional pain severity using separate multivariable linear regression models. IV acetaminophen had no effect on 30- and 90-day incisional pain, with an estimated difference in means (confidence interval) of 0.06 (-0.87 to 0.99) at 30 days (p = 0.88) and 0.07 (-0.71 to 0.86) at 90 days (p = 0.83). Low pain severity, neuropathic pain, and interference at both 30 and 90 days after surgery, regardless of treatment group, were observed.

CONCLUSIONS: IV acetaminophen did not reduce the incidence or intensity of incisional pain at 30 days and 90 days after surgery.