Maximizing postoperative comfort: the role of intraoperative acetaminophen administration in reducing shivering—a randomized controlled trial

Abstract

Background: Shivering is an undesirable, and very common, postoperative event that causes a great deal of physiological stress. While several pharmacologic treatments are available, the efficacy of prophylactic (long-term) intravenous (IV) acetaminophen treatment has yet to be thoroughly studied. Objectives: To compare the effectiveness of prophylactic intravenous acetaminophen in preventing postoperative shivering in patients undergoing surgery under general anaesthesia. Methods: This was a randomized controlled trial that was carried out in the department of Anaesthesiology, Shalamar Hospital, a tertiary care hospital Lahore, from March 2026 to Jun 2026. 76 adult patients (ASA I/II) undergoing elective surgeries under general anesthesia were included. Participants were randomly assigned to either receive a 100 mL of normal saline with 1 g of IV acetaminophen over 15 minutes after induction (Group A, n = 38) or to receive a 100 mL of normal saline placebo for 15 minutes after induction (Group S, n = 38). We assessed shivering in the post anesthesia care unit using a standard 0–4 scale. Results: The incidence of postoperative shivering was significantly less in the acetaminophen group (13.2%) than in the placebo group (52.6%) (p < 0.001). In addition, Group A had a later start of shivering with a significant decrease in the number of anti-shivering rescue calls (p<0.05). Complication profiles did not differ significantly between the groups. Conclusions: IV acetaminophen administration during surgery can effectively reduce the incidence and intensity of postoperative shivering during general anesthesia, thereby improving the comfort of patients during surgery.