A randomized controlled trial of postoperative intravenous acetaminophen plus thoracic epidural analgesia vs. thoracic epidural analgesia alone after gastrectomy for gastric cancer

BACKGROUND: Acetaminophen is used in multimodal therapy for postoperative pain management. However, the additional effects of acetaminophen in combination with thoracic epidural analgesia (TEA) are not well understood. This prospective, multicenter randomized study was conducted to evaluate the efficacy of routine intravenous (i.v.) acetaminophen in combination with TEA for the management of postoperative pain in gastric cancer surgery. METHODS: A total of 120 patients who underwent distal gastrectomy were randomly assigned in a 1:1 ratio to receive i.v. acetaminophen every 6 h and TEA during the first 3 postoperative days (acetaminophen group) or TEA alone (control group). The primary endpoint was the sum of TEA rescue doses during the first 2 postoperative days. RESULTS: Final analysis included 58 patients in the acetaminophen group and 56 patients in the control group. The median number of TEA rescue doses was significantly lower in the acetaminophen group compared with the control group (3.0 vs. 8.0, p = 0.013). The median area under the curve (AUC) of the pain scores at coughing was significantly less in the acetaminophen group compared with the control group (285 vs. 342, p = 0.046) without an increase in postoperative complications. TEA rescue doses and pain score AUCs were significantly reduced by acetaminophen in patients who underwent open gastrectomy (p = 0.037 and 0.045), whereas there was no significant difference between patients who underwent laparoscopic gastrectomy in the two groups. CONCLUSIONS: In gastric cancer surgery patients, routine i.v. acetaminophen in combination with TEA provides superior postoperative pain management compared with TEA alone.