The feasibility and safety in using acetaminophen with fentanyl for pain control after liver resection with regards to liver function: A prospective single-center pilot study in Japan

Introduction: Acetaminophen has been widely used as an analgesic agent after various types of surgery. However, acetaminophen may sometimes induce severe liver dysfunction, which can occasionally lead to the need for liver transplantation. The aim of this study was to assess the feasibility and efficacy of administering acetaminophen to patients after liver resection (LR). Patients and methods: The prospective study included 50 patients who underwent the following procedures: partial LR (n = 21) and more than one section LR (n = 29). Pain control was provided with continuous intravenous fentanyl and acetaminophen every 6 hours (within 2 days). We analyzed the liver function and blood concentration of acetaminophen at 1 and 3 days after LR using high performance liquid chromatography (HPLC), and investigated the results of partial and more than one section LR, and also examined the degree of liver fibrosis. Results: The alanine transaminase level on postoperative days 1, 5, and 7 and total bilirubin on postoperative days 1 to 5 after LR in patients with more than one section LR was significantly higher than the levels in patients with partial resection. No patients developed liver failure. The blood concentration of acetaminophen by HPLC was significantly elevated in patients with resection of more than one section in comparison to the partial resection group. Conclusion: The safety of acetaminophen was evaluated in Japanese patients who underwent different types of LR with different degrees of liver fibrosis.