Analgesic Safety of Periodic Intravenous Infusion of Acetaminophen After Hepatectomy: A Propensity Score Matching Analysis

Background and Aim: Acetaminophen is an often-used analgesic for management of postoperative pain; it is not associated with hypomotility of the gastrointestinal tract or postoperative nausea and vomiting. It may, however, negatively affect liver function. Thus, acetaminophen is rarely used after hepatectomy and there are few studies pertaining to the analgesic safety of such use. We investigated the analgesic safety of periodic intravenous infusion of acetaminophen following hepatectomy. Patients and Methods: The study included 92 patients who had undergone hepatectomy without biliary reconstruction at St. Marianna University Hospital between January 2014 and November 2018. These patients were identified from among a larger group of patients, and propensity score matching allowed for the creation of two study groups: 46 patients who had undergone periodic intravenous infusion of acetaminophen for postoperative pain management (Group A), and 46 control patients who had undergone bolus injections of the non-steroidal antiinflammatory drug upon request (Group C). The two groups were then compared retrospectively in terms of clinical characteristics; operative variables; details regarding postoperative analgesia; concentrations of serum liver enzymes (total bilirubin [TBL], aminotransaminases aspartate aminotransferase [AST], alanine aminotransferase [ALT], alkaline phosphatase [ALP] and gamma-glutamyl transpeptidase [γGTP]) determined preoperatively, on postoperative days (PODs) 1, 3 and 7, and between PODs 14 and 28; and in-hospital outcomes and complications. Results: Patients’ clinical characteristics and operative variables did not differ between the two groups. Of the liver enzymes, only the serum γGTP concentrations observed on POD 7 and POD 14 differed significantly (p=0.003 and p=0.017, respectively). No patient suffered CTCAE Grade ≥ 3 hepatic failure, and there was no mortality. Conclusion: Results of our study indicate that periodic intravenous infusion of acetaminophen after hepatectomy is a safe means of managing patients’ postoperative pain.