Hepatic resection is associated with reduced postoperative opioid requirement

Background and Aims: Postoperative pain can significantly affect surgical outcomes. As opioid metabolism is liver-dependent, any reduction in hepatic volume can lead to increased opioid concentrations in the blood. The hypothesis of this retrospective study was that patients undergoing open hepatic resection would require less opioid for pain management than those undergoing open pancreaticoduodenectomy. Material and Methods: Data from 79 adult patients who underwent open liver resection and eighty patients who underwent open pancreaticoduodenectomy at our medical center between January 01, 2010 and June 30, 2013 were analyzed. All patients received both general and neuraxial anesthesia. Postoperatively, patients were managed with a combination of epidural and patient-controlled analgesia. Pain scores and amount of opioids administered (morphine equivalents) were compared. A multivariate lineal regression was performed to determine predictors of opioid requirement. Results: No significant differences in pain scores were found at any time point between groups. Significantly more opioid was administered to patients having pancreaticoduodenectomy than those having a hepatic resection at time points: Intraoperative (P = 0.006), first 48 h postoperatively (P = 0.001), and the entire length of stay (LOS) (P = 0.002). Statistical significance was confirmed after controlling for age, sex, body mass index, and American Society of Anesthesiologists physical status classification (adjusted P = 0.006). Total hospital LOS was significantly longer after pancreaticoduodenectomy (P = 0.03). A multivariate lineal regression demonstrated a lower opioid consumption in the hepatic resection group (P = 0.03), but there was no difference in opioid use based on the type of hepatic resection. Conclusion: Patients undergoing open hepatic resection had a significantly lower opioid requirement in comparison with patients undergoing open pancreaticoduodenectomy. A multicenter prospective evaluation should be performed to confirm these findings.