Effect of Fentanyl-Based Intravenous Patient- Controlled Analgesia with and without Basal Infusion on Postoperative Opioid Consumption and Opioid-Related Side Effects: A Retrospective Cohort Study

Purpose: We aimed to investigate the effect of a basal opioid infusion in fentanyl-based intravenous patient-controlled analgesia (IV-PCA) on postoperative opioid consumption, pain intensity, and occurrence of opioid-related side effects. Patients and Methods: We retrospectively reviewed 2097 consecutive patients who received IV-PCA after elective general, thoracic, urologic, and plastic surgery under general anesthesia between June 2019 and October 2019. The patients were divided into two groups: IV-PCA with basal infusion (basal group) and IV-PCA without basal infusion (no basal group). We performed a propensity score matching (PSM) analysis to adjust for baseline differences between both groups. We compared the fentanyl PCA consumption (mcg), pain intensity, rescue analgesic administration, and occurrence of opioid-related side effects (nausea, vomiting, somnolence or dizziness, and overall side effects) during the first 48 hours postoperatively between the two groups before and after PSM. Results: We analyzed 1317 eligible patients. Of these, 757 (57.5%) patients received IVPCA without basal infusion. The PSM of the total cohort yielded 539 pairs of cases. After PSM, the fentanyl PCA consumption was significantly lower in the no basal group at 48 hours postoperatively as compared to the basal group (at 24 hours, the median difference: -80 mcg, P