Analgesic effects of different patient-controlled intravenous analgesia infusion modes post cesarean section under multimodal analgesia: a retrospective cohort study

The study compared the efficacy of patient-controlled intravenous analgesia with and without background infusion in 250 women after planned cesarean section. All patients received multimodal analgesia including epidural hydromorphone, bilateral transversus abdominis plane block with 266 mg liposomal bupivacaine, and oral acetaminophen. No significant differences were found between groups in the number of analgesic requests in the first 24 hours (3 versus 2, p = 0.829) or in the second 24 hours (5 versus 4, p = 0.303), nor in pain scores at rest and during movement. However, the background infusion group had higher total opioid doses over 48 hours (54.6 mg versus 3.5 mg morphine equivalent, p < 0.001). The results demonstrate that adding background infusion did not improve analgesic efficacy and increased opioid exposure.