Caudal-Threaded Versus Direct Lumbar/Thoracic Epidural Catheters in Small-Weight Infants—A Single-Center Retrospective Observational Study

Background: Continuous epidural analgesia is widely used for postoperative pain management in small infants. Epidural catheters may be inserted via a caudal-threaded approach or by direct lumbar/thoracic placement; however, comparative data on placement success, clinical use, postoperative analgesic outcomes, and complications remain limited. This study compared these two epidural techniques in small-weight infants undergoing surgery. Methods: This retrospective observational cohort study included all infants admitted to the Neonatal Intensive Care Unit at UPMC Children’s Hospital of Pittsburgh with documented epidural catheter placement in the chart between January 2018 and December 2024. Demographic and perioperative data were extracted from the electronic medical record. Outcomes included technical success of catheter placement; patient, surgical, and epidural characteristics; epidural medications; postoperative pain and sedation scores; opioid consumption; and epidural catheter complications. Results: A total of 104 patients had documentation of 105 epidural catheter placements in the chart; five procedures were unsuccessful in four patients, resulting in 100 successful epidural catheter placements (70 caudal-threaded and 30 direct lumbar/thoracic). Patient and surgical characteristics, postoperative pain and sedation scores, and opioid consumption did not differ significantly between groups. Direct lumbar/thoracic epidural catheter placement required longer procedure times. Patients in the direct lumbar/thoracic epidural group were more likely than those in the caudal-threaded group to receive a ropivacaine/clonidine infusion (47% vs. 4%; p < 0.001) and a programmed intermittent bolus of epidural infusion (60% vs. 3%; p < 0.001). The direct lumbar/thoracic group experienced more postoperative catheter-related complications than the caudal-threaded group (20% vs. 4%; p = 0.02), primarily catheter leakage requiring premature catheter removal. Conclusions: Epidural catheter placement was successful in 96.2% of patients. No statistically significant between-group differences were detected in postoperative pain scores, sedation scores, or opioid consumption between caudal-threaded and direct lumbar/thoracic epidural catheters in small-weight infants (median 3 kg) when placed by a Pediatric Acute Pain Service. Direct lumbar/thoracic epidural catheters were associated with a higher incidence of postoperative catheter leakage and premature catheter removal; however, these complications cannot be attributed solely to the location of epidural catheter insertion. These findings may help clinicians select the most appropriate epidural technique for postoperative pain management in this population.