Asad Siddiqui, Andrew Tse, James E Paul, Peter Fitzgerald, Bernice Teh

Managing postoperative pain in patients undergoing minimally invasive pectus excavatum repair (Nuss procedure) is challenging but essential in facilitating ambulation and minimizing the length of stay. Although multiple epidural regimens with varying opioids are presently used for pain management, there is currently no clinical consensus regarding which epidural regimen provides the best analgesia outcomes with the fewest side effects. This 10-year retrospective cohort study was performed to compare the quality of analgesia and the incidence of side effects associated with the three most common epidural regimens used at a tertiary care children's hospital, in patients undergoing the Nuss procedure. Seventy-two pediatric patients were identified as having been treated with one of three epidural regimens for postoperative pain management following the Nuss procedure: Group A (n=12) received 0.125% bupivacaine and 5 µg/mL fentanyl, Group B (n=21) received 0.125% bupivacaine and 10 µg/mL hydromorphone, and Group C (n=39) received 0.1% ropivacaine and 20 µg/mL hydromorphone. Our primary outcome was maximal daily pain scores (numerical rating scale 0-10), with an analytical focus on postoperative day 1 scores. The primary outcome was analyzed using linear regression. The secondary outcomes included the length of stay, side-effect profiles as reflected by the number of treatments for nausea and pruritus, pain scores according to epidural site insertion, occurrence of breakthrough pain, and presence of severe pain throughout their hospital stay. Secondary outcomes were analyzed using linear or logistic regression adjusted for pain scores at baseline. The criterion for statistical significance was set a priori at alpha =0.05. Group A had significantly higher day-1 pain scores (score 5.42/10) than Group B (4.52/10; P=0.030) and Group C (4.49/10; P=0.015) after adjusting for baseline pain and age. No significant difference in maximum daily pain scores was found between groups during postoperative days 2-5. Among secondary outcomes, Group C had a significantly lower incidence of nausea/vomiting than Group B (P=0.003). There was also significantly more severe pain in Group A than in Group C (P=0.031). No significant difference was found between the three groups for the incidence of pruritus, critical events, breakthrough pain, or patient satisfaction. There is no significant difference in managing postoperative pain overall between the three epidural regimens employed at our center. However, in managing day-1 postoperative pain and minimizing nausea/vomiting, our study suggests that a hydromorphone-ropivacaine epidural regimen appears to have more favorable results than a fentanyl-bupivacaine regimen or a hydromorphone-bupivacaine regimen.