Comparative Study Between Intravenous Patient-Controlled Analgesia Morphine and Computerized Ambulatory Delivery Device Epidural Morphine for Post Operative Analgesia for Nuss Procedure in Pectus Excavatum: A Retrospective Analysis

Background: Pectus deformities are commonly seen in chest wall deformities among the pediatric age group. Pectus deformities occur due to defective growth of the sternum and its surrounding cartilage. The Nuss procedure is the technique of choice for correcting the deformity surgically which includes placing a convex bar under the sternum without resection or injury to costal cartilages. Adequate pain control is utmost to improve wound healing, patient satisfaction, short hospital stays, and decrease the financial burden on attendants. Therefore, it is necessary to investigate which analgesic method is more advantageous for the Nuss procedure. Objective: To compare the analgesic effects of intravenous patient-controlled analgesia (IVPCA) morphine versus computerized ambulatory delivery device (CADD) epidural morphine on acute post-operative pain management in Nuss procedures. Methods: A retrospective study was done at Rajiv Gandhi Cancer and Research Hospital, New Delhi from 2015 to 2020 to assess the efficacy and safety between IVPCA morphine and CADD epidural for post-operative analgesia following pectus excavatum repair. A total of 34 cases of Nuss procedures were taken with 17 cases in each group. Group 1 (intravenous PCA morphine) was given 39 ml normal saline + 6 ml morphine (total 45 ml, 2 mg/ml morphine), set at demand dose 0.5 ml, i.e. 1 mg, lockout interval 7 minutes, doses per hour was six and Group 2 (CADD epidural morphine) was given 42 ml normal saline + 3 ml morphine (1 mg/ml morphine) with continuous infusion at the rate of 0.5 ml/hr. Demand dose 0, lockout interval nil. Visual analog pain scores using a scale of 0-10 and Ramsay Sedation Score (RSS) scores were obtained on arrival at the post-anesthesia care unit, at 12, 24, 48, and 72 hours throughout the subsequent hospital stay. Results: This study yielded positive information about our experience with the pectus post-operative pain management. The mean visual analog scale (VAS) score was lower in Group 1 compared to Group 2 but significantly different at 12 and 72 hours only. The mean RSS score was comparable between groups. The mean hospital stay (days) and requirement of rescue analgesia doses were 3.47±0.51 and 0.12±0.33 in Group 1 and 4.76±0.44, 0.59±1.12 in Group 2. Conclusion: Both IVPCA morphine and CADD morphine were effective in controlling post-surgical pain in the Nuss procedure, but IVPCA morphine was better as compared to CADD morphine in this regard because it was noninvasive, safe, and cost-effective with non-significant complications.