Early Postoperative Intra-Abdominal Pressure and Heart Rate in Relation to Time to Trophic Enteral Feeding After Posterolateral Congenital Diaphragmatic Hernia Repair: An Exploratory Cohort Study

Background: Advances in neonatal intensive care have improved survival in congenital diaphragmatic hernia (CDH), shifting the clinical focus toward long-term complications such as feeding difficulties. Initiation of enteral feeding varies across centers, with evidence suggesting that intra-abdominal pressure (IAP) may influence time to feeding and clinical decision-making. We explored associations of early postoperative heart rate (HR), recorded Apgar score, and intra-abdominal pressure (IAP) with time to enteral trophic feeding. Methods: We retrospectively evaluated 28 consecutive neonates undergoing CDH repair at a national referral center between January 2022 and June 2025. Trophic enteral feeding (≥10 mL/kg/day for ≥24 h) was the primary endpoint. Aalen–Johansen estimates and two parsimonious Fine–Gray models (HR plus Apgar; IAP plus Apgar) were primary analyses and cause-specific Cox models were sensitivity analyses. Results: Within 30 postoperative days, trophic enteral feeding was achieved in 21 cases, six patients died before feeding, and one did not achieve feeding before censoring. Each 10 bpm higher HR was associated with lower feeding incidence (subdistribution HR 0.62, 0.46–0.85; p = 0.003); the cause-specific point estimate was also below 1 (HR 0.65, 0.47–0.89; p = 0.007). Mean IAP was not clearly associated with feeding incidence (subdistribution HR 1.01 per mmHg, 0.82–1.25; p = 0.925). Both Cox models failed global proportional-hazards tests. Conclusions: Each 10 bpm increase in HR was associated with a longer time to trophic enteral feeding, and the cause-specific sensitivity analysis pointed in the same direction. Because both estimates derive from the same 28 infants, their agreement is expected rather than corroborative. These findings are exploratory and do not establish causality, individual predictive value, or superiority of HR over IAP. Prospective multicenter studies with adequate sample sizes are needed to confirm these findings.