475 - Physiologic Stability During Transport and Clinical Outcomes for Infants with Congenital Diaphragmatic Hernia

Publication Number: 475.6225

Katrin Lichtsinn, Seattle Children's, Seattle, WA, United States; Daniel A. Enquobahrie, University of Washington, Seattle, WA, United States; John Feltner, University of Washington School of Medicine, Seattle, WA, United States; Megan Gray, University of Washington School of Medicine, Seattle, WA, United States; Rachel A.. Umoren, University of Washington, Seattle, WA, United States; Zeenia Billimoria, University of Washington School of Medicine, Seattle, WA, United States

Background: Many infants with congenital diaphragmatic hernia (CDH) are transferred after birth to a level IV neonatal intensive care unit (NICU), with transfer urgency based on predicted CDH severity. The Transport Risk Index of Physiologic Stability (TRIPS) score is a validated tool that assesses neonatal transport risk based on four components: temperature, blood pressure, respiratory status, and response to noxious stimuli, and correlates with NICU morbidity and mortality.

Objective: Determine the association between pre-transport TRIPS score, clinical outcomes, and transport times in infants with CDH.

Design/Methods: Retrospective study of infants with prenatally diagnosed CDH transported by a pediatric critical care team to a regional Level IV NICU from 2020-2024. Chart-based demographic and clinical data, including transport vital signs and transport times were used. Infants were categorized based on TRIPS scores: low (0-16), medium (17-23), and high (24+). CDH severity was determined based on observed to expected total fetal lung volume (O/E TFLV) on prenatal MRI or observed to expected lung to head ratio (O/E LHR) by ultrasound: mild (≥35%), moderate (25-34%), or severe ( < 25%). Vital sign abnormalities were defined using clinical standards. Outcomes of interest included survival to discharge, length of hospital stay, extracorporeal membrane oxygenation (ECMO) use, intra-transport vital sign abnormality, and timing of transport milestones. Kruskal-Wallis or Fisher’s exact tests were used to compare clinical characteristics and outcomes across TRIPS score categories.

Results: 51 infants were included; 33 (65%) with low, 13 (25%) with medium, and 5 (10%) with high TRIPS scores. CDH severity increased with higher TRIPS score category (p=0.01, Table 1). Rate of ECMO use varied by TRIPS score (100% for high, 38% for medium, 21% for low; p=0.001). There was no significant difference in survival to discharge or hospital days across TRIPS score groups. More infants with high scores received vasopressors or saline boluses and had shorter birth to transfer of care time and time at the referring facility (Table 2). Compared with those with low and medium TRIPS scores, more infants with high TRIPS scores had temperature instability (p=0.004, Table 3).

Conclusion(s): Pre-transport TRIPS score correlated with CDH severity, ECMO use, and faster transport, but not survival or hospital stay. Temperature instability was observed more frequently among infants with high TRIPS scores. These findings support the consistent use of TRIPS scores in this patient population and underscore the need for thermal support during transport.

Table 1. Demographics and hospital course variables for infants with CDH stratified by TRIPS score.
Data is represented as median [IQR] or count (%). Asterisks (*) denote results with statistical significance (p < 0.05).

Table 2. Transport characteristics for infants with CDH stratified by TRIPS score.
Data is represented as median [IQR] or count (%). Asterisks (*) denote results with statistical significance (p < 0.05).

Table 3. Number of infants in each TRIPS score group with at least one abnormal vital sign.
Appropriate ranges listed below each vital sign variable; any value outside of these ranges was considered abnormal. Data is represented as count (%). A single asterisk (*) denotes results with statistical significance (p < 0.05). **Oxygen saturation data removed for infants with cardiac lesions: n=6 removed from low TRIPS score group, n=2 removed from medium TRIPS score group, n=2 removed from high TRIPS score group.