26 - Impact of Mild Hypoxic Ischemic Encephalopathy (HIE) on In-hospital Outcomes in Neonates

Publication Number: 1023.26

Erin K. Zinkhan, University of Utah School of Medicine, Salt Lake City, UT, United States; Stephen D. Minton, Intermountain Health, Provo, UT, United States; Julie Martinez, Intermountain Health, Murray, UT, United States; Tara L. DuPont, University of Utah School of Medicine, Salt Lake City, UT, United States

Background: Mild hypoxic-ischemic encephalopathy (HIE) increases the risk of neurodevelopmental delay long-term. However, the short-term in-hospital outcomes of newborns with mild HIE who are born outside of a cooling center remains unknown.

Objective: To evaluate the in-hospital outcomes of newborns with mild HIE who are born outside of a cooling center.

Design/Methods: From September 2022 to September 2024, newborns in level 1 and 2 nurseries in the Intermountain Health hospital system were identified as having mild HIE per Prospective Research in Infants with Mild Encephalopathy (PRIME) criteria. Sarnat exams were performed by either in-hospital advanced practice providers or neonatologists, or telehealth neonatologists. In-hospital outcomes, including serial Sarnat exam results, medical complications, reason for transfer if required, and time to discharge were measured.

Results: A total of 42 newborns with mild HIE were identified. The average qualifying gas pH was 7.03 and base deficit was -15.7. The average 1-minute Apgar was 4, 5-minute Apgar was 6, and 10-minute Apgar was 6. A second Sarnat was done on 32 (76%) newborns. Of these 32 newborns, 21 (65%) exams were normal, 8 (25%) continued to show mild HIE, 4 (13%) had progressed to moderate HIE, and one newborn developed seizures within 6 hours. A third Sarnat was done on 8 (25%) newborns, of which 3 (38%) exams were normal, and 5 (63%) showed 1-2 abnormal Sarnat categories. A total of 16 (38%) babies were transferred for moderate HIE requiring therapeutic hypothermia, seizures, or persistent respiratory support needs (see Flow Diagram, differentiated by birth hospital nursery level). Of the 37 newborns who did not progress to moderate-severe HIE, in-hospital complications included hypoglycemia (19%), need for NG feedings or IV fluids (51%), need for respiratory support beyond a 6-hour transition (67%). Of the 26 babies who remained at the birth hospital, the average length of stay was 6.3 days. A routine newborn course was seen in 7 (27%) with discharge in the anticipated timeframe of 2-4 days for mode of delivery in 14 (54%). One newborn with mild HIE had a normal head ultrasound, and two had an MRI, one with extensive diffusion restriction in the cortex, and one was normal.

Conclusion(s): For newborns with mild HIE, persistently abnormal Sarnat exams, hypoglycemia, feeding difficulties, need for respiratory support, and prolonged length of stay is common. Our findings suggest that newborns with mild HIE require close in-hospital monitoring for complications of mild HIE.

Flow diagram of outcomes for infants born in level 1 and 2 nurseries with perinatal acidemia