(62) Outcomes of Infants with Non-Perinatal Hypoxic-Ischemic Encephalopathy Treated with Therapeutic Hypothermia or Not: Children's Hospitals Neonatal Consortium Comparative Data

Background: Therapeutic hypothermia (TH) is standard of care for newborn infants with moderate-severe hypoxic-ischemic encephalopathy (HIE) identified in the perinatal period and improves survival without increasing neurodevelopmental impairment. However, trials of TH in older neonates after cardiac arrests have failed to show benefit, likely due to the limited number of neonates included. Recent reports suggest potential benefits of TH for newborn infants who suffered hypoxic injury outside the immediate perinatal period and practice variation exists.

Objectives: To characterize infants with non-perinatal HIE treated with or without TH and their short-term outcomes.

Design/Methods: The Children’s Hospital Neonatal Consortium database was queried to identify infants ≥35 weeks gestationall age (GA) with non-perinatal HIE and admitted within 29 days of birth. Infants were stratified by whether they received TH. Short-term outcomes assessed were length of stay (LOS) and death. Descriptive data are presented, pending statistical analyses.

Results: 235 infants were identified with non-perinatal HIE; 90 (38%) received TH while 145 (62%) did not. Gender and age of infants who did or did not receive TH are shown in Figure 1. Distribution of infants by GA are shown in Figure 2.
Among infants who did not receive TH, 51/145 (35%) were identified on d0, 20/145 (14%) on d1, 42/145 (29%) on d2-7 and 36/145 (25%) between d8-29, respectively. Among infants who received TH, 45/90 (50%) were identified on d0, 13/90 (13%) on d1, 20/90 (22%) on d2-7 and 12/90 (13%) between d8-29, respectively.
For the entire cohort, the neonatal intensive care unit (NICU) mortality was 40%, in-hospital mortality was 49%. Median NICU LOS was 11d; longer in survivors (17d) compared to non-survivors (5d).
For infants who received TH, NICU mortality was 43% and in-hospital mortality was 46%. Median NICU LOS was 13d, with longer LOS in survivors (17d) compared to non-survivors (4d). NICU mortality was 29%, 62%, 50% and 67%, and median LOS for non-survivors was 3, 11, 4, and 7d for infants who received TH on d0, d1, d2-7 and d8-29, respectively.

Conclusion: Over one-third of of infants with non-perinatal HIE were treated with TH, the majority of whom was identified on d0-1. Infants who received TH on d0 had lower NICU and in-hospital mortality rates compared to those identified later. These preliminary findings need to be confirmed further in ongoing analyses.