355 - Short-Term Outcomes of Neonates with Hypoxic-Ischemic Encephalopathy Receiving Active Versus Passive Cooling During Transport

Poster Number: 355
Publication Number: 355.443

Ashleigh Manktelow, Creighton University School of Medicine, Omaha, NE, United States; Elizabeth Lyden, University of Nebraska Medical Center, Omaha, NE, United States; Eric S. Peeples, University of Nebraska Medical Center/Children's Hospital & Medical Center, 8200 Dodge Street, NE, United States

Background: The only treatment for neonatal hypoxic-ischemic encephalopathy (HIE) is therapeutic hypothermia (TH), which must be started within 6 hours to be effective. The narrow therapeutic window and lack of resources to perform TH in many hospitals mean that TH must often be initiated prior to or during transport to the referral hospital. Passive TH may result in over- or under-cooling, so servo-controlled devices are often used to better achieve and maintain goal temperatures in transport; however, the effects of this improved temperature regulation on short-term outcomes has not been thoroughly evaluated.

Objective: To assess the effects of active servo-controlled TH in transport on short-term outcomes – including brain injury on magnetic resonance imaging (MRI) – in newborns with HIE.

Design/Methods: A single-center retrospective cohort study of infants with HIE treated with TH from 2012-2020. Exclusion criteria were infants born at < 35 weeks gestation age or with other brain anomalies. Demographics, temperatures in transport and on arrival, and short-term outcomes were abstracted from the medical record. Mann Whitney U test was used to compare continuous variables and Fisher’s exact test for categorical variables.

Results: Seventy-six infants were included: 13 active and 63 passive TH. There were no differences in demographics, initial pH or base, initial resuscitation, or HIE severity between groups (Table 1). Significantly more infants arrived within goal temperature range in the active group (69% versus 30%, p=0.036), but there were no differences in incidence of seizures, need for vasoactive infusions, complications of TH, need for gavage feeds at discharge, survival to discharge, or duration of invasive or total respiratory support. Infants in the active TH group, however, had significantly more brain injury on MRI (92% vs. 59%, p = 0.045); specifically deep grey matter injury (58% vs. 24%, p=0.033).Conclusion(s): In our cohort, active TH resulted in more infants arriving within goal temperature, but those infants did not demonstrate improved short-term outcomes, and, in fact, had a higher incidence of brain injury on MRI. Unfortunately, the active TH group was too small to adjust for other variables, though there were no differences in demographics or metrics of disease severity on univariate analyses. Future studies are needed to confirm these findings in a larger cohort and to assess the longer-term developmental outcomes between these two practices.
Table 1Demographic, early severity, and short-term outcome data, stratified by receipt of active or passive therapeutic hypothermia, categorical presented as n (%) and continuous as mean ± SD.