Safety and efficacy of therapeutic hypothermia in neonates with mild hypoxic-ischemic encephalopathy

Background Though there has been an increase in the number of neonates with hypoxic-ischemic encephalopathy (HIE) treated by therapeutic hypothermia (TH) in recent years, the effect of therapeutic hypothermia on mild HIE neonates is still uncertain. Objectives This study aims to explore the safety and efficacy of therapeutic hypothermia in neonates with mild HIE. Methods Retrospectively collected between January 2010 to December 2022 at Children’s Hospital of Fudan University, neonates with mild HIE were divided into TH and non-TH groups. Clinical data of the mild HIE neonates and their mothers’ general information during pregnancy were collected. SPSS 23.0 was used to compare the general condition, the incidence of adverse events, and efficacy in the two groups. Results A total of 71 neonates with mild HIE were included, including 31 in the TH group and 40 in the non-TH group. Compared with the non-TH group, the TH group had significantly lower 5-minute Apgar scores [6 (5–7) points vs. 7 (5–8) points, p = 0.033 ], but a higher rate of tracheal intubation at birth (68%, 21/31 vs. 40%, 16/40, p = 0.02), a higher rate of chest compressions > 30 s (39%, 12/31 vs. 15%, 6/40, p = 0.023), the later initiation enteral feeding [4 (3–4) days vs. 1 (1–2) days, p < 0.001], a higher usage rate of analgesic and sedative drugs (45%, 14/31 vs. 18%, 7/40, p = 0.011) and the longer hospital stay [12.5 (11–14) days vs. 9 (7-13.9) days, p = 0.003]. There was no death in 71 mild HIE neonates. TH group had lower incidence of brain injury (16%, 5/31 vs. 43%, 17/40, p = 0.017) and encephalopathy progression (10%, 3/31 vs. 45%, 18/40, p = 0.001) than the non-TH group. There was no statistical significance in the incidence of adverse events between the two groups. Conclusion Therapeutic hypothermia can reduce the incidence of brain injury in neonates with mild HIE.