Cerebral oxygenation pattern during therapeutic hypothermia after perinatal asphyxia: a single center cohort study

Objective: Investigation association between cerebral oxygenation and short-term adverse outcome in asphyxiated infants with hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH). Study design: NIRS-derived cerebral oxygen saturation (rScO2) pattern during first 4 days was compared to early brain MRI (4-10 d) using the Weeke score to define MRI-derived brain injury of infants with GA >35w between 2010 and 2023, on cooling within 6 h. Weeke scores of > 9 were considered adverse short-term outcome. Infants with congenital abnormalities, chromosomal disorders or on ECMO were excluded. Results: 292 infants (mean ± 1sd: GA 39.4 ± 1.9 wks.; BW 3442 ± 621 g; medium [IQR] Apgar score at 5 min 4 [3]) were eligible. According to the Sarnat staging, HIE was mild, moderate or severe in 77, 148 and 67 infants. Adverse short-term outcome/death occurred in 0, 39 (26.4%) and 67 (100%) infants in mild, moderate and severe HIE groups. Severe HIE infants had higher rScO2 values compared to moderate or mild HIE infants. Mixed model analysis showed an association between rScO2 (dependent variable), time after birth, adverse short-term outcome, and inhaled nitric oxide. Logistic regression showed that adverse outcome had a positive association with rScO2 and first lactate levels. Conclusions: High cerebral oxygen saturation during TH is associated with adverse short- term outcome. This knowledge may contribute to early counseling and decision-making. Combination with early blood lactate levels strengthened this association. Simultaneous NO-ventilation may confound this association.