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

INTRODUCTION: Investigation the association between cerebral oxygenation and short-term adverse outcome in asphyxiated infants with hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH).

METHODS: Near infrared spectroscopic-derived cerebral oxygen saturation (rScO 2) pattern during first 4 days was compared to early brain MRI (4-10 days) using the Weeke score to define MRI-derived brain injury of infants with GA >35 weeks treated with TH within 6 h between 2010 and 2023. 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 ± 1 SD: GA 39.4 ± 1.9 weeks; BW 3,442 ± 621 g; median [IQR] 5-min Apgar score 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 rScO 2 values compared to moderate or mild HIE infants. Mixed model analysis showed an association between rScO 2 (dependent variable), time after birth, adverse short-term outcome, and inhaled nitric oxide. Logistic regression showed that adverse outcome had a positive association with rScO 2 and first lactate levels.

DISCUSSION: 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.