Role of Near-Infrared Spectroscopy in Monitoring the Clinical Course of Asphyxiated Neonates Treated with Hypothermia

Abstract

Objective: Hypoxic-ischemic encephalopathy (HIE) affects millions of newborns annually, especially in low-resource settings. Real-time monitoring of hypoxic-ischemic brain damage is urgently needed for assessment of severity and management of neonates with birth asphyxia. Aim of the work is monitoring of near-infrared spectroscopy (NIRS)-measured cerebral regional oxygen saturation (cRSO₂₎ and cerebral fractional tissue oxygen extraction (FTOE) in neonates after birth asphyxia in relation to their clinical course.

Study design: Forty asphyxiated-term and near-term neonates with mild to severe HIE admitted at neonatal intensive care unit of Alexandria University Maternity Hospital from March to October 2019, received therapeutic hypothermia (TH) and had continuous NIRS monitoring of cRSO₂ for 72 hours. Infants were categorized into HIE with seizing and nonseizing groups, and abnormal and normal magnetic resonance imaging (MRI) groups.

Results: Clinical seizures (CS) occurred in 15 (37.5%) of HIE neonates and 13.3% of them died (n = 2). In the current study, significantly higher cRSO₂ and lower FTOE values were found in the seizing infants as compared with nonseizing group (p < 0.001). NIRS-measured day 2-cRSO₂ and day 1-FTOE were associated with CS in newborns with HIE and day 1-cRSO₂ and FTOE were associated with abnormal MRI at 1 month of age. cRSO₂ values were found to correlate positively with initial Thompson score especially in days 1 and 2. Further, neonates with CS were more likely to have MRI abnormalities at follow-up.

Conclusion: NIRS measures may highlight differences between asphyxiated neonates who develop CS or later MRI abnormalities and those who do not.

Key points: · Day 1 FTOE is the early and sensitive predictor for both clinical seizures and abnormal MRI.. · Cerebral oxygenation metrics help in selecting patients in urgent need of an early MRI scan.. · Cerebral oxygenation metrics can be used hand in hand with clinical assessment using Thompson score at admission to select patient candidate for therapeutic hypothermia..