Association between cerebral oxygen saturation and brain injury in neonates receiving therapeutic hypothermia for neonatal encephalopathy.

Objective: To assess the association of cerebral oxygen saturation (CrSO ₂ ) collected by near infrared spectroscopy (NIRS) during therapeutic hypothermia (TH) and rewarming with evidence of brain injury on post-rewarming MRI.
Study Design: This retrospective cohort study included 49 infants, who received TH for mild to severe neonatal encephalopathy. Of those, 26 presented with brain injury assessed by a novel MRI grading system, whereas 23 had normal MRI scans.
Results: CrSO ₂ increased significantly from the first to the second day of TH in infants with brain injury, whereas it remained stable in patients with normal MRI. Increasing mean CrSO ₂ values during rewarming was associated with brain injury (aOR 1.14; 95% CI 1.00-1.28), specifically with gray matter (GM) injury (aOR 1.23; 95% CI 1.02-1.49). The area under the ROC curve showed an excellent discrimination for GM involvement.
Conclusion: Clinically applied NIRS during TH and rewarming can assist in identifying the risk for brain injury.