[Prognostic value of near-infrared spectroscopy in hypoxic-ischaemic encephalopathy]

Despite treatment with hypothermia, 40% of newborns with hypoxic-ischaemic encephalopathy die or suffer moderate to severe disability. Near-infrared spectroscopy (NIRS) could be a useful, non-invasive tool to establish the prognosis.

To evaluate the prognostic value of NIRS in predicting neurodevelopmental outcomes at 18 to 36 months in newborns with hypoxic-ischaemic encephalopathy, and to establish the time points and cut-off values of regional cerebral oxygen saturation that exhibit the strongest correlation to these outcomes.

The study included all term newborns with hypoxic-ischaemic encephalopathy managed with hypothermia and NIRS between 2013 and 2016. We established 3 outcome categories: normal neurodevelopment, moderate disability and severe disability.

The sample comprised 28 newborns (median gestational age, 39 weeks; median birth weight, 3195g). The median regional cerebral oxygen saturation increased from 65% to 85% at 48hours post birth. Neurodevelopmental outcomes were normal in 28.6%, while 35.7% developed moderate disability and 35.7% severe disability; 3 patients died. We found a statistically significant difference between groups at 48hours (P=.005) and after hypothermia (P=.03), with higher values in patients with disability. When we compared patients in the severe disability group with the other groups, we found a statistically significant area under the ROC curve at 48hours of 0.872 (P=.001) applying a regional cerebral oxygen saturation cutoff of 83.5%. After hypothermia, regional cerebral oxygen saturation values below 66.0% (AUC, 0.794; P=.017) predicted normal development, while values above 82% (AUC, 0.881; P=.001) predicted severe disability.

NIRS seems to be a valuable tool to predict neurodevelopmental outcomes in patients with hypoxic-ischaemic encephalopathy, even after hypothermia, with higher cerebral oxygen saturation values in patients with disability.