Cerebral oxygenation and brain activity after perinatal asphyxia: does hypothermia change their prognostic value?

Abstract

Background:Hypothermia is an established therapy in term neonates to reduce death and disability after perinatal asphyxia. Near-infrared spectroscopy-monitored regional cerebral oxygen saturation (rScO 2 ) and amplitude-integrated electroencephalogram (aEEG)-monitored background pattern have been shown to be early predictors of long-term neurodevelopmental outcome. The aim of this study was to investigate the prognostic value of rScO 2 and aEEG for neurodevelopmental outcome in neonates with hypoxic-ischemic encephalopathy (HIE) treated with hypothermia. Methods: In neonates with HIE who were subjected to hypothermia, the aEEG background pattern and rScO 2 were studied prospectively from admission up to 84 h in relation to early magnetic resonance imaging and neurodevelopmental outcome at 18 mo of age. results: Of 39 infants, 12 neonates died because of neurological deterioration. One had an adverse outcome and 26 had a favorable outcome. The rScO 2 was higher in neonates with adverse outcome, although aEEG scores were lower. Positive predictive values at 12, 24, and 36 h of age for adverse outcome ranged from 50 to 67% for rScO 2 and aEEG; negative predictive values ranged from 73 to 96% for rScO 2 and 90 to 100% for aEEG. Combining rScO 2 and aEEG increased positive predictive values (70-91%) and negative predictive values (90-100%). conclusion: During hypothermia, rScO 2 and aEEG measurements are early predictors of long-term outcome after HIE. Combining both parameters further improves early prediction.

Limited short-term prognostic utility of cerebral NIRS during neonatal therapeutic hypothermia

“…The Dutch data demonstrated divergent cerebral rSO 2 and fractional cerebral tissue oxygen extraction values in the first 36 hours of life for those with adverse vs favorable outcome. 4 However, the absolute differences decreased thereafter, with no significant difference at 60 hours, the timeframe most comparable to our study. Therefore, the combination of their and our data suggests that cerebral rSO 2 on the third day of life may not differentiate those destined for favorable or adverse outcomes.…”

“…4 In most ictal recordings of SUDEP, PGES appears to be an EEG hallmark preceding cardiorespiratory arrest. 5 Its mechanism is unclear, yet we believe that the value of PGES as a SUDEP risk marker is more complex than suggested by Dr. Sethi.…”

“…The range of rSO 2 s during hypothermia in asphyxiated infants with adverse outcome measured with the small adult sensor of Somanetics (Troy, MI) is between 82% and 95%. [2][3][4] The highest value of rSO 2 is limited at 95% (set by manufacturer). Since the neonatal sensor of Somanetics read rSO 2 values 10% higher on average compared to the small adult Somasensor, 5 this range has been compressed to between 92% and 95%.…”

Impaired cerebral autoregulation and brain injury in newborns with hypoxic-ischemic encephalopathy treated with hypothermia

“…More recently, NIRS has emerged as an alternative method to interrogate CBF continuously and noninvasively at the bedside (Edwards et al 1988;Skov et al 1991). While prior studies have linked NIRS measures with outcomes in HIE (Ancora et al 2013;Lemmers et al 2013;Meek et al 1999;Toet et al 2006;van Bel et al 1993;Zaramella et al 2007), few studies have focused on evaluating the relationship between MAP and NIRS as a method to interrogate autoregulation (Howlett et al 2013;Tekes et al 2015). Signs of impaired cerebral pressure autoregulation may precede the presence of unregulated CBF, giving this approach the potential advantage of directing intervention before irreversible injury has occurred.…”

Lactate as an early predictor of psychomotor development in neonates with asphyxia receiving therapeutic hypothermia

“…Recently, work has been done to measure localized brain saturation in asphyxiated newborns during TH. Near-infrared spectroscopy (NIRS) appears to be a valuable non-invasive method, which, taken together with the current aEEG, fulfills a valuable role as an early predictor of the long-term outcome 13 . All these predictors are key to how well we are informed regarding current treatment effectiveness, which in turn enables us to provide the most timely and objective information possible to parents during this extremely stressful situation.…”