Does Early Cerebral Near-Infrared Spectroscopy Monitoring Predict Outcome in Neonates with Hypoxic Ischaemic Encephalopathy? A Systematic Review of Diagnostic Test Accuracy

Abstract

<b><i>Introduction:</i></b> Hypoxic ischaemic encephalopathy (HIE) remains one of the top 10 contributors to the global burden of disease. Early objective biomarkers are required. Near-infrared spectroscopy (NIRS) may provide a valuable insight into cerebral perfusion and metabolism. We aimed to determine whether early NIRS monitoring (<6 h of age) can predict outcome as defined by grade of encephalopathy, brain MRI findings, and/or neurodevelopmental outcome at 1–2 years in infants with HIE. <b><i>Methods:</i></b> We searched PubMed, Scopus, Web of Science, Embase, and The Cochrane Library databases (July 2019). Studies of infants born ≥36<sup>+0</sup> weeks gestation with HIE who had NIRS recording commenced before 6 h of life were included. We planned to provide a narrative of all the studies included, and if similar clinically and methodologically, the results would be pooled in a meta-analysis to determine test accuracy. <b><i>Results:</i></b> Seven studies were included with a combined total of 161 infants. Only 1 study included infants with mild HIE. A range of different oximeters and probes were utilized with varying outcome measures making comparison difficult. Although some studies showed a trend towards higher cSO<sub>2</sub> values before 6 h in infants with adverse neurodevelopmental outcomes, in the majority, this was not significant until beyond 24 h of life. <b><i>Conclusion:</i></b> Very little data currently exists to assess the use of early NIRS to predict outcome in infants with HIE. Further studies using a standardized approach are required before NIRS can be evaluated as a potential objective assessment tool for early identification of at-risk infants.

Evolution of early cerebralNIRSin hypoxic ischaemic encephalopathy

“…Obtaining early data in this cohort is challenging 8 . Only 26 infants were included at 6 h; however, these numbers are similar to previously published studies examining NIRS at this early time point 8 . We do not have a control group, however, data from healthy term controls have been published previously as discussed above.…”

“…Summary measures of cSO 2 and FTOE over time by groupThis study is limited by the small number of infants included particularly in the early time measurements and the varying number of data available at each time point. Obtaining early data in this cohort is challenging 8. Only 26 infants were included at 6 h; however, these numbers are similar to previously published studies examining NIRS at this early time point 8.…”

“…7 However, very few studies have examined the use of NIRS at earlier time points and its evolution over time in the setting of HIE. 8 Furthermore, no study has examined the evolution of cSO 2 in infants with mild HIE. The aim of this study was to describe early cSO 2 and FTOE in infants with all grades of HIE, to examine their evolution over time and determine whether early NIRS values (at 6 and 12 h) are useful in the prediction of MRI outcome and/or death.…”

“…The evolution of values over time is also important as greater magnetic resonance imaging (MRI) injury has been identified in infants with more rapidly increasing cSO 2 7 . However, very few studies have examined the use of NIRS at earlier time points and its evolution over time in the setting of HIE 8 . Furthermore, no study has examined the evolution of cSO 2 in infants with mild HIE.…”

“…Prior 6 When combined with aEEG, improved prediction of abnormal outcome was possible at 12-36 h of age 6. However, few studies have examined the ability of early NIRS to predict outcome 8. We examined the use of NIRS values at 6 and 12 h to predict MRI outcome.…”