The usefulness of early ultrasonography, electroencephalography and clinical parameters in predicting adverse outcomes in asphyxiated term infants.

Introduction: The early identification of asphyxiated infants at high risk of adverse outcomes and the early selection of those who might benefit from neuroprotective therapies are required. A prospective observational study was conducted to determine if there were any early clinical, neuroimaging or neurophysiological parameters that might predict the outcome in term newborns with asphyxia.

Methods: 44 term newborns with acute asphyxia had a cranial ultrasonography (US), electroencephalography (EEG) and clinical examination performed between three and eight hours of life to determine the parameters that might predict outcome. US findings were classified as normal or abnormal (ventricular dilatation or compression and/or focal/diffuse echogenicities). EEG background activity was classified into two categories: normal/mildly abnormal/intermediate, or severely abnormal (low voltage activity or "suppression-burst"). An intrapartum score (based on graded abnormalities of foetal heart monitoring, umbilical arterial base deficit and five-minute Apgar score) and a hypoxic ischaemic encephalopathy (HIE) score (based on graded abnormalities of the neurological and respiratory status at 3-8 hours of life) was also obtained.

Results: At one year of life, eight infants had died, six had defaulted follow-up, five had major impairment, two minor impairment and 23 were normal. On univariate analysis, poor outcome (death or major impairment) was associated with abnormal cranial US, severely abnormal EEG and a high HIE score (greater than or equal to 15). The positive predictive value was 54.5, 100 and 100 percent, respectively, while the negative predictive value was 93.8, 80.6 and 80.6 percent, respectively. Combining these factors did not improve the predictive values.

Conclusion: There was no added advantage in combining EEG or US parameters over a clinical neurological scoring system alone in predicting the outcome of asphyxiated term newborns.