The logistic score: a criterion for hypothermia after perinatal asphyxia?

OBJECTIVE

To identify during the first hour of life the asphyxiated term neonates who further develop moderate or severe neonatal encephalopathy.

METHODS

In 75 asphyxiated term infants, we measured postnatal arterial base deficit (BD30), assigned an early neurological score (ENS) according to their level of consciousness, respiration pattern and neonatal reflexes at 30 min of life and calculated the logistic score (LS) = (0.33 x BD30) - ENS. The receiver operating characteristics (ROC) methodology was applied to analyze the ability of the LS to correctly classify patients into two groups: normal or mild encephalopathy (60 patients) versus moderate or severe encephalopathy (15 patients).

RESULTS

The area under the ROC curve of the LS for moderate or severe encephalopathy (+/- standard error) was 94.4 +/- 3.6%. At the threshold value of 1.2, the LS provided 87.5% sensitivity and 73.7% positive predictive value (PPV). The PPV of LS reaches 100% for a value >3.2, but this threshold allowed only 53.3% sensitivity.

CONCLUSIONS

The LS is predictive of the neonatal neurological evolution after birth asphyxia and may help to select the high risk patients who are potential candidates for hypothermia therapy.