Role of score for neonatal acute physiology (SNAP) in predicting neonatal mortality

To assess the validity of SNAP in predicting the outcome in terms of mortality and duration of hospital stay. The study was also undertaken to evolve the best cut-off SNAP scores for predicting mortality in different individual neonatal conditions.

295 consecutive newborn admitted to NICU during an eleven month period were evaluated with the investigations required as per the specifications of SNAP. Neonates who succumbed within 24 hours of admission and those who were shifted to the NICU for observation purposes were excluded.

In general, SNAP correlated well with mortality; the sensitivity and specificity of SNAP score > 15 in predicting mortality were 63% and 95% respectively. The positive and negative predictive values were 72% and 92.5% respectively. Very low birth weight babies and ventilated preterm neonates had higher mortality and the best cut-off SNAP score for predicting mortality in these groups was 10. In all the other groups, SNAP score > 15 correlated well with higher mortality. By using multiple regression analysis on three variables including birth weight, gestational age and SNAP, SNAP was found to show the best correlation with mortality. On correlating SNAP with duration of hospital stay, 76.8% of the surviving neonates with SNAP < 16 stayed for < 15 days, whereas the rest stayed longer despite low SNAP. All the 9 babies with SNAP > 15 who survived stayed for > 15 days.

SNAP is a measure of illness severity and correlates well with neonatal mortality. SNAP may assist the clinician in explaining the probable outcome and therapeutic intervention needed and the cost of treatment to the parents. SNAP scores > 10 in VLBW babies and > 15 in others are associated with higher mortality.