ANION GAP IN MECHANICALLY VENTILATED NEWBORN-INFANTS WITHIN THE FIRSTWEEK OF LIFE

In 410 consecutively admitted mechanically ventilated neonates (gestat ional age, 34.8 +/- 4.0 weeks', birthweight, 1930 +/- 890 g) anion gap [(Na + K) - (HCO3 + Cl)] was calculated at admission to the neonatal intensive care unit. Within their first week of life, 47 neonates died and 113 neonates were extubated; in the remaining 250 neonates anion gap was also calculated at day 7. Despite a statistically significant lower anion gap in survivors than in nonsurvivors (P <0.05), an elevat ed anion gap was clinically no predictor of mortality either at the da y of admission (22.7 vs 25.3 mmol/L) or after the first week of life ( 20.3 vs 23.2 mmol/L). Mechanically ventilated neonates exhibited durin g their first week of life a much larger anion gap than critically ill adults in recent studies. The individual critically ill newborn might be too frequently subject to metabolic disturbances as detected by an ion gap to allow any prognostic information.