[The anemic gap in depressed newborn infants]

Thirty cesarean section-delivered newborn were studied. Fifteen of them scored from 0 to 3 and, 8 and greater on the Apgar scale when measured at one and five minutes, respectively. The other 15 scored 8 or more at one minute and 9 at five minutes. Arterial electrolyte and blood gases were measured in samples obtained from the umbilical cord. The anion gap formula was then applied. The average weight of the depressed newborns was found to be less than for those of the control group. The mean gestational age for both groups was 39 weeks. The average values for electrolyte, bicarbonate and the anion gap were found to be practically the same in both groups. No correlation was found between the pH and the gap nor for the gap and the hydrogen ion concentration [H+]. The correlation between the gap and the bicarbonate was 0.78. No differences were seen between anion gap values for the newborn with lactic acidosis or hyperlactemia when compared to those of the control group. It is therefore concluded that the anion gap is not useful for the detection of newborns suffering from metabolic acidosis. Anion gap; bicarbonate; Apgar score; depressed neonates; metabolic acidosis.