PREDICTIVE VALUE OF LOW AT III LEVELS FOR THE OCCURRENCE OF IVH, IRDS AND DEATH IN PREMATURE NEONATES

Abstract

The observation of AT III deficiency in premature neonates with Idiopathic Respiratory Distress Syndrome (IRDS), suggests a positive predictive value for a poor outcome. The underlying diffuse intravascular coagulation could generate serious hemorrhagic complications like Peri/Intraventricular Hemorrhage (IVH).A prospective study was performed in consecutively born neonates to assess the predictive value of low AT III for theoccurrence of IVH, (gr. III/IV), IRDS, and death. Eighty-one neonates were included in the study during a period of 5 months. AT III levels were determined immediately after birth by a chromogenic substrate assay. Values in umbilical cord blood were identical with values in capillary or peripheral vein blood samples taken within 6 hours after birth. There was no correlation between AT III values and gestational age (r: 0.18). Twenty-four neonates with IRDS showed a mean AT III value of 0.23 U/ml (S. D. ± 0.07 U/ml) which was significantly lower than a mean AT III value of 0.35 U/ml (S. D. ± 0.1 U/ml) for neonates without IRDS (p ≺0.00005). When IVH gr. III/IV was diagnosed in neonates having IRDS (8/24) no significant difference in mean AT IIIact was observed with respect to jnean AT III levels of remaining neonates without this complication. No death occurred in neonates without IRDS. Mean AT IIIact (0.21 U/ml) in neonates with IRDS who died (9/24) was low compared with mean AT III levels of neonates with IRDS who survived (0.25 U/ml), but did not reach significance (p≻0.1). Assuming a critical value of AT III of 20% a positive predictive value of 89% for IRDS, 44% for IVH, and 56% for death was calculated. It is concluded that low AT Illact levels have a high predictive value for IRDS.