1423 PLATELET DYSFUNCTION: AN ETIOLOGIC FACTOR IN INTRAVENTRICULAR HEMORRHAGE (IVH) IN THE PREMATURE

Abstract

Serial platelet counts, bleeding times, in vitro platelet aggregations, prothrombin times (PT), partial thromboplastin times (PTT), fibrinogens, and fibrin degradation products (FDP) were performed in 58 prematures ≤1500 grams to show the relationship of platelet and clotting disorders to IVH. IVH was detected by CT scan, real-time ultrasonography and/or autopsy. 17 had no intra-cranial hemorrhage (ICH), 11 had subarachnoid hemorrhage (SAH) only, and 30 had intraventricular hemorrhage (IVH). 12 died (2 SAH and 10 IVH). Mean Day 1 platelet counts were normal in all 3 groups. Initial platelet counts were ≥150,000/mm3 in 26 of 30 infants who developed IVH, but by day 7 thrombocytopenia occurred in 14 (47%). Platelet dysfunction, however, was evident on day 1 in the group with IVH. Day 1 bleeding times were significantly longer (p<.02) in infants who developed IVH (6 min±0.6; × ± SEM) than in those without ICH (3.7±0.9). Maximum platelet aggregations to adenosine diphosphate (ADP) were significantly lower (p<.025) on day 1 in IVH infants (41.5%±4) than in those without ICH (55.4%±4). By day 3, bleeding times deteriorated (p<.05) in IVH infants while aggregations were similar to day 1. Initial PT's and/or PTT's were abnormal in 16/30 infants with IVH in contrast to 2/28 infants with SAH or no ICH (p<.05). Normal fibrinogens and negative FDP's ruled out DIC in all but 3 cases of IVH. These data suggest that platelet dysfunction as well as coagulation defects may predispose the premature infant to IVH.