Criteria for the AT III substitution were fulfilled by 33 infants. Mean birth weight was 1321 g (480 g up to 2860 g), and mean gestational age was 29 weeks (23-39 weeks).
AT III substitution in dosing of 5 u/kg/hr was administered to all patients as well as standard heparin 10 u/kg/hr. Initial plasma level of AT III in the study group prior to start of the substitution was 45 +/- 17% activity of normal plasma of adult donor.
The value increased up to 90 +/- 32% after 24 hours and up to 113 +/- 38% at the end of the therapy. Eight patients died (24%).
Considerable decrease of the Neonatal Therapeutic Intervention Scoring System (NTISS), indicating a level of multiple organ dysfunction, was observed as early as after the first 48 hours of AT III therapy in the entire group (p < 0.01). Extensive increase of platelet count (p < 0.05) occurred after 48 hours of AT III therapy in survivors.
Except for a severe sepsis in one case, no clinical signs of increased bleeding occurred during the AT III therapy, and the clinical signs of pre-existing bleeding even disappeared in 5 cases. Analysis of the group of 8 deceased patients revealed irreversible organ dysfunction in 7 cases present prior to the start of AT III substitution.
In conclusion, during the AT III substitution, no bleeding, no clinical side effects but improvement in multiple organ dysfunction including increase in platelet count was recorded.