Rapid microanalysis of coagulation parameters by automated chromogenic substrated methods - application in neonatal patients.

Daily monitoring of coagulation parameters in critically ill premature born neonates is only possible on small amounts of blood obtained by heelpuncture. Therefore, automated spectrophotometric micro-assays for antithrombin III (AT III), factors II and X, plasminogen and alpha 2 antiplasmin were applied on capillary and venous blood samples concurrently obtained in adults and healthy neonates. No statistically significant difference for any of the parameters was revealed. High levels of platelet factor 4 present in serial capillary samples of adults, did not interfere with the heparin dependent AT III assay. There was no evidence of thrombin or thromboplastin generation in these capillary samples, when examined for Va or VII activities. The levels of AT III, factors II and X and of plasminogen in neonates were 35-45% of the adult levels, in contrast to alpha 2 antiplasmin which was in the adult range.