[Evaluation of the STA-R analyzer for the study of neonatal and pediatric hemostasis]

To evaluate the capacities of adaptation of the STA-R analyzer (Diagnostica Stago, Asnieres, France) to the study of pediatric hemostasis, classical studies were undertaken and they have included: (1) Within-run assays (n = 21, 2 control levels) and day-to-day precision studies (n = 20, 2 control levels) for the following tests: prothrombin time (PT), activated partial thromboplastin time (APTT), factor II (FII), factor VII + X (FVII + X), factor V (FV), fibrinogen (fg) and antithrombin (AT); (2) Comparison of the results of APTT, FII, FVII + X, FV and fg assays (in 50 plasmas) obtained with STA-R and STA (analyzer currently used, in our pediatric laboratory). Specific pediatric evaluation has included: (1) Evaluation of the STA-R results for low concentrations of the coagulation factors; (2) Determination of the lowest dead volume; (3) Introduction of peculiar samples among "routine" series. The results showed that within-run assays and day-to-day precision studies have confirmed the good performances of the STA-R. The comparison of the STA-R and STA results from 50 plasmas shows a correlation coefficient of 0.990, 0.995, 0.996, 0.997 and 0.996 for APTT, fg, FII, FVII + V and FV respectively. Such results are confirmed for low concentrations of coagulation factors. The acceptable dead volume could be lowered down to 50 microliters. Very small samples, selected assays and emergencies could be easily introduced among routine series. It is concluded that the STA-R showed very good technical performances. The STA-R is adapted to the routine tests as well as to the very specific samples of neonates and children.