Evaluation of the SonoClot Analyzer for the measurement of platelet function in whole blood.

A viscoelastometer, the SonoClot Coagulation Analyzer, has been proposed for use in the evaluation of platelet function. The purpose of this study was to evaluate systematically this instrument when used with whole blood. Under laboratory conditions, the coefficient of variation (cv) of determinations of whole blood activated clotting time (ACT) on the instrument was approximately 7.0 percent. In contrast, the cv of measurements on whole blood related to the graphic events associated with clot formation ranged from 9.2 to 41.7 percent. Because of the large and variable cvs associated with these measurements of clotting, the SonoClot Analyzer cannot presently be recommended for use in studies designed to examine quantitatively the clotting function in whole blood.