Automation of routine coagulation testing using a random access centrifugal analyzer

The results are reported of a clinical and laboratory evaluation of the use of a random-access centrifugal analyzer linked to a personal computer in the management of the routine workload of a hemostasis laboratory. Over a three-month period, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin clotting time (TCT), and derived fibrinogen (Fib) were performed on a total of 929 samples. Included in the study were 448 samples from patients receiving anticoagulants (oral anticoagulants, 228; heparin, 166; heparin and warfarin, 130) and 351 samples from patients requiring coagulation screens (PT, APTT, TCT, Fib). Tests were done in parallel with tilt-tube manual techniques and the results correlated. The correlation coefficients were PT, 0.99; TCT, 0.72; APTT, 0.96; Fib, 0.97. Discrepancies were analyzed and were due to hypofibrinogenemia and hyperlipidemia. The poorer correlation coefficient of TCT was attributable both to lower reproducibility of the manual test and the effect of dysfibrinogenemia or FDPs in liver disease. In no case was an abnormality or diagnosis missed using the centrifugal analyzer. In several cases the increased sensitivity of the analyzer improved the detection of the lupus anticoagulant. The use of automation was accompanied by a major reduction in workload and reagent costs. The machine has been used to assay a wide range of coagulation tests by clot based and chromogenic substrate methods. In conclusion, a programmed centrifugal analyzer is a safe, efficient, and flexible way of automating routine coagulation tests. It widens the reportoire of tests performed in the Hemostasis laboratory by using a machine capable of being used in other areas of pathology.