Assessment of the haemostatic status of individual patients begins with a full and adequate medical history and physical examination. It is often followed (sometimes inappropriately) by the ordering of coagulation screening tests such as the PT (Prothrombin Time) and APTT (Activated Partial Thromboplastin Time). While normal results, coincident with negative history is often sufficient to exclude a significant haemostatic dysfunction, and, whilst abnormal results coincident with positive history may provide clues for specific follow up, difficulties may arise when an unexpected result is obtained. Consequently, a patient with a negative clinical history may give an abnormal coagulation result upon testing. Similarly, whilst a patient with a positive clinical history may yield an abnormal coagulation result following testing, a normal result is commonly obtained. The laboratory follow up of these scenarios usually involves a sequence of simple procedures, selected to both exclude certain alternatives, and to guide further investigation. Central to this process is the performance of additional simple screening tests, and/or mixing studies. The clotting time result of a mixture of test plasma (originally abnormal) with plasma from normal individuals gives valuable information regarding the probable nature of the defect in the test plasma sample, and therefore which additional tests may be required to delineate specific defects. The following report attempts to summarise potential coagulation laboratory scenarios, and suggested procedures for follow-up of unexpected or abnormal coagulation results.
|Number of pages||7|
|Journal||Australian Journal of Medical Science|
|Publication status||Published - 1994|