ABSTRACT
The bleeding time is defined as the time between the infliction of a standard incision and the moment at which bleeding stops, i.e. when a platelet plug forms. The most reliable method uses a spring-loaded blade to inflict one or two standard incisions on the volar surface of the forearm while a blood pressure cuff is inflated around the upper arm to 40 mmHg. The incision is dabbed with filter paper every 30 s until the
I Fibrinogen
II Prothrombin
III Tissue thromboplastin
IV Calcium ions
V Proaccelerin, accelerator globulin, prothrombokinase
VI An unused number
VII Prothrombinogen, serum prothrombin conversion accelerator (SPCA)
VIII Antihaemophilic factor
IX Christmas factor
X Stuart or Stuart-Prower factor
XI Plasma thromboplastin antecedent
XII Hageman factor or glass factor
XIII Fibrin or clot-stabilizing factor
bleeding stops. A normal value lies between 2 and 9 min. The test does, however, suffer from poor reliability and reproducibility, and is of questionable value other than as a gross indicator of platelet effectiveness.
