Investigation of bleeding disorders

The nature of the defect and therefore the most appropriate initial investigations may be suggested by the history and examination.

 

Vascular / platelet bleeding is suggested by bruising of the skin and bleeding from mucosal membranes.

 

Inherited coagulation disorders are associated with haemarthrosis (bleeding into the joints) and muscle haematomas.

 

Thromocytopenia is the most common cause of abnormal bleeding.

 

¨ Platelet count and blood film—initial investigation

¨ Coagulation tests—abnormal with deficiencies or inhibitor of the clotting factors. Test between these two by adding normal plasma to patient’s plasma.

¨ Prothrombin time (PT) or internationalized normalised ratios (INR) is prolonged with abnormalities of the extrinsic and common pathways of the coagulation cascade.

¨ Partial thromboplastin time with kaolin (APTT) is prolonged with abnormalities of the intrinsic or common pathways.

¨ Thrombin time (TT) is prolonged with fibrinogen deficiency, dysfibrinogenaemia (normal levels, abnormal function), heparin treatment or disseminated intravascular coagulation (DIC).

¨ Bleeding time– abnormal with von Willebrand’s disease, with blood vessel defects and when there is an decrease in the number or function of platelets.

 

These tests will localise the site of the problem. Further specialised investigations may be necessary to identify the exact haemostatic defect correctly.                 

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