Clinical Considerations In Primary Hemorraghic Disorders And Hemostasis
A General Overview
In general, primary hemorrhagic disorders are rare, in majority of cases, abnormal bleeding is due to secondary causes, either localized (surgical conditions) or generalized, e.g, hepatic failure, renal failure, anticoagulant overdose, etc. In any patient who gives a history of easy bruising or excessive bledding from childhood, a congenital hemostatic defect is likely. The acquired form starts at a later stage.
Congenital hemorrhagic disorders are characterized by:
- Ecchymosis, hematoma or spontaneous bleeding from multiple sites of following minor trauma.
- Excessive bleeding after trauma or minor surgery.
- Bleeding into joints, gums and mucous membranes of the gastrointestinal and the genitor-urinary tracts.
- History of previous episodes of hospitalization and blood transfusions to control the hemorrhage.
- Abnormality involving one or only a few coagulant factors.
On the other hand, acquired hemorrhagic tendencies set in at a later age may be temporary and may reveal deficiencies of multiple coagulation factors.
Palpable Purpuric Lesions
Classification of hemorrhagic disorders
Broadly, the hemorrhagic disorders can be divided into two undermentioned groups
Purpuric disorders: These effect the process of primary hemostasis, i.e. platelet and/or vascular functions are abnormal. These are characterized by bruising, ecchymosis and bleeding from mucous membranes, especially of the gastrointestinal and genitor-urinary tracts. Bleeding starts soon after injury and it is brisk initially. It is relieved by local pressure. The capillary resistance test (Hess test) is positive. Bleeding time is prolonged. Unless there is severe thrombocytopenia (less than 10000/cmm), coagulation time is not prolonged.
Coagulation defects: These may be congenital or acquired. In majority of cases, the primary coagulation disorders are congenital. They are characterized by deep tissue bleeding, into joints, progressive deformity of joints, prolonged coagulation time and normal bleeding time and a positive Hess test. If the platelets and capillaries are normal, post-traumatic bleeding stops temporarily to be followed by prolonged and gradually increasing bleeding, which may even threaten life.
Laboratory investigations in hemorrhagic disorders
Screening tests: Such as platelet count, prothrombin time (to test the extrinsic coagulation pathway) and partial thromboplastin time (to test the intrinsic coagulation pathway).
A stained blood film should show clumped and single platelets at the rate of 1 for 20-25 erythrocytes. Absence of clumping may suggest thrombasthenia.
The nature of the defect and therefore the most appropriate initial investigations may be suggested by the history and examination, e.g family history, intercurrent disease, alcohol consumption and drugs. Vascular/platelet bleeding is characterized by bruising of the skin and bleeding from mucosal membranes. Bleeding into the skin is manifest as petechiae (small capillary hemorrhages, a few millimeters in diameter) and superficial ecchymoses (larger areas of bleeding).
© 2014 Funom Theophilus Makama