What
is bleeding tendency?
In any bleeding episodes, there will be a breach in the continuity of the blood
vessel walls involved. Therefore, in the physiologic or normal situations, the
damaged segment of the vessel wall will initiate the repair by enlisting the
help of both the platelets and the clotting proteins. Platelets are small blood
cells that can be activated and aggregated to form a platelet plug to seal the
vessel wall breach. The platelet plug will also provide a conducive surface
upon which the clotting proteins can react. The clotting proteins once activated
will ultimately culminate in the laying down of a fiber network over the initial
platelet plug. This fiber network serves to strengthen the platelet plug in
sealing the vessel breach. However, once the inciting agents have been eliminated
and the underlying vessel damages repaired, the fiber network and platelet plug
will be removed. Therefore in anyone who has an abnormal or pathological bleeding
tendency, it may result from abnormalities in the a) vessel walls, b) platelets,
and/or c) clotting proteins.
There are many causes to vessel defects eg. hereditary (ie Ehlers Danlos syndrome), nutrient deficiency (ie Vit C deficiency), drug induced (ie steroid induced), aging (senile purpura), certain infections (ie streptococcal, meningococcal infections), malignancies (ie lymphoma, leukemia), etc.
The platelet disorders are often subdivided into either quantitative (ie thrombocytopenia) or qualitative problems ( ie platelet dysfunction). The former can be a result of decreased platelet production in the bone marrow or an increased destruction/loss of platelets in the peripheral blood stream. The causes can likewise be a primary platelet disorder (eg hereditary, nutrient deficiency, infections, drug induced, etc) or secondary to other disease states affecting the marrow or peripheral blood (eg other malignancies, autoimmune disorder, etc).
Clotting defects can either be due to an abnormal production or an accelerated removal of the fiber clots. The common cause of defective production is the hereditary deficiency of clotting factors (eg hemophilia, von Willebrand disease, etc). The problem with an accelerated removal of fiber clots is by far very rare, but nevertheless, could still result from a deficiency of the regulatory proteins in clot removal (eg plasminogen activator inhibitor deficiency).
Diagnostic
tests
Clinically, vessel wall defects and platelet disorders more often will produce
superficial bleeding eg skin petechiae and mucosal bleeding, in contrast to
clotting disorders which tend to cause deep bleeding eg intramuscular bleed,
joint bleed etc. Furthermore, certain screening blood tests as well as other
confirmatory laboratory tests can differentiate the various disorders.
Treatment
of bleeding tendency
As in other medical disorders, the management is directed at eliminating the
inciting factors and restoring the normal clotting function. These are translated
into clinical practice as administration of pharmaceutical agents, surgical
procedures, and blood/blood products transfusion.