hemorrhage and hemorrhagic disorders

hemorrhage

hemorrhagic disorders

excessive bleeding can result from deficiency of one of the many different blood clotting factors.

the hemorrhagic disorders are:

1- hemorrhagic disorders due to abnormalities of blood platelets:

thrombocytopenia ( thrombocytopenic purpura)

this is a disease characterized by a very low level of platelets i.e. below 50.000\cubicm

there is tendency of spontaneous bleeding from many small capillaries ,usually beneath the skin from mucous membranes and internal organs .

the skin shows many small , purplish spots giving the disease the name thrombocytopenic purpura .

types:

a-idiopathic thrombocytopenia   the cause is unknown

b-secondary thrombocytopenia    occurs in association with aplasia of the bone marrow e.g.  exposure to X rays ,radioactive substances ,neoplastic deposits ,very severe fevers and drug sensitivity.

thrombasthenia

it is a state in which the platelets are normal in quantity but defective in function which may result in a bleeding tendency

it may be primary or secondary e.g. in severe uremia and exposure to certain drugs as aspirin

2-hemorrhagic disorders due to defect in the clotting mechanisms.

hemophilia:

- it is inherited   X - linked disease transmitted by females (mothers) to males (infants) but females themselves show no symptoms.

the condition is characterized by marked increase in the coagulation time i.e. a slight injury causes severe hemorrhage which may continue for several hours.

types:

a- hemophilia A   85% : classical  hemophilia

b- hemophilia B 10%:  Christmas disease

c-hemophilia C   5%

vit k deficiency: 

most of the blood coagulation factors require vit k synthesis by the liver therefore ,in absence of vit k the formation of these factors is depressed and the patient develops a severe tendency to bleed.

causes of vit k deficiency:

1- sterility of the intestine (no bacteria) in new born infants and prolonged use of antibiotics.

2- failure of absorption ofVIT K in obstructive jaundice & fatty diarrhea.

3- liver diseases.

4- dicumarol.

 

 3- intravascular thrombosis.

it is the formation of blood clot inside the blood vessels.

common causes:

a-slowing of the blood :

 e.g. after delivery and operation the slow blood flow allows the activated clotting factors to accumulate instead of being washed away .

b- atherosclerosis:

e.g. coronary and cerebral atherosclerosis leads to injury of endothelium and platelets aggregation.

 complications:

1- obstruction of arterial supply which leads to ischaemia and necrosis of the affected organ.

2-obstruction of venous supply which leads to edema.

3- embolic formation i.e dislodgment of small pieces of the blood clot which are carried by the blood stream to affect other organs e.g. pulmonary emboli.

 prevention:

a- avoidance of prolonged recumbence.

b- use of anticoagulant in susceptible patients. 

REFERENCES:

1. ^ ^{a b c d e} Wiskott-Aldrich Syndrome The International Patient Organisation for Primary Immunodeficiencies (IPOPI).
2. ^ ^{a b c d e f g h i} Disorders of thrombosis and hemostasis: clinical and laboratory practice. Page Rodger L. Bick. Edition 3, illustrated. ISBN 0-397-51690-8, ISBN 978-0-397-51690-2. 446 pages
3. ^ ^{a b c} Vitamin K Deficiency eMedicine. Author: Pankaj Patel, MD. Coauthor(s): Mageda Mikhail, MD, Assistant Professor. Updated: Dec 18, 2008
4. ^ ^{a b c d} Hemophilia Complications By Mayo Clinic staff. May 16, 2009
5. ^ ^{a b c d} Von Willebrand disease --> Complications By Mayo Clinic staff. Feb. 7, 2009