Bleeding Disorders Flashcards
What is a bleeding disorder?
A bleeding disorder refers to an issue with the blood clotting process, leading to abnormally heavy and prolonged bleeding. It can sometimes occur spontaneously.
What are the causes of abnormal bleeding?
Blood vessel/vascular disorders, platelet disorders, or coagulation pathway disorders can cause abnormal bleeding.
What are some examples of inherited blood vessel/vascular disorders?
Two examples of inherited blood vessel/vascular disorders are hereditary haemorrhagic telangiectasia and collagen abnormalities.
What are the characteristics of hereditary haemorrhagic telangiectasia?
- It is an uncommon disorder.
It is inherited in an autosomal dominant manner.
It is characterized by dilated microvascular swellings in various parts of the body, including the skin (hands and fingertips), mucous membranes, and internal organs.
Symptoms may include nose bleeds and gastrointestinal bleeds.
What are the features of collagen abnormalities?
- Collagen abnormalities result in the fragility of the skin, ligaments, blood vessels, and perivascular connective tissue.
Individuals with collagen abnormalities may experience easy bleeding and bruising.
What are some acquired causes of bleeding disorders related to blood vessel/vascular disorders?
Acquired causes include scurvy (vitamin C deficiency), which can lead to bleeding gums, peri-follicular hemorrhages, and bruises. Other causes are steroid Rx (associated with Cushing’s syndrome) and old age.
What are the characteristics of hereditary haemorrhagic telangiectasia?
- It is an uncommon disorder.
It is inherited in an autosomal dominant manner.
It is characterized by dilated microvascular swellings in various parts of the body, including the skin (hands and fingertips), mucous membranes, and internal organs.
Symptoms may include nose bleeds and gastrointestinal bleeds.
What are some platelet disorders related to abnormalities in platelet numbers?
Platelet disorders related to abnormalities in platelet numbers include thrombocytopenia (platelet count < 150 x 109/L). Symptoms of low platelet counts may include epistaxis (nosebleeds), gastrointestinal bleeds, menorrhagia (excessive menstrual bleeding), bruising, and petechiae/purpura.
Are inherited causes of platelet disorders common?
No, inherited causes of platelet disorders are rare. However, when present, they are often associated with other congenital abnormalities, and many individuals show both numerical and functional platelet abnormalities.
Are acquired causes of platelet disorders common?
Yes, acquired causes of platelet disorders are common. These causes can vary and may include various medical conditions or factors.
What is Immune thrombocytopenic purpura (ITP)?
ITP is an autoimmune condition characterized by acute or chronic low platelet counts. In children, it is often acute and follows an infection, resolving on its own. In adults, it can be acute or chronic with various triggers, and the patient’s medical history is important to identify potential causes.
What are some key features of ITP?
ITP can affect both men and women equally. It involves the production of auto-antibodies against platelets, leading to their removal by the spleen. Treatment may be necessary if there is bleeding or if platelet counts drop below 30. Treatment options include steroids, IV immunoglobulins, TPO agonists, monoclonal antibodies, and occasionally splenectomy.
What are some inherited platelet function disorders?
Mutations in membrane glycoproteins or defects in platelet storage organelles or granules can cause inherited platelet function disorders.
What are some acquired platelet function disorders?
Certain drugs, such as aspirin, clopidogrel, and NSAIDs can cause acquired platelet function disorders. Herbal remedies and acquired von Willebrand’s syndrome can also contribute to platelet function abnormalities.
What is haemophilia?
Haemophilia is a bleeding disorder that affects the body’s ability to control blood clotting, which is necessary to stop bleeding. It is often a serious condition.
What are the types of haemophilia based on the affected clotting factor?
Haemophilia A is caused by factor VIII deficiency, while haemophilia B, also known as Christmas disease, is caused by factor IX deficiency.
What are the clinical features of haemophilia?
Clinical features of haemophilia include spontaneous bleeding into joints and muscles, chronic debilitating joint disease, and unexpected post-operative bleeding. Most cases have a family history, although around one-third of cases are due to spontaneous mutations. Haemophilia is carried on the X chromosome.
What are some tests used for coagulation disorders?
Tests for coagulation disorders include APTT (activated partial thromboplastin time), which tests the intrinsic pathway, and PT (prothrombin time), which tests the extrinsic pathway. Other tests include INR (international normalized ratio), TT (thrombin time), fibrinogen level, factor level assay, and bleeding time.
What are the typical blood test results in haemophilia A and B?
In haemophilia A and B, the APTT is prolonged, indicating impairment in factors VII, IX, XI, and XII of the intrinsic pathway. The PT is normal, indicating normal function of factors II, VII, and X in the extrinsic pathway. Haemophilia A shows low factor VIII levels, while haemophilia B shows low factor IX levels. The severity is determined by the percentage of factor levels, with less than 1% being classified as severe, 1-5% as moderate, and greater than 5% as mild.
What are the treatment options for haemophilia?
The treatment of haemophilia involves the use of recombinant DNA to produce products. Infusions of recombinant factor VIII or factor IX are administered to replace the deficient clotting factors. Treatment can be prophylactic, aiming for a level of 50-100% of normal, and administered every 2-3 days. Prophylactic treatment has significantly improved the management of haemophilia patients. On-demand treatment is used only when bleeding occurs or when there is a need to prevent bleeding, such as during surgery.
What is von Willebrand’s factor (vWF)?
Von Willebrand’s factor is a large multimeric glycoprotein synthesized by endothelial cells and megakaryocytes. It acts as a bridging molecule between platelets and collagen at sites of vascular injury, promoting platelet aggregation. Von Willebrand’s disease (vWD) is characterized by a deficiency of vWF and Factor VIII in the plasma. It is the most common inherited clotting abnormality, with several subtypes involving quantitative and qualitative issues with vWF.
What are some common symptoms of von Willebrand’s disease?
Von Willebrand’s disease can lead to mucocutaneous bleeds, nosebleeds, and menorrhagia (excessive menstrual bleeding) due to the deficiency or quality problem of von Willebrand factor.
What are the typical blood test results in von Willebrand’s disease (vWD)?
In vWD, the APTT is either normal or prolonged, the PT is normal, and there is a low vWF level. There may also be vWF function abnormalities and low factor VIII level. Platelet numbers are typically normal or low, and there may be defective platelet function. The bleeding time is often prolonged.
What are the treatment options for von Willebrand’s disease (vWD)?
Treatment of vWD may include the use of desmopressin (DDAVP), which increases the synthesis and release of vWF. Anti-fibrinolytics, such as tranexamic acid, can be used to reduce thrombus breakdown. In more severe cases, plasma products containing vWF and Factor VIII may be administered to replace the deficient components.
