Bleeding Disorders and Haemostasis

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Questions and Answers

What is the platelet count threshold that defines thrombocytopenia?

100 x 10^9/L

250 x 10^9/L

200 x 10^9/L

150 x 10^9/L (correct)

Which of the following is a common trigger for acute Idiopathic Thrombocytopenia Purpura (ITP) in children?

Exposure to anticoagulants

Recent viral infection (correct)

Genetic predisposition

Chronic liver disease

What role does the liver play in coagulation?

It produces coagulation factors. (correct)

It stores platelets for future use.

It destroys old platelets.

It actively inhibits blood clotting.

What condition is characterized by the immune system mistakenly attacking its own platelets?

Idiopathic Thrombocytopenia Purpura (ITP) Signup and view all the answers

Which vitamin deficiency can contribute to a bleeding disorder?

Vitamin K Signup and view all the answers

What kind of disorders may result in altered platelet function?

Connective tissue disorders Signup and view all the answers

What is a common consequence of renal disease in relation to platelets?

Decreased platelet lifespan Signup and view all the answers

Which of the following is NOT a cause of thrombocytopenia?

Increased platelet production Signup and view all the answers

Which of the following best describes chronic ITP?

Can occur at any age Signup and view all the answers

What does Hereditary haemorrhagic telangiectasia (HHT) primarily affect?

Vascular structure Signup and view all the answers

What is the primary function of haemostasis in the body?

To prevent significant blood loss after vascular injury Signup and view all the answers

Which of the following sequences accurately describes the events in haemostasis?

Vasoconstriction, platelet activation, coagulation cascade activation Signup and view all the answers

Which type of bleeding disorder involves the connective tissue defects?

Disorders of blood vessels Signup and view all the answers

What is a potential impact of medical conditions on oral health?

Altered bleeding risk during dental procedures Signup and view all the answers

Which of the following best describes the role of the dental team regarding wider healthcare?

To act as a referral point to other healthcare professionals Signup and view all the answers

What should dental professionals consider regarding patient treatment plans?

Patient’s uniqueness in needs compared to the planned approach Signup and view all the answers

How are bleeding disorders primarily classified?

By the mechanism or level of blood component involvement Signup and view all the answers

Which component is NOT part of the coagulation cascade?

Vasoconstrictor substances Signup and view all the answers

What is the first response of the vascular system when an injury occurs?

Vasoconstriction Signup and view all the answers

Which factor is essential for the formation of a fibrin plug during clotting?

Calcium ions Signup and view all the answers

What is the duration of maximal effect for Direct Oral Anticoagulants?

36 hours Signup and view all the answers

Which Direct Oral Anticoagulant does not currently have a reversal agent?

Edoxaban Signup and view all the answers

What is a characteristic feature of Dabigatran as an anticoagulant?

Reversible thrombin inhibitor Signup and view all the answers

What is the main route of administration for Heparin?

Intravenously in hospitals Signup and view all the answers

How long is the half-life of Heparin?

1-2 hours Signup and view all the answers

What is one benefit of using Direct Oral Anticoagulants over Warfarin?

Fewer food and drug interactions Signup and view all the answers

In what context is 'Minihep' primarily used?

To reduce risk of deep vein thrombosis in pregnant women Signup and view all the answers

What is the onset time for Direct Oral Anticoagulants compared to Warfarin?

1-4 hours faster Signup and view all the answers

What do Apixaban, Dabigatran, and Rivaroxaban all share?

They prevent thrombin generation Signup and view all the answers

Which of the following is true about bleeding risk and dental treatment?

Advice is necessary for any patient taking anticoagulants before invasive dental treatment Signup and view all the answers

Which of the following is a common complication of chronic liver disease that can lead to post-operative bleeding?

Decreased production of clotting factors Signup and view all the answers

What is the most common type of inherited coagulation disorder?

Haemophilia A Signup and view all the answers

Which is a treatment option for Von Willebrand disease?

Tranexamic acid Signup and view all the answers

Which of the following accurately describes Haemophilia B?

Males are primarily affected while females are carriers Signup and view all the answers

Which of the following is NOT a consequence of chronic renal failure on hemostasis?

Elevated platelet factor 3 Signup and view all the answers

What is the primary mechanism of action of Warfarin?

Blocks vitamin K usage in producing clotting factors Signup and view all the answers

What is the target INR level for patients on Warfarin for atrial fibrillation?

2.5-3.5 ± 0.5 Signup and view all the answers

Which of the following factors is associated with post-operative bleeding in alcohol-dependent patients?

Folate deficiency leading to thrombocytopenia Signup and view all the answers

Which class of drugs is indicated for ischaemic heart disease?

Antiplatelet drugs Signup and view all the answers

Which inherited coagulation disorder is characterized by a deficiency of von Willebrand factor?

Von Willebrand disease Signup and view all the answers

Study Notes

Bleeding Disorders (Part 1)

Bleeding disorders are a significant concern in oral health.
This session is aimed at educating dental hygienists/therapists about bleeding disorders.
GDC learning outcomes include explaining general and systemic diseases, relevant physiology, recognizing oral cavity abnormalities and patient concerns, and adjusting treatment plans according to patient needs.
Learning outcomes also include understanding the impact of medical conditions and psychological conditions.

Haemostasis

Haemostasis is the body's physiological response to vascular injury, preventing significant blood loss.
Three main events in haemostasis are:
- Vascular system: the injured vessel constricts.
- Platelet system: platelets aggregate to form a plug.
- Coagulation cascade: the cascade produces a fibrin plug.

Aggregation of Platelets

Platelet activation involves three stages:
- Adhesion: platelets stick to the damaged blood vessel wall.
- Secretion: platelets release substances to promote clotting.
- Aggregation: platelets clump together to form a plug.

The Coagulation Cascade

The coagulation cascade is a complex series of reactions involving various clotting factors.
The cascade has two main pathways:
- Intrinsic pathway: initiated by contact with a damaged surface.
- Extrinsic pathway: initiated by tissue damage.

Classification of Bleeding Disorders

Bleeding disorders can be categorized into disorders of:
- Blood vessels
- Platelets
- Coagulation

Disorders of Blood Vessels

Inherited disorders include connective tissue disorders (e.g., Ehlers-Danlos Syndrome) and hereditary hemorrhagic telangiectasia (HHT).
Acquired disorders include severe infections (e.g., meningococcal, typhoid), medications (e.g., sulphonamides), and other conditions (e.g., vitamin C deficiency, senile purpura).

Disorders of Platelets

Disorders of platelets include:
- Thrombocytopenia (low platelet count)
  - Idiopathic Thrombocytopenia Purpura (ITP)
  - Liver disease
  - Renal disease
  - Chemotherapy
  - Radiotherapy
  - Connective tissue disorders
  - Rare diseases (Bernard-Soulier, Jacobsen, Lowe)
  - Antiplatelet drugs
Thrombocytopenia can result from decreased/failed platelet production, destruction of circulating platelets or from platelet function disorders.
Idiopathic Thrombocytopenic Purpura (ITP) is an autoimmune disorder resulting from the immune system attacking platelets. It has acute and chronic forms.

Disorders of Platelets cont.

Liver disease affects blood clotting. The liver produces clotting factors, and liver disease can lead to mal-absorption of fat-soluble vitamins such as vitamin K.
Patients with chronic liver disease and post-operative patients dependent on alcohol may have increased postoperative bleeding due to decreased clotting factor production, bone marrow suppression, or folate deficiency causing thrombocytopenia.
Malnutrition from heavy drinking can decrease the synthesis of vitamin K-dependent clotting factors.
Renal disease impairs haemostasis due to impaired platelet production, a decrease in platelet factor 3 and vasodilation. Renal failure patients taking heparin may also have impaired haemostasis.

Disorders of Coagulation

Inherited disorders include Haemophilia A, Haemophilia B (Christmas Disease), and Von Willebrand Disease.
Acquired disorders include liver disease, hematological malignancies, and anticoagulant drugs.

Haemophilia A

Most common type of haemophilia.
Deficiency in clotting factor VIII.
X-linked recessive condition affecting mostly males. Females can be carriers.
Presents with bleeding (nosebleeds, bleeding gums, easy bruising, joint pain and stiffness).

Haemophilia B (Christmas Disease)

Less common than Haemophilia A.
Deficiency in clotting factor IX.
X-linked recessive condition affecting mostly males.
Presents with similar bleeding symptoms as Haemophilia A.

Von Willebrand Disease

Most common hereditary coagulation abnormality.
Deficiency or dysfunction of von Willebrand factor (vWF).
VWF is crucial for factor VIII and platelet adhesion and aggregation.
Presentation similar to platelet dysfunction.
Treated with medications like desmopressin, tranexamic acid, and factor VIII replacement.

Antiplatelet and Anticoagulant Drugs

Antiplatelet drugs are used to prevent blood clots and include:
- Aspirin
- Clopidogrel
- Dipyridamole
- Ticagrelor
- Prasugrel
Indications include ischaemic heart disease, previous myocardial infraction, atrial fibrillation, coronary stent placement, previous stroke and renal transplant.
Anticoagulant drugs are used to prevent blood clots.
- Warfarin
- Direct oral anticoagulants (DOACs) : Rivaroxaban, Apixaban, Edoxaban, Dabigatran
- Heparin
Indications for anticoagulants include stroke, transient ischaemic attack, deep vein thrombosis, pulmonary embolism, atrial fibrillation, and heart valve surgery.

Warfarin

Vitamin K antagonist that blocks enzymes requiring vitamin K to produce clotting factors.
Monitored using the international normalized ratio (INR).
Target INR can vary depending on the condition.
Long half-life, effect begins in 8-12 hours, with maximal effect at 36 hours and lasts 72 hours.
Many interactions with other medications.

Direct Oral Anticoagulant Drugs (DOACs)

Work by inhibiting factor Xa or thrombin.
Rapid onset of action (1-4 hours).
Fewer food and drug interactions than Warfarin.
Usually no need for routine INR monitoring.
Some have reversal agents.

Heparin

Short half-life (1-2 hours).
Primarily used intravenously in hospitals.
Used in dialysis, and in pregnant women or after surgery to prevent deep vein thrombosis or thrombosis after myocardial infarction.

Summary

The summary highlights the importance of knowledge of haemostasis, classification of bleeding disorders. and familiarity with medical conditions and drug therapies that affect the bleeding risks for patients.

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Description

This quiz focuses on understanding bleeding disorders and the body's haemostasis process, essential knowledge for dental hygienists and therapists. It covers key physiological responses to vascular injury, platelet aggregation, and the overall impact of systemic diseases on oral health. Enhance your expertise in managing patients with bleeding disorders through this informative session.

Bleeding Disorders and Haemostasis - Part 1

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