Bleeding

Question 1

Describe a commonly used bleeding assessment tool

Answer 1

ISTH Bleeding Assessment Tool

Question 2

Describe how the ISTH BAT works

Answer 2

• A series of 14 sites of bleeding questioned and scored depending on severity of symptoms from patient
• Woman abnormal over 6, men over 4 and children over 2
• Oral cavity bleeding and after extraction are two items on ISTH BAT

Question 3

Name 2 blood panel investigations

Answer 3

1. Full blood count

2. Coagulation screen

Question 4

Describe the physiologic cascade leading to clotting

Answer 4

• Injury leads to release of tissue factor
• Factor XI cascade leads to production of factor X
• Tissue factor converts Factor X into Factor Xa
• Factor Xa converts prothrombin to thrombin
• Thrombin converts fibrinogen into fibrin which causes clots

Question 5

Describe how clotting time is affected by extrinsic pathway deficiency

Answer 5

Prolongs PT only

Question 6

Describe how clotting time is affected by common pathway deficiency

Answer 6

Prolongs both PT and APTT

Question 7

What does APTT stand for?

Answer 7

Activated platelet thromboplastin time

Question 8

Describe how extrinsic pathway deficiencies arise

Answer 8

Factor VII deficiencies
     Oral warfarin therapy
     Sepsis
     Congenital deficiency
     Early vitamin K deficiency

Question 9

Describe how common pathway deficiencies arise

Answer 9

• Vitamin K deficiency (Factors II, VII, IX, X)
• Oral warfarin and dabigatran therapies
• DIC

Question 10

What does DIC stand for?

Answer 10

Disseminated Intravascular Coagulopathy

Question 11

Name 3 reasons DIC may be used

Answer 11

1. Septicaemia
2. Meningitis
3. Malignancy

Question 12

Describe how intrinsic pathway deficiencies arise

Answer 12

• DIC
• Liver disease
• Heparin contamination / therapy monitoring
• Warfarin / anticoagulant therapy
• Factor VIII, IX, XI and XII deficiency

Question 13

Name 3 common causes for bleeding disorders

Answer 13

1. Abnormal vascular endothelium
2. Deficiency of Clotting Factors
3. Platelet abnormalities

Question 14

Name 3 examples of vascular endothelium disorders

Answer 14

1. Patterson Kelly Brown Syndrome
2. Osler Weber Renu Syndrome
3. Ehlers Danlos Syndrome

Question 15

What category of diseases do Patterson Kelly Brown and Osler Weber Renu syndromes fall into?

Answer 15

Hereditary Haemorrhagic Telangiectasia

Question 16

Name 3 common hereditary coagulation disorders

Answer 16

1. Haemophilia A
2. Haemophilia B
3. Von Willebrand’s Disease

Question 17

What is the difference between haemophilia A and haemophilia B?

Answer 17

Haemophilia A is a deficiency of factor VIII and haemophilia B is a deficiency of factor IX

Question 18

Describe haemophilia with regards to its hereditary features

Answer 18

• X linked condition
• Only males affected
• 1 in 5000 people affected
• 1 in 3 cases are spontaneous mutations

Question 19

Describe the 4 degrees of severity in haemophilia

Answer 19

Normal - Not infected
Mild - Usually need fall or dental extraction to bring on bleeding
Moderate - Can be spontaneous bleeding but usually must be provoked
Severe - Need injected with IV clotting factor

Question 20

Describe common bleeds in a patient suffering from haemophilia

Answer 20

• Major haemorrhage into joints (knees, elbows and ankles) causing pain
• Chronic haemorrhage causes degenerative joints changes
• Joints are tender, warm and distended
• Intracranial, intramuscular and traumatic haemorrhage also common

Question 21

Describe the review process for dentists of patients suffering from haemophilia

Answer 21

• All patients with severe or moderate deficiency reviewed in hospital every 6 months
• All patients with mild deficiency reviewed in GDP 6 monthly and hospital setting every 2 years

Question 22

Describe the epidemiology of Von Willebrand’s Disease

Answer 22

• Most common inherited bleeding disorder
• Affects male and females equally
• Affects 1:1000 people

Question 23

Describe the disease process of Von Willebrand’s Disease

Answer 23

• Von Willebrand’s factor is glycoprotein secreted by endothelium and megakaryocytes
• VWF promotes platelet adhesion to damaged endothelium and other platelets
• VWF stabilises and transports factor VIII
• Deficiency of VWF causes abnormal platelet function and low factor VIII activity

Question 24

Name 3 common bleeding patterns in VWD

Answer 24

1. Epistaxis
2. Menorrhagia
3. Bleeding after surgical challenge

Question 25

What is epistaxis?

Answer 25

Nose bleeds

Question 26

What is menorrhagia?

Answer 26

Heavy menstrual periods

Question 27

Describe 3 types of VWD

Answer 27

Type 1 (quantitative) = Protein works but low amount
Type 2 (qualitative) = Protein is present but doesn't work
Type 3 (absence) = Abnormal gene inherited so no WVF present

Question 28

Aside from extractions, what are the dental implications for VWD and haemophilia?

Answer 28

Local anaesthetic administration

Question 29

Describe 3 dental times when cover is required for patients with bleeding disorders

Answer 29

1. Inferior dental block
2. Lingual infiltration
3. All extractions

Question 30

Name 4 rare congenital platelet disorders

Answer 30

1. Bernard Soullier syndrome
2. Glanzmanns thrombasthenia
3. Storage pool disorders
4. Hermansky Pudlak syndrome

Question 31

Name 4 commonly acquired platelet disorders

Answer 31

1. Antiplatelet therapies
2. NSAID therapy
3. SSRI antidepressant therapies
4. Herbal medications