Abnormal Bleeding

Question 1

Name some times you’ll experience patients bleeding in dentistry

Answer 1

1. Tooth extraction
2. Surgery
3. Biopsies
4. Trauma
5. Periodontal therapy
6. Pulpal exposure

Question 2

Give some effects of blood loss

Answer 2

1. Patient distress
2. Blood in the tissues (bruising, infection)
3. Blood in the stomach
4. Blood in the airways
5. Reduced oxygen flow
6. Reduced protein and platelets
7. Hypovolaemia

Question 3

What is Hypovolaemia

Answer 3

Reduced blood flow

Question 4

wHAT CAN Hypovolaemia lead to

Answer 4

Shock

Question 5

How do we manage bleeding

Answer 5

1. Be prepared
2. Inform the patent before hand that they may bleed
3. Check bleeding and clotting history
4. Be as conservative as possible and dont plan multiple extractions in one visit
5. Local measures
6. Careful post op care and follow up

Question 6

What local measures do we take to manage bleeding

Answer 6

1. Pressure
2. Suture
3. Surgicel
4. Patients

Question 7

What is virchow’s triad

Answer 7

Describes 3 factors that important in valour formation:

1) blood flow
2) activation of blood coagulation
3) vein damage

Question 8

What is Haemostasis

Answer 8

Prevention of blood loss

Question 9

How is Haemostasis achieved

Answer 9

1. Vascular spasm
2. Platelet plug
3. Blood coagulation
4. Growth of fibrous tissue in the hole in the vessel permanently

Question 10

What is vascular spasm

Answer 10

When smooth muscle in the blood vessel walls contacts and reduces blood loss

Question 11

What is the aim of the vascular spasm

Answer 11

Prevents excessive blood floss in the body

Question 12

How is a platelet plug formed

Answer 12

1. Platelet adhere to exposed tissue collagen
2. Platelets release thromboxane A2 which increases stickiness
3. Platelet aggregation

Question 13

What does aspirin do

Answer 13

It irreversibly binds to platelets and inactivates platelet COX

Question 14

What is platelet COX

Answer 14

cyclooxygenase

Question 15

What is the significance of cyclooxygenase

Answer 15

It is required for thromboxane A2 mediated aggregation

Question 16

How does clopidogrel work

Answer 16

It binds to the P2Y12 receptor irreversibly and prevents Adenosine Di Phosphate (ADP) mediated aggregation

Question 17

How long does it take for platelets renewed

Answer 17

about 10 days

Question 18

How does Ibuprofen work

Answer 18

Ibuprofen binds to platelets reversibly

Question 19

How does platelet plug formation activate the coagulation cascade

Answer 19

1. Tissue damage
2. Exposure of sub endothelial collagen
3. Platelet adhesion
4. Enhances platelet adhesion and aggregation
5. Enhanced activation of factor X and prothrombin

Question 20

Which patients are likely to be taking clopidogrel or aspirin?

Answer 20

Patients with:

1. Vascular disease
2. Ischaemic heart disease
3. thromboembolic disease
4. Stroke
5. peripheral vascular disease
6. In whom thrombi are more likely to form

Question 21

What is a thrombi

Answer 21

Platelet aggregations

Question 22

What affect does aspirin have on tooth socket bleeding time

Answer 22

Patients who take aspirin have a longer tooth socket bleeding time

Question 23

Should we tell patients taking aspirin to stop taking it before their extraction? Why?

Answer 23

NO:
Takes weeks for effect to be reversed
Risk of stopping is greater than risk of continuing

Question 24

List some tests we can take to test bleeding function

Answer 24

1. INR (International normalised ratio)
2. Platelet count
3. APTT (Activated Partial Thromboplastin Time)

Question 25

Name the 2 pathways of the clotting cascading

Answer 25

1. Intrinsic pathway | 2. Extrinsic pathway

Question 26

What is the intrinsic pathway initiated by

Answer 26

1. Exposed collage | 2. Platelet activation

Question 27

What is the extrinsic pathway initiated by

Answer 27

Tissue damage

Question 28

What is the overall effect of the intrinsic and extrinsic pathway

Answer 28

They both meet together at the end and activate Prothrombin | This then activated thrombin which turns fibrinogen into fibrin

Question 29

What is the normal Platelet count

Answer 29

normal 200-400 *10^9/L

Question 30

A platelet count lower than what indicates a bleeding problem

Answer 30

lower than 100 *10^9/L

Question 31

Which bleeding test is the most commonly used

Answer 31

INR (especially in patents taking warfarin)

Question 32

Which patients are likely to be taking warfarin? | 1

Answer 32

Patients with: 1. Atrial fibrillation 2. Heart valve abnormalities or replacement 3. Thromboembolic disease 4. ischaemic heart disease

Question 33

How does warfarin work

Answer 33

It prevents the action of vitamin K which prevents carboxylation of clotting factor precursors

Question 34

Why is vitamin K important in blood clotting

Answer 34

It is require by the liver to produce factors II, VII, IX and X

Question 35

What is the half life for clotting factors

Answer 35

60 hours

Question 36

When is the full impact of warfarin seen in a patient

Answer 36

About 7 days

Question 37

What are the disadvantage of warfarin

Answer 37

1. Multiple drug interactions 2. Difficult to get stable anti-coagulation 3. Some food interactions 4. Needs to be monitored

Question 38

Which drugs can warfarin interact with

Answer 38

``` Metronidazole Carbamazepine Fluconazole Miconazole St Johns Wort ```

Question 39

What foods can warfarin interact with

Answer 39

Cranberry juice

Question 40

An INR below what is safe to do an extraction on

Answer 40

less than 4

Question 41

When should we check INR records of a patient

Answer 41

If stable, check INR 72hrs before extraction | If not check within 24hrs

Question 42

Give some advantages of new anticoagulants

Answer 42

1. Single point of action 2. Predictable effect 3. No need for INR monitoring 4. No interaction with food

Question 43

Give some disavantages of new anticoagulants

Answer 43

No antidote | Half life up to 17hrs

Question 44

How can we ask patients if they have any bleeding problems

Answer 44

1. Do you have any problems with bleeding or bruising? 2. Are you taking any medicines to thin the blood? 3. Do you have any liver problems?