Acquired bleeding and anticoagulants Flashcards
1
Q
What is thrombophilia?
A
- Increased risk of clots developing
- Often an acquired condition superimposed on a genetic condition
- Usually possible to find a cause for the clot
2
Q
What are possible inherited causes of thrombophilia? (4 points)
A
- Protein C deficiency
- Protein S deficiency
- Factor V Leiden
- Antithrombin III deficiency
3
Q
What are acquired causes of thrombophilia? (7 points)
A
- Antiphospholipid syndrome
- Oral contraceptives
- Surgery
- Trauma
- Cancer
- Pregnancy
- Immobilisation
4
Q
What is thrombocytopenia?
A
- Reduced platelet numbers
5
Q
What is a qualitative disorder?
A
- Normal platelet number but abnormal function
6
Q
What is thrombocythemia?
A
Increased platelet numbers
7
Q
What are the possible causes of thrombocytopenia? (3 points)
A
- Idiopathic
- Drug related (alcohol, penicillin’s, Heparin)
- Secondary to lymphoproliferative disorder
8
Q
Dental treatment can proceed safely providing the platelet count is what?
A
> 50*10^9
9
Q
Are inherited qualitative disorders common or rare?
A
Rare
10
Q
What are examples of acquired qualitative disorders? (4 points)
A
- Cirrhosis
- Drugs
- Alcohol
- Cardiopulmonary bypass (tend to have platelets that don’t work well)
11
Q
Is thrombocythemia common or uncommon?
A
Uncommon disease
12
Q
What medication are patients with thrombocythemia usually on to prevent clot formation?
A
Usually on aspirin
13
Q
What are common causes of liver disease? (3 points)
A
- Alcohol
- Hepatitis
- Drug indiced
14
Q
What is the value of a normal INR?
A
- 1
15
Q
What is the haematological change in haemoglobin in liver disease?
A
Little change
16
Q
What is the haematological change in platelets in liver disease?
A
Decrease
17
Q
What is the haematological change in PT in liver disease?
A
Increase
18
Q
What is the haematological change in APPT in liver disease?
A
Increase
19
Q
What is the haematological change in TT in liver disease?
A
Increase
20
Q
What does PT mean?
A
Prothrombin time
21
Q
What does APTT stand for?
A
- Activated Partial Thromboplastin Time
22
Q
What effect does mild stage liver disease have on dental surgery?
A
- Blood results often normal so normal precautions apply
23
Q
What effect does moderate stage liver disease have on dental surgery? (3 points)
A
- Often only one parameter abnormal and platelet count >100
- No problem with treatment
- Local measures following extraction
24
Q
What effect does severe stage liver disease have on dental surgery? (3 points)
A
- All blood results abnormal
- Problems with haemostasis
- Extractions MUST be carried out in conjunction with haematologist
25
What are 3 examples of anti-thrombotic medication?
- Oral anticoagulation (swallow - not injection)
- Heparins (injection)
- Antiplatelet medication (by mouth)
26
What are possible indications for anticoagulation? (5 points)
- Atrial fibrillation
- Deep vein thrombosis
- Heart valve disease
- Mechanical heart valves
- Thrombophilia
27
What are 3 subtypes of oral anticoagulants?
- Coumarins
- Direct Factor Xa inhibitors
- Direct Thrombin Inhibitors
28
What is an example of a coumarin (type of oral anticoagulant)?
- Warfarin
29
What are 2 examples of direct factor Xa inhibitors (type of oral anticoagulant)?
- Rivaroxaban
| - Apixaban
30
What is an example of a direct thrombin inhibitor (type of oral anticoagulant)?
- Dabigatran
31
Give 3 examples of new oral anticoagulants?
- Rivaroxiban
- Apixiban
- Dabigatran
32
Why are new oral anticoagulants increasing used over warfarin?
- They are 'safer' and 'cheaper' alternative
| - No monitoring needed routinely
33
What is the daily dose of warfarin?
1-15mg
34
What is the response of warfarin measured by?
- Measured using the INR
35
When should the INR be checked for someone on warfarin?
Every 4-8 weeks
36
What are examples of potentiating drugs when combined with warfarin? (4 points)
- Aminodarone
- Antibiotics
- Alcohol (with liver disease)
- NSAID's
37
What are examples of inhibiting drugs when combined with warfarin? (4 points)
- Carbamazepine, barbiturates
- Cholestyramine
- Griseofulvin
- Alcohol (without liver disease)
38
What are examples of medicines you should use with caution when a patient is on Warfarin? (3 points)
- Aspirin (as an analgesic)
- Most antibiotics (amoxycillin least likely to cause problems)
- Azole antifungal drugs (fluconazole, itraconazole)
39
What should you assume with warfarin?
- Assume all drugs interact with warfarin
- Always seek advice from GP if you are prescribing
- INR check needed in 24-48hrs
40
What is the INR (international normalised ratio)?
- INR= Patient PT/ mean normal PT
41
What is the target INR for patients with mechanical heart valves?
3.0-4.0
42
What is the target INR for patients with recurrent VTE while adequately anticoagulated?
3.0-4.0
43
What is the target INR for patients with atrial fibrillation?
2.0-3.0
44
What is the INR range that you roughly want a patient to be in?
2.0-4.0
45
What is a common risk of being on warfarin?
- HAEMORRHAGE RISK
- 1% per annum risk of serious bleed (needing hospitalization/transfusion)
- 25% of these are fatal
46
What are common risks of adjusting a patients INR? (4 points)
- Fatal thromboembolic events
- Non-fatal thromboembolic events
- Rebound hypercoagulable st ate
- Restarting warfarin makes coagulation more likely
47
What are examples of dental treatments where the INR must be checked? (4 points)
- Extractions
- Minor oral surgery
- Periodontal surgery
- Biopsies
48
What are examples of dental treatments where the INR is not checked? (4 points)
- PRosthodontics
- Conservation
- Endodontics
- Hygiene phase therapy
49
What are the SDCEP guidelines in relation to giving injections on a patient on warfarin? (3 points)
- Use a LA containing a vaso-constrictor
- Where possible use an infiltration, intraligamentary or mental nerve injection
- If there is no alternative an inferior alveolar nerve block is used the injection should be administered slowly using an aspirating technique
50
When should you treat a patient on warfarin?
- In the morning, early in the week
51
When must the INR of a patient on warfarin be checked prior to dental treatment?
- Must be checked in the 48 hours prior to treatment but should be as near as possible to the time of treatment
52
What must the INR of a patient on warfarin be so dental treatment can proceed?
must be <4.0
53
When extracting teeth on a patient on warfarin. How many teeth should you remove at a time?
- No more then three roots
54
What are local measures to aid haemostasis of a patient on warfarin after having dental treatment? (4 points)
- LA infiltration
- Oxidised cellulose
- Sutures
- Pressure
55
What are good post operative instructions to give to a patient on warfarin after being given dental treatment?
- Must include emergency contact details
56
How are unfractionated heparins administered?
- Given by IV infusion in hospital
| - Very short half life so very controllable
57
How are low molecular weight heparins administered?
- Given by subcutaneous injection by the patient at home
| - Dose weight related - no monitoring
58
What are examples of drugs available as antiplatelet medication? (4 points)
- Low dose aspirin (75mg daily)
- Clopidogrel
- Dipyridamole
- Ticlopidine
59
If a patient is on an anticoagulant and antiplatelet therapy, what should you do?
- Discuss with a hospital therapist
| - Each individual case is slightly different
