Haematology

Question 1

What type of drug is Warfarin ?

Answer 1

Anticoagulant.

Question 2

What is Warfarin used to treat ?

Answer 2

DVT, pulmonary embolism, cerebrovascular incident, MI prophylaxis.

Question 3

How does Warfarin work ?

Answer 3

Inhibits vitamin K-dependent modification of prothrombin and other clotting factors - clotting factors II, VII, IX, and X.

Question 4

What should a patient’s INR be to be able to successfully complete dental care safely in primary care setting ?

Answer 4

Between 2-4.

Question 5

Patient has unstable INR - when should bloods be checked prior to treatment ?

Answer 5

Within 24 hours.

Question 6

Patient has stable INR - when should bloods be checked prior to treatment ?

Answer 6

Within 72 hours.

Question 7

If patient has INR > 4 and their treatment is urgent, where should their care be carried out ?

Answer 7

Secondary care setting.

Question 8

What operative considerations should be given to patient taking warfarin ?

Answer 8

Haemostatic measures - suturing, packing, injection of LA etc.

Question 9

A patient who is taking DOAC requires minimally invasive treatment - what 3 considerations should you take ?

Answer 9

Plan treatment early in the day.
Limit the initial treatment area.
Strongly consider suturing and packing.

Question 10

A patient who is taking apixaban DOAC requires invasive treatment - what should you advise the patient to do prior to procedure ?

Answer 10

Miss morning dose.

Question 11

A patient who is taking rivaroxaban or edoxaban DOAC requires invasive treatment - what should you. advise the patient to do prior to the procedure ?

Answer 11

Delay morning dose.

Question 12

How does Apixban and Rivaroxaban work ?

Answer 12

Inhibit Factor Xa in coagulation cascade.

Question 13

What is the benefit of DOACs vs. Warfarin ?

Answer 13

DOACs have more predictable outcome of anticoagulation and do not require same degree of monitoring so safer and more effective.

Question 14

Why do patients with chronic renal failure have increased bleeding tendency ?

Answer 14

Associated platelet dysfunction - impaired platelet adhesiveness and aggregation ability.

Question 15

Why do patients with liver disease have increased bleeding tendency ?

Answer 15

Reduced production of coagulation factors.
Reduced platelet number and function due to splenomegaly.
Thrombocytopenia - as thrombopoietin produced in liver is reduced when liver cell mass is severely damaged.

Question 16

Why do patients with Ehlers Danlos Syndrome have increased bleeding tendency ?

Answer 16

Vascular fragility due to connective tissue disease and platelet function abnormalities.

Question 17

What are haemostatic packing materials which can be used to aid achieving haemostasis ?

Answer 17

Oxidised cellulose framework i.e. Surgicel.
Collagen sponge.

Question 18

What type of drug is Simvastatin ?

Answer 18

HMG-CoA reductase inhibitor (statins) - slow the production of cholesterol, lipid lowering drug.

Question 19

What test is used to assess patient’s diabetic control ?

Answer 19

HbA1c test -
<42mmol/mol is normal.
42-47mmol/mol is pre-diabetic.
>47mmol/mol is diabetes.

Question 20

What BP indicates hypertension ?

Answer 20

Exceeding 140/90mmHg.

Question 21

What is the dental implication of simvastatin ?

Answer 21

Interacts with fluconazole - either stop medication or prescribe nystatin.