Unit 14 - Haematological Disorders (Anti-Thrombotic Agents)

What is haemostasis?

Mechanism that leads to bleeding stopping from a blood vessel. Involves 3 steps:

1) Vascular spasm

2) Platelet plug formation

3) Coagulation

What is INR?

International Normalised Ratio. Prothombin time (PT) - a blood test that takes how long it takes plasma in your blood to clot. Tests your blood vs average blood.

INR 1 is normal,

INR 2-3 is deep vein thrombosis,

INR >3.5 is prosthetic heart valve.

What is anaemia?

Condition where number of RBCs / haemoglobin conc is lower than normal in blood, so reduced capacity to transport oxygen.

Split into deficiency anaemia, where levels are too low, vs haemolytic anaemia, where the body is destroying them or they're weird (like sickle cell anaemia or thalassemia)

What are the main dental considerations for anaemia? (6)

1) If they have deficiency anaemia, they'll have ulcers, angular cheilitis and glossitis

2) If they have haemolytic anaemia, they'll have blood marrow hyperplasia and enlarged bones, pain and infections

3) Might need to adjust analgesics if they develop a tolerance

4) Splenectomy (removing spleen) will cause immune deficiency

5) ATB prophylaxis if they're doing major surgery

6) GA is dangerous if they have sickle cell anaemia

What is thrombocytopenia?

Where platelet count in blood is too low. Usually presents with petechiae and ecchymosis, haemorrhage and spontaneous bleeding.

What are the main dental considerations of thrombocytopenia? (6)

1) Spontaneous gingival bleeding

2) We can do normal procedures if they're simple

3) If extractions or surgery, be cautious

4) Can use platelet transfusions to replace

5) Local haemostatic measures are Desmopressin, Tranexamic Acid, and Topical platelet concentrates

6) If they get a splenectomy, can lead to infection.

What is haemophilia?

An inherited blood disorder where the blood coagulation factors are deficient. We see excessive and spontaneous bleeding, lots of blood. Split into different types of Haemophilia.

What is Haemophilia A?

Most common type, X-linked and affects males. Depends on trauma and Factor VIII coagulant. Will have spontaneous bleeding from childhood, etc.

How do we do dental management for haemophilia A? (9)

1) Use Desmopressin

2) Anti-fibrinolytic drugs, injected or IV

3) Factor VIII replacement

4) Avoid aspirin and NSAIDs

5) For anaesthesia, be careful - IANB and lingual infiltrations

6) Sedate with midazolam

7) Avoid sharp restorations

8) Local haemostatic measures and resorbable sutures

9) Surgery should be in a hospital

What is Haemophilia B, aka Christmas Disease?

AKA Christmas Disease, linked to Factor IX - mild bleeding, males affected but females are carried. Depends on Factor IX deficiency.

How do we do dental management for Haemophilia B / Christmas Disease? (8)

1) Factor IX replacement

2) Avoid aspirin and NSAIDs

3) Anti-fibrinolytic drugs, IV or oral

4) For anaesthesia, be careful - IANB and lingual infiltrations

5) Sedate with midazolam

6) Avoid sharp restorations

7) Local haemostatic measures and resorbable sutures

8) Surgery should be in a hospital

What is Haemophilia C, aka Von Willebrand's Disease (vWD) or Pseudohaemophilia?

Deficiency in Von WIllebrand Factor (vWF). Affects men and women, bleeding from mucosa, etc, purpura (purple colour) of mucosa and skin.

What are the dental considerations for Haemophilia C? (8)

1) Has spontaneous gingival bleeding

2) If we do normal and simple stuff, not associated wtih bleeding

3) Careful of extractios and surgeries

4) Bleeding risk even with mild haemophilia in more complex cases

5) If they're moderate or severe, consult with haemotologist

6) Use desmopressin and anti-fibrinolytic agents

7) Avoid NSAIDs

8) Use paracetamol with or without codein

What are neutrophil defects?

Split into leukopenia and neutropenia, which cause agranulocytosis (lack of white blood cells) as a symptom

Leukopenia: Low level of leukocytes

Neutropenia: Low level of neutrophils

What are the main dental considerations for neutrophil defects? (7)

1) Infections

2) Ulcers

3) Perio

4) Minor infections can cause .. gangrenous stomatitis, metastatic infections and septicaemia

5) Surgery done with ATBs

6) Risk of thrombocytopenia and haemorrhage

7) Risky to use corticosteroids

What are lymphomas?

Cancer of lymphatic system. Hodgking's Lymphoma, Non-Hodgkin's Lymphoma, others.

What are the main dental considerations of lymphomas? (6)

1) Cervical lymph nodes

2) Lumps or ulcers

3) Treatment is more complicated if we use corticosteroids or cytotoxic therapy

4) More likely to get infection and anaemia

5) Respiratory function will be worse because of radiation - they'll get pulmonary fibrosis

6) GA is Contraindicated

What are antithrombotic agents?

Medications that prevent blood clots, if someone is at a risk of thromboembolic events or has had one. Split into antiplatelets and anti-coagulants. Stops strokes, embolism and heart attack (infarct).

What simple measures should we do instead of using anti-thrombotic drugs if we see problems orally? (5)

Usually issues can be managed with local haemostatic measures, rather than drugs.

Simple measures include:

1) Pressure to wound with pad or 5% tranexamic acid

2) Haemostatic sponges made of fibrin or collagen

3) Sutures

4) Post-op instructions

5) Appointments should be at the start of the day (so we have more time to manage problems) and early in the week (in case problems recur after 24-48hrs)

How do we handle anaesthesia for anti-thrombotic agents? (3)

1) Avoid IM injections

2) Direct local anaesthesia infiltrative, or intraligamentary and intrapapillary are safe

3) Regional LA injections can cause bleeding into fascial spaces, same with floor of the mouth injections

What oral treatments can we do without worries of a thrombotic event? (4)

1) Supragingival scaling

2) Non-surgical endo

3) Removable and fixed prostheses

4) Direct restoration root planing

What are the main dental considerations of anti-thrombotic agents? (6)

1) Shouldn't stop them before procedures if it's biopsies, implant placement, perio surgery, endo etc.

2) Use haemostatic agents

3) If we need maxfax, refer to hospital

4) Anti-microbials can affect anti-coagulation. Avoid beta-lactams, ciprofloxacin, erythromycin and metronidazole

5) AVOID NSAIDs if they're taking any anti-thrombotics

6) Tramadol and Paracetamol can increase the effects of Warfarin

When do we give / take away heparin when it comes to dental treatment? (4)

1) If they're taking heparin, and we're doing an uncomplicated extraction of 1-3 teeth, don't make them stop

2) If advanced, consult with haematologist

3) If we stop heparin, we can do ANY surgery safely after 6-8 hours

4) If they're doing dialysis, surgery is better do on the day after dialysis

What are the problems we can encounter with Warfarin and VKAs? (4)

1) Surgery is the main hazard

2) Check their INR on the day of, or 24 hours before

3) ALWAYS consult with physician

4) To refer them to hospital, their INR must be more than 3.5, or an advanced surgery, or drug interactions with warfarin.

What are the main dental considerations for New Oral Anticoagulants (NOACs)?

1) They have short half lives

2) Local haemostatic measures are good

3) Can use NOAC therapy 4 hours after surgery