What's the process of haemostasis?
•Injury and tissue damage
•Platelet adhesion and aggregation
•Unstable platelet clot
•Coagulation factor cascade
•Fibrin (nat. anti-coag. controlled by
• Vascular response ---Vasoconstriction
• Platelet response :- VWF (Von Willebrand factor) +
platelet + fibrinogen ~ unstable platelet clot
• Fibrin (clotting cascade) gives stability to clot
What are the different types of coagulation defects?
• Haemophilia A,B,C, Von Willebrands
• Drugs: Warfarin, Heparin, Enoxaparin, Rivaroxaban,
Dabigatran, antiplatelet drugs
• Liver disease
• Vitamin K deficiency
• DIC (disseminated intravascular coag.)
• Massive blood transfusion
What is haemophilia A?
• Factor VIII deficient
Moderate 2-5 %
• Dental extractions and surgery are dangerous for
What is haemophilia B?
• Factor IX deficient
• Very similar to Haemophilia A but factor IX given instead of
• Factor IX has a longer half life so can be given daily
What is haemophilia C?
• Factor XI deficient
• Rapid fibrinolysis
• FFP, Factor XI plus tranexamic acid
What is vonWillebrands disease?
types 1(mild), 2, 3 (most symptomatic) & Pseudo VWD (platelet
• Similar to mild Haemophilia A
• Factor VIII infusion for more major procedures
DDAVP (Desmopressin) and oral tranexamic acid suitable for
more minor procedures
What is warfarin?
• Requires Active and regular monitoring via INR
• Warfarin usually takes 2-4 days to become effective
• Warfarin impairs synthesis of Vit. K dependent coagulant
factors (II,VII,IX,X) in the liver
How can you get acquired coagulation defects?
• Indications:- oral anticoagulation (short term)
• Prophylaxis to prevent DVT
• Myocardial infarction (3 months)
• Established DVT (3 months)
• Xenograft cardiac valves ( 3 Months)
• Pulmonary embolism (3-6 months)
• C.A.B.G. (2 months)
•Oral anticoagulation (long term)
•Recurrent venous thromboembolism
•Rheumatic heart disease and atrial
•Cardiac prosthetic valve replacement and
Potentiation of Warfarin: • Decreased synthesis of Vit.K dependent clotting factors
• Anti-platelet drugs
• Potentiating factors :- Antibiotics
-Miconazole oral gel
-Aspirin and NSAID’s
What are the different INR's for the different acquired coagulation defects?
• INR = Prothombin time (test)/PT (control)
• Normal 1
• DVT, PE, AF 2.5
• Recurrent DVT 3.5
• Recurrent PE 3.5
• Mechanical heart valves 3.5
• INR needs to be checked on the day of or no longer than 24-36 hrs prior to procedure (NPSA guidelines)
• Local measures need to be effective in regard to suturing and packing of wound with haemostatic agents
• Keep any procedure as “atraumatic” to the local tissues as possible
Some drug interactions?
-Anecdotal reports advise vigilance
-Single 3 gram dose not seen as a problem
-Should be avoided / (warfarin reduced by half)
-Unpredictable affects only certain patients
-Caution advised due to increased bleeding & GI bleeds
Daktarin Oral gel:
-Well described interaction
-INR of 20 reported resulting in death
How can the INR be altered before surgery (but not for routine dental procedures)?
INR can be altered if surgery planned by:
• Stopping 48 hrs prior to procedure
• Reducing warfarin by 50% for 48 hrs.
• “Patient may be compromised by reducing warfarin”
• INR may be altered/raised by administration of antibiotic course,
What are the new anticoagulants?
• Dabigatran etexilate (Pradaxa):
Direct thrombin inhibitor
• Apixaban (Eliquis):
Inhibitor of activated factor X
• Rivaroxaban (Xarelto):
Inhibitor of activated factor X
What are some antiplatelet medications?
• Low-dose aspirin (75-300mg daily)
What do aspirin, clopidogrel & ticlopidine do?
• Inhibit platelet aggregation to blood vessel walls.
• Last for the life of the platelets (7-10 days)
What does dipyridamole do?
• The effect is reversible acts directly on enzyme in platelets and vessel cell walls.
What are some non-steroidal antiinflammatory drugs?
•Ibuprofen / Diclofenac:
-Reversible effect once the drug is cleared
-Platelet function is restored.
-Are not used clinically for their antiplatelet
What should you be careful of with all the coagulation disorders?
• Regional blocks or injections in floor of mouth may cause
haemorrhage to track through tissue planes causing potential
• Factor VIII supplements must be given if there is any
likelihood of oral trauma. Immediately prior to procedure(^
• Avoid intramuscular injections
What is the normal bleeding time?
2-10 mins. Longer in women than in men.
What are some coagulation defects?
• Liver disease (leads to loss of the clotting factors produced by the liver)
• Hepatocellular failure (leads to loss of the clotting factors produced by the liver)
• Vit. K deficincy
• Increased fibrinolysis
What is the clotting cascade?
What is thrombocytopenia?
Lower than average platelet count. Normal platelet count is 150,000-400,000 platelets per microlitre of blood.
If platelet count below 100,000 some patients may experience symptoms such as bleeding often nosebleeds, and/or bleeding gums. Some women may have heavier or longer periods or breakthrough bleeding. Bruising, particularly purpura in the forearms, the difference is the bruises are caused from the inside. Petechia (pinpoint hemorrhages on skin and mucous membranes), which can be seen on feet and legs. Post op bleeding.
How do you manage thrombocytopenia?
• Autoimmune treat with steroids or splenectomy
• Leukaemia, aplastic anaemia, treat with platelet transfusion
• Important to get a full blood count prior to any invasive
• Use local measures
How can endocarditis be prevented?
• Not solely prophylactic but also requires adequate treatment of infection of bacteraemia and fungaemia
• Prompt removal of colonised devices / teeth
• Management of chronic conditions that can lead to repeated infection
What's the endocarditis prophylaxis for
• Good optimised oral hygeine
• Access to high-quality dental care
• Referral for dental assessment
• Treatment ideally at least 14 days before surgery to allow mucosal healing
• Emergency valve surgery
• Remedial treatment with definitive procedures 3 months post surgery
What antibiotic prophylaxis can be given to prevent endocarditis?
- Corsodyl mouthwash (chlorhexidine 0.2%) 10ml rinse at least 2 mins approx 2 mins pre-op
-Amoxyxillin 3g orally one hour pre-op
1gm IV 15 mins pre-op
-If alergic to amoxyxillin give clindamycin
What are the dental aspects of diabetes mellitus?
• Periodontal disease
• Lichenoid reaction with oral hypoglycaemics
• Sialosis +/- Xerostomia
What to do if patient becomes hypoglycaemic?
• 10g sugar ( 2 heaped teaspoons) as sweetened
• Hypostop gel
• Hypostop gel
• 50ml 20-50% dextrose IV
• 1mg Glucagon IM/SC