17.3 Management of dental patients taking anticoagulant and antiplatelet drugs Flashcards
Give examples of antiplatelets.
- Aspirin
- Clopidogrel
- Prasugrel
- Ticagrelor
NB: we never interrupt antiplatelet drugs for dental treatment.
What is the most common antiplatelet?
Aspirin
- 75mg OTC
- 150mg prescribed
We don’t stop aspirin for dental treatments
What is dual antiplatelet therapy?
For patients who have had an MI, they will be on dual therapy for 12 months- aspirin with clopidogrel/prasugrel/ticagrelor.
What is the ASA system?
Categorises the physical status of patients.
ASA 1 and 2 are treated in primary care.
Patients who have had a heart attack, stroke or ministroke in the past 3 months are classed as ASA 4.
Describe the action of warfarin.
Vitamin K anatognist
- Reduces liver’s production of clotting factors 2,7,9 and 10
What is the typical dose of warfarin?
1-10mg single dose per day (normally at night)
How long does warfarin take to reach its maximum effect?
48 hours
What is the normal INR for a healthy patient?
0.8-1.1
What is the typical INR target for a DVT patient?
2.2-2.5
What is the typical INR target for a pt with atrial fibrillation?
2.2-2.3
What is the typical INR target for a pt with recurrent DVT?
High e.g. 3 - 4
What is the INR limit for a dental extraction?
INR must be below 4
INR 4 and greater = high risk of catastrophic bleed
Should you ask a patient taking warfarin to change their dose for dental treatment?
No, never.
Name the 4 DOACs.
- Apixaban
- Rivaroxaban
- Dabigatran
- Edoxaban
Taken once or twice a day
Describe the action of DOACs.
- Apixaban, rivaroxaban and edoxaban are all factor Xa inhibitors
- Dabigatran is a direct thrombin inhibitor
What is clexane?
A LMWH (anticoagulant), used as a bridging therapy onto other anticoagulants.
Injected into pts admitted to hospital who are deemed high risk for a DVT.
Why may patients be taking anticoagulants or antiplatelets?
- Previous MI
- Previous CVA (cerebrovascular accident, stroke), TIA (transient ischaemic attack, mini stroke)
- Atrial fibrillation
- Ischemic heart disease
- DVT/PE
- Valvular heart disease, patients who have had mechanical or biological heart valve replacement
- Factor V Leiden syndrome, genetic condition
- Protein C deficiency, genetic
- Protein S deficiency, genetic
What is ischaemic heart disease?
Aka. coronary heart disease.
Condition where oxygen suppply does not meet the myocardial oxygen demand.
Give examples of ischaemic heart disease/coronary heart diseases.
What medication will patients with stable angina carry on themselves?
GTN spray, used sublingually.
Glyceryl trinitrate.
How does GTN spray work?
Causes vasodilation of BVs, thus increasing supply of oxygenated blood to the heart.
Can cause a headache.
What is the difference between stable and unstable angina?
Stable angina: central chest pain on exertion e.g. during exercise, which responds to rest or medication
Unstable angina: chest pain at rest or with minor exertion, doesn’t respond to medication or rest
What are STEMI and NSTEMI?
STEMI: myocardial infarction caused by complete occlusion of a major coronary artery
NSTEMI: myocardial infarction caused by a block in a minor artery or the partial obstruction of a major artery
Different ECG traces, treated differently.
What diagnostic test is used to confirm an MI?
Troponin
- Protein produced by breakdown of cardiac muscle
What should you do in dental practice if you suspect that a patient has an MI?
- Give GTN spray
- High flow oxygen via non-rebreathe mask at 15 litres
- Give aspirin
- Call 222
How long following an MI should a patient postpone routine dental treatment?
6 months
What type of anaesthesia may be indicated for previous MI patients who are anxious?
Sedation.
Stress can trigger cardiac events, sedation can prevent this.
What are the 2 types of valvular heart disease?
- Regurgitation: valves don’t close properly and blood leaks backwards, often occurs due to valve prolapse, can cause clots= increased stroke risk.
- Stenosis: valve flaps become thick/stiff. Results in narrowed opening and reduced blood flow through the heart.
What are the consequences of valvular heart disease?
- Heart failure
- Dyspnoea
- Chest pain
- Irregular pulse
- Syncope
What are the 2 types of valve replacements?
- Biological: tend to be for older patients
- Mechanical: tend to be for younger patients, require lifelong anticoagulants, last longer than biological replacement valves
What is a TAVI?
Transcatheter aortic valve implantation
- May see older patients with this
- Replacement valve with cow or pig tissue
- Minimally invasive
What is infective endocarditis?
A life threatneing infection of the endocardium of the heart.
Rare, affects less than 1 in every 10,000.
50% of pts have no underlying cardiac condition.
Which guidelines are followed with regards to antibiotic prophylaxis and infective endocarditis risk in dentistry?
SDCEP guidance
What patients are at a higher risk of IE?
- Acquired valvular heart disease with stenosis or regurgitation
- Hypertrophic cardiomyopathy
- Previous IE
- Structural congenital heat disease
- Valve replacement
Which sub-group of pts have been identified in the SDCEP guidance as potentially requiring antibiotic prophylaxis due to IE risk?
- Prothetic valve
- Previous IE
- Congenital heart disease
Abx for invasive dental procedures e.g. extractions, incision and drainage of abscess, flap raising, dental implants.
- Liaise with cariologist
- If not recommended by cardio team then follow advice for routine management
- Ensure consent is gained and recorded in notes
What abx do you prescribe for a high risk IE patient before dental treatment?
- 3g amoxicillin 60 minutes before procedure
Penicillin allergy:
- 600mg clindamycin (2 capsules) unless the cardiac team recommend an alternative
Why are dental procedures considered high risk for IE?
- Theory that bacteria from the mouth can enter the blood stream (bacteraemia) and colonise on the heart, causing IE
- Research has also found that even brushing your teeth can cause the same type of bacteraemia
- Poor evidence of what definitely causes a bacteraemia and what doesn’t
What are the signs and symptoms of IE that you should inform a patient to look out for and visit their GP?
Popular SBA question!
What BP is classed as hypertension?
> 140/90mmHg
What BP is classed as severely hypertensive?
> 160/100mmHg
What BP is classed as a hypertensive crisis?
> 200/100mmHg
Give examples of common antihypertensive drugs.
- Ramipril
- Amlodipine
- Lisinopril
What does hypertension put you at a higher risk for?
Thrombo-embolic events e.g. stroke, MI
What are the effects of sedative drugs on BP?
All sedative drugs cause hypotension.
Which BP reading is more important?
Systolic (top number)
What guidelines are followed for the management of dental patients taking anticoagulants or antiplatelets in dental practice?
SDCEP 2022
What is the general advice in the SDCEP 2022 guidance?
- Plan treatments for early in the day or week
- Use appropriate local measures
- Ensure haemostasis has been achieved before patient is discharged
When can DOAC medication be adjusted?
For higher bleeding risk dental procedures e.g. surgical extraction.
Pt taking apixaban twice a day- ask them to miss morning dose and take normal evening dose at least 4 hours post extraction.
DOAC medication interruption for dental treatment.