1 - Bleeding Flashcards
What is the second most numerous cell in the bloodstream, and how often is it replaced by the body?
Platelets - every 10 days
Where are clotting factors synthesized?
In the liver
What is necessary for the synthesis of 4 clotting factors? What are they?
Vitamin K
Factors II, VII, IX, X
Protein C and S
What is heparin primarily secreted by?
- Mast cells & basophils
Where do clots on the left and right side lodge?
- Left side of body
- Blocks arterioles - ischemia to organs
- Right side of body
- Pulmonary arteries to lungs - pulmonary embolism (PE)
Why is bacterial endocarditis treated with both antibiotics and anticoagulants?
Because circulating bacteria and their endotoxins activate clotting = septic shock
What are the clotting cascade steps?
- Prothrombin
- Thrombin
- Fibrinogen
- Fibrin
What is the leading cause of re-hospitalization following joint replacement surgery?
Deep vein thrombosis and Pulmonary embolism
What are anti-platelet drugs used for?
- To reduce the risk of stroke and other adverse thromboembolic events
What is a percutaneous coronary intervention (PCI)?
Stent - bare-metal and drug-eluting stents
Optimal treatment for many patients experiencing acute coronary syndromes
Aspirin along with antiplatelets do what to platelets?
Cause irreversible effects
What is the most comprehensively studied and least expensive of all antiplatelet medications?
Aspirin - acetylsalicyclic acid (ASA)
In dentistry - what is the drug for MI treatment for patients having a heart attack for pre-hospital admission?
Aspirin - 325 mg full strength, 81 mg low dose
If there is a well-documented and justifiable need to discontinue aspirin before dental treatment, wait at least ______ prior to invasive surgical procedures.
1 week - it allows for platelet turnover
What does discontinuing the use of aspirin suddenly do?
Increases mortality risk - 3 fold higher risk
Even higher in pts with coronary stents - by a factor of 89
What older antiplatelet drug can be used with warfarin to decrease thrombosis following placement of artificial heart valves?
dipyridamole (Persantine)
What antiplatelet drugs fall under the category of Theinopyridines?
- ticlopidine (Ticlid)
- clopidogrel (Plavix)
- prasugrel (Effient) - new drug in 2009
What drug is used for those who are intolerant to aspirin, and coronary stent implantation has taken place?
ticlopidine (Ticlid)
- lowers risk of stent thrombosis
What drug prevents the binding of ADP to collagen receptors which prevents platelet aggregation?
clopidogrel (Plavix)
- Replaced use of ticlopidine, better safety-tolerance profile
What are the indications for clopidogrel (Plavix)?
- Reduce rate of TE (MI, stroke, vascular death) in pts with recent MI or stroke
- Reduce rate of TE in pts with unstable angina managed medically or with PCI
What is the main course of action of theinopyridines?
Inhibit the ability of adenosine diphosphate (ADP_ to induce platelet aggregation – irreversible effect
What is the US boxed warning on prasugrel (Effient)?
May cause significant or fatal bleeding - contraindicated in pts with active pathological bleeding or history of TIA or stroke.
What are the 3 recommendations from advisory statement concerning disconinuation of anti-platelets?
- Consult cardiologist to discuss optimal pt management strategies
- Elective procedures with risk of bleeding should be deferred until pt has completed appropriate course of thienopyridine therapy
- 12 months after DES implant (stent)
- Minimun 1 month for bare-metal stent
- Pts with DES who have procedures, aspirin should be continued - restart thienopyridine asap
What are platelet glycoprotein IIb/IIIa receptor antagonists (fibrinogen receptor inhibitors) used for?
Used with aspirin and heparin to treat acute coronary syndromes via IV infusion
