Coagulation and Hyperlipidemia Flashcards
What is hemostasis?
Blood coagulation
What is thrombogenesis?
Overactive clotting which can lead to thrombus formation and thus vessel occlusion
Why is blood coagulation important?
It is needed to prevent excessive hemorrhage from a damaged blood vessel- inadequate blood clotting leads to excessive blood loss
What influences hemostasis?
Hyperlipidemia- excessive plasma lipids
Why is lowering plasma lipid levels important?
to prevent atherosclerosis- done through medications in conjunction with lifestyle modifications
How is a blood clot broken down?
through t-PA (tissue plasminogen activator)- which converts plasminogen to plasmin
-plasmin is an enzyme that directly breaks down the fibrin mesh and destroys the clot
-a fibrinolytic that is given through IV
-successfully treats MIs
What is the framework of a blood clot?
strands of fibrin bound together to form a meshlike structure
What are the drugs to treat blood clots?
- Anticoagulants: To control the synthesis and function of clotting factors
- Antiplatelets
- Fibrinolytics
What are anticoagulants used for?
Used to prevent and treat clots in the venous system: treats venous thrombosis, thromboembolisms and prophylactically for those at risk for DVTs
What is the primary anticoagulant for initial treatment?
Heparin- the initial treatment of venous thrombosis b/c effects are seen almost immediately
-given parenterally: IV
-administered 2+ times/day
What has replaced the use of traditional heparin?
Low Molecular Weight Heparin- Lovenox
-administered as a subcutaneous injection into fat tissue
-1x/day at home
When is low molecular weight heparin typically used?
For those having surgery, those at risk for DVTs and used for several weeks following discharge from hospital
What is the primary anticoagulant for long-term prevention?
Coumadin (Wardarin)- interferes with vitamin K metabolism in the liver which impairs the hepatic synthesis of several clotting factors
-administered orally
-takes several days to be effective
**patients must be monitored to ensure is it at a therapeutic dose
What is the acceptable clotting INR range?
2-3
Side effects of anticoagulants
-Hemorrhage: increased bleeding, blood in stool or urine, bleeding gums, heavy menstrual flow
-Thrombocytopenia: decreases platelets
-GI distress
-Skin reactions
What do anti-platelet drugs do?
Prevent excessive clotting caused by increased platelet activity
-primarily prevents arterial clots
Which antiplatelet drugs suppresses natural platelet aggregation?
Aspirin- prevents platelet induced thrombosis
-reaches a platelet and inhibits it for the remainder of its life (7-8 days) (irreversible)
What does aspirin help with?
-prevents ischemic stroke
-used to prevent DVT (used an in adjunct to heparin or warfain to treat DVTs)
Risk of aspirin
May increase risk for hemorrhagic stroke
What is ADP?
Adenosine diphosphate- a chemical that increases platelet activity and platelet induced clotting
How do ADP receptor blockers work?
Block the ADP receptor which reduces clotting
What are ADP receptor blockers used for?
used primarily to prevent thrombosis in patients who are at risk for an MI or ischemic stroke:
-pts with unstable angina
-pts with a-fib
How do glycoprotein IIB-IIIa receptor blockers work?
these drugs inhibit the ability of fibrinogen to activate platelets by blocking the receptor site on the platelet membrane which reduces platelet induced clotting
Which drugs are the most powerful inhibitors of platelet activity?
Glycoprotein IIb-IIIa receptor blockers- used to prevent thrombosis in those undergoing angioplasty and other interventions
Side effects of antiplatelet drugs
-increased risk of bleeding
-hypotension
-GI distress
Aspirin:
-gastric irritation
-toxicity to liver and kidneys at high doses
What do fibrinolytics do?
facilitate the breakdown and helps to dissolve clots that have already formed- used to reopen blood vessels
What are fibrinolytics mostly used for?
Essential in treating those with MI
-re-establishes blood flow when used at onset of MI
-decreases morbidity and mortality following an MI
-administered one hour within onset of MI reduces mortality by 50%
-via IV into systemic circulation
Other uses for fibrinolytics
-used to dissolve clots in peripheral arteries: femoral, popliteal)
-used to dissolve DVTs
-used for PEs
-used to treat shunts and bypass grafts
Risk factors for fibrinolytics
intracranial hemorrhage or other bleeding problems
Contraindications for Fibrinolytics
-history of hemorrhagic stroke
-active internal bleeding
-other factors that would create an increased risk for hemorrhage
Adverse effects of fibrinolytics
-hemorrhage
-excessive bleeding during wound care dressing changes
-itching
-nausea
-HA
-allergic reaction
What is hemophilia?
unable to synthesize adequate amounts of specific clotting factors
-pts develop joint problems due to intra-articular bleeding
treatment of hemophilia
Missing clotting factors need to be replaced- done prophylactically or acutely
Treatment of insufficient vitamin K
The liver needs adequate vitamin K to produce clotting factors- admnistration of exogenous vitamin K can resolve this
What is hyperlipidemia?
Abnormally high concentrations of lipids in the blood- this causes atherosclerosis
What is the primary cause of cardiovascular disease?
hyperlipidemia
The different types of lipids in the blood
- high density lipoproteins (HDL): good cholesterol
- low density lipoproteins (LDL): bad cholesterol
- Triglycerides: type of lipid (fat)
Treatment of hyperlipidemia
Focuses on increasing HDLs and lowering LDLs
-meds used when this cannot be achieved through lifestyle modifications
-examples: satin drugs and fibric acids
What do satin drugs do?
They reduce cholesterol production especially in liver cells which causes a breakdown in LDL and a decrease in triglycerides and an increase in HDL levels
-decrease mortality and morbidity in those with high cholesterol
Which drugs are the mainstay in treating cardiovascular disease and may have anti-cancer effects?
statin drugs
What do fibric acids do?
They decrease triglyceride levels
-may produce an increase in HDL levels and help lower LDL levels
adverse effects of lipid lowering drugs
-GI distress
-liver dysfunction, gallstones, pancreatitis
-cardiovascular problems: arrhythmias
-neuromuscular problems (statin drugs): myopathy that can progress to rhabdomyolosis if not caught early
Rehab implications for anticoagulants
-primary problem is increased risk of bleeding (careful with wound care and aggressive manual techniques)
-be aware of signs of intra-joint bleeding (hemophilia)
rehab implications for hyperlipidemia
Pts need to be educated on nonpharmacological methods at managing their cholesterol (diet, exercise)
