acute and chronic disorders that require anticoagulation therapy
MI, unstable angina, A-Fib, Indwelling devises such as indwelling heart valves, conditions in which blood flow may be slowed and blood may pool, such as major orthopedic surgery; also used in prevention of DVT
common disorders where anticoagulant therapy is contraindicated
Leukemia, pregnancy, gastrointestinal infection (colitis), recent surgery or other invasive medical procedures; also know drug allergies and acute bleeding risks as well as thrombocytopenia
major action and use of heparin
Works by binding to anti-thrombin III (AT-III) which turns off three main activating factors: Activated II (thrombin), activated X, and activated IX
-Mainly work to prevent the formation of a clot or thrombus
routes of administration for heparin and list appropriate nursing measures for each
IV and SQ ONLY!! Requires careful monitoring of PT/INR; Nurses also want to assess for adverse effects, such as bleeding. Nurses want to be mindful of drug interactions and other common adverse effects such as hematoma, nausea, anemia, thrombocytopenia, f
laboratory test that determines Heparin's effect
PT/INR
adverse effects of Heparin and list appropriate nursing action for each
-Bleeding, a hematoma at site of injection, nausea, anemia, fever, edema; Heparin induced thrombocytopenia (HIT), which is an allergic reaction mediated by the production of IgG antibodies
-Because of Heparins short half life (1 to 2 hours) stopping the t
Protamine Sulfate
the antagonist used to manage heparin toxicity
benefits of using low molecular weight heparin eg. Enoxaparin (Lovenox).
Lab monitoring isn't necessary because of its high bioavailability and greater affinity for factor Xa. It is available only in injection form.
Compare the action of Coumadin to Heparin in relation to the clotting process
-Heparins: Inhibit thrombin clotting factors.
-Coumadin: Inhibits vitamin K dependent clotting factors (available in PO form only).
Compare the onset and duration of action of parenteral and oral anticoagulants
Perenteral Anticoagulants - Onset Immediate (20-60min), Duration: Dose dependent
-Oral Anticoagulants - Onset: 12-24 hours, Duration: 2-5 Days
State the rationale for continuing parenteral anticoagulant therapy three days after starting oral therapy
Peak time for oral anticoagulant therapy is 3-4 days. Peak time for perenteral is 4-5hrs. The rational for continuing perenteral therapy is that it will take 3 days for the full effect of the oral therapy to take place.
lab test for determining the effect of Coumadin on the clotting process.
PTT
Vitamin K
List the antagonist for Coumadin
pertinent information to teach patients receiving either parenteral or oral anticoagulants
It is important to take meds at the same time every day. It is important inform them of bleeding precautions and to remember to follow up with doctor to monitor blood levels
the mechanism of action of the antiplatelet drugs
Mechanisms of action vary depending on the drug. Many of the antiplatelet drugs affect the cyclooxygenase pathway
-Prevents platelet plugs from forming, which can be beneficial in defending the body against heart attacks and strokes
three indications for the use of antiplatelet drugs
Aspirin recommended for stroke prevention
- Plavix reduces the risk of fatal and nonfatal thrombotic stroke
-Plavix also used as prophylaxis against transient ischemic attacks, as well as post - MI thromboprevention
the side effects, adverse effects and nursing responsibilities associated with the administration of antiplatelet drugs
Drowsiness, dizziness, confusion, flushing, nausea, vomiting, GI bleeding, diarrhea, heartburn; thrombocytopenia, leukemia, anemia, bleeding, rash and itching
--Should be constantly monitored for signs and symptoms of bleeding during and after use: epitax
the mechanism of action for the thrombolytic agents
Thrombolytic - used to break up existing thrombus
-Thrombolytics are coagulant modifiers that lyse the thrombi in the blood vessels that supply the heart with blood (coronary arteries). This reestablishes blood flow to the blood-starved heart muscle
Identify three indications for the use of the thrombolytics
Acute MI, Arterial Thrombosis, DVT, occlusion of shunts or catheters, PE, and acute ischemic stroke.
side effects, associated with the use of thrombolytics
Internal, intracranial and superficial bleeding. Also hypersensitivity, nausea, vomiting and hypertension
overdose with the use of thrombolytics
No specific antidotes; discontinue use, nurses should monitor vital signs, monitor for bleeding and take bleeding precautions
Anticoagulants
Used to keep the blood in the liquid state; chemicals that retard the tendency of the blood to become more viscous by natural post mortem processes or prevent any other adverse reactions from occurring between the blood and the other embalming chemicals.
Antifribinolytics
Drugs that prevent the lysis of fibrin and in doing so promote clot formation.
Antiplatelet drugs
decrease platelet's ability to stick together in the blood and form a clot, beneficial in preventing heart attacks and strokes.
Clot
Insoluble solid elements of the blood that have chemically separated from the liquid componets of the blood.
Coagulation
The process of blood clotting
Coagulation casade
The term used to describe the series of events that occur in the process of blood clotting
Intrinsic pathway
the process of forming a clot that doesn't require any tissue damage. The presence of platelets + Facrot XII + "activators" is enough to start this pathway.
Extrinsic pathway
process of hemostasis or blood clotting which is activated when the tissue is injured
DVT
Deep venous thrombosis
Embolus
a clot that breaks loose and travels through the bloodstream. When it causes sudden closure of a blood vessel, this dangerous event is an embolism.
Fibrin
Protein threads that form the basis of a blood clot
Fibrin specificity
Newer thrombolytic drugs actative the conversion of plasminogen into plasmin, only in the presence of an established clot having fibrin threads, rather than systemic plasminogen activation thru out the body.
Hemophilia
a group of hereditary bleeding disorders in which there is a defect in clotting factors necessary for the coagulation of blood
Hemorheologic drugs
Drugs that alter the function of platelets without compromising their blood clotting properties.
Hemostasis
the stoppage of bleeding
Hemostatic
a drug that stops the flow of blood within the vessels
Plasmin
enzyme formed from plasminogen that dissolves blood clots
Plasminogen
an inactive form of plasmin that occurs in plasma and is converted to plasmin by organic solvents
Pulmonary embolism
blockage of the pulmonary artery by foreign matter or by a blood clot
Stroke
a sudden loss of consciousness resulting when the rupture or occlusion of a blood vessel leads to oxygen lack in the brain
Thromboembolic events
Events in which a blood vessel is blocked by an embolus carried in the bloodstream from the site of it's formation. The tissue supplied by the blocked artery may tingle, become cold, numb, Cushitic, and eventually necrotic ( dead).
Thrombolytic drugs
Dissolve B. Examples of Drugs 1. Alteplase (tissue plasminogen activator recombinant, tPA, Activase) 2. Streptokinase 3. Urokinase C. Indications 1. MI 2. Strokes 3. Pulmonary embolus 4. DVT D. Side effects / nursing care 1. Bleeding 2. Heparin therapy ma
Thrombus
a blood clot formed within a blood vessel and remaining attached to its place of origin
Tissue plasminogen activator
a thrombolytic agent (trade name Activase) that causes fibrinolysis at the site of a blood clot.
Fibrinogen
A blood protein essential to blood clotting. The conversion of fibrinogen to its active form (fibrin) is among the final steps in clot formation, and is triggered by thrombin.
Anticoagulants
Prevent coagulation.
Haparins: requires blood level monitoring
LMWH: do not require blood tests, both inhibit thrombin
Coumarins (warfarin) inhibit vit k clotting factors.
Adverse affects: bleeding
Antiplatelets
Interfere with platelet function.
Plavix
Antifibrolytics
Prevent the lysis of fibrin, promotes clot formation.
Thrombolytics
Dissolves of preformed clot.
Activase
Coumarin dosage
Oral drug, 2-10mg day, pt or INR determines maintenance dose.
Heparin dosage
IV or SC; test w/ PTT (protamine sulfate is antidote); dosage is in UNITS
5000 units SC prophalaxis. IV infusion 20,000-40,000 units/ day.
Lovenox dosage
SC 30-40 mg every 12 hrs. For prophylaxis
activated partial thromboplastin time
aPPT blood test used to determin how long it takes clots to form to regulate heparin dosage
International Normalized Ratio
INR; a more consistant measure of coagulation for coagulation studies regardless of thromboplastin reagent used. Accepted from World Health Organization; makes results not dependent upon reagent used. Used for PT/INR studies usually for monitoring patient