Clotting Disorders
-Thrombogenesis
-Atherosclerosis
Thrombogenesis
-normal body defense
-becomes pathogenic when causes vascular obstruction; section that breaks off and travels is the embolus
Hemostasis
-prevention or stoppage of blood loss from an injured vessel (maintains vascular compartment integrity)
Hemostasis Mechanisms
-vasoconstriction
-formation of platelet plug
-sequential activation of clotting factors
-reparation of the opening in damaged vessel
Atherosclerosis
-can affect any organ or tissue
-often involves arteries supplying: heart, brain, legs
-consequences and clinical implications depend on location and size of thrombus/embolus
Heart
thrombus may precipitate MI
Brain
thrombus may precipitate stroke
Legs
thrombus may precipitate DVT
Arterial Thrombosis
-Atherosclerotic plague, HTN
-turbulent blood flow damages arterial endothelium and activates platelets to initiate coagulation
-cause disease by blood flow obstruction: ischemia, infarction
Venous Thrombosis
-associated with venous stasis
-less cohesive than arterial thrombus: venous embolus more likely to detach and travel
-causes diseases via DVT and embolization
Coagulation pathways
-coagulation process that generates thrombin consists of 2 interrelated pathways
-extrinsic and intrinsic
Extrinsic Pathway
initiated by the activation of clotting factor VII and the release of thromboplastin
Intrinsic Pathway
triggered when blood comes in contact with exposed collagen fibers in the sub-endothelium of damaged blood vessels
Anticoagulants
-used in thrombotic disorders
-Heparins (lmwh)
-vitamin K antagonist (warafin)
Antiplatelets
-used to prevent arterial thrombosis
-Ibuprofen and other NSAIDS
-Aspirin
-Clopidogrel
Thrombolytics
-dissolve thrombi and limits tissue damage in thromboembolic disorders
-streptokinase
-urokinase
-enoxaparan
Urokinase
type plasminogen activator
Enoxaparan
tissue-type plasminogen activator
Anticoagulants
-given to prevent new clot formation and extension of clots present
-they DO NOT: dissolve formed clots, improve blood flow around clot, prevent ischemic damage beyond clot
-indications for use: prevention or management of thromboembolic disorders; thromb
Indications for Anticoagulant therapy
-prevention and treatment of DVT
-treatment of pulmonary embolism
-prevention of stroke in patients with AF, artificial heart valves, established thrombosis (DVT, cardiac)
-ischemic heart disease
-during procedures such as cardiac catheterization
-all mus
Heparin
Prototype: Heparin
Indications: drug-drug any drugs that affect platelet function. Drug-natural: inc risk of bleeding with large amounts of anise and chamomile
Pregnancy: C
Heparin action
blocks conversion of fibrinogen to fibrin
Heparin Indication
-prophylaxis and treatment of thromboembolic disorders
-venous clots, PE, A- fib with embolization
-in very low doses, used to maintain potency of certain IV catheters
Heparin Contraindications
-hypersensitivity
-bleeding disorders or severe bleeding
-severe thrombocytopenia
Heparin SE
-hemorrhage from any body site
-tissue irritation and pain at injection site
-anemia
-thrombocytopenia/HIT
-fever
Heparin Assessment
-monitor aPTT should be 1.5- .25 times the control (20-39 seconds) without signs of hehmmorage
-monitor platelet count every 2-3 days during therapy, usually low 4th day and resolves, but HITT can develop around day 8
-check for s/s of hemorrhage: bleedin
Heparin Administration IV
-fatal hemorrhages have occurred
-check y site compatibility
-continuous drip must be reviewed independently and checked off by another nurse
-for IV flush, be sure correct dilution. 10-1000 units, flush with NS first
Heparin Administration SQ (never IM)
-only one route is ordered
-cannot be used interchangeably with regular heparin
-admin deep into SQ tissue
-alternate injection sites daily
-abdominal wall, upper thigh, buttocks, holding fold of skin
-do not aspirate or massage
-for enoxoparin, do not ex
Heparin Patient Teaching
-use electric shaver and soft toothbrush
-let nurse know if there is bleeding gums, brushing, nosebleeds, black or tarry stools
-do NOT take aspirin or NSAIDS
-should have a wallet cord or med alert bracelet
Heparin Safety Measures
-if aPTT > value specified in hospital policy: hold heparin in a hour, tell HCP, repeat aPTT, monitor patients for s/s of bleeding
-dosing is typically weight based
Protamine Sulfate
-heparin antidote
-can be given to reverse IV or Subq heparin
-assess for allergy to furs or any previous reactions to this drug
-assess for s/s hypersensitivity reaction, keep epinephrine and resuscitation equipment close by
-assess for hemorrhage; rebou
HIT
-heparin induced thrombocytopenia is an important and life threatening complication
-suspect when a patient has a fall in a thrombocyte count while receiving heparin
-immune-mediated adverse reaction
-1-3% of those who receive heparin for 4-14 days develo
LMWH
-low molecular weight heparin
-Dalteparin, Enoxaparin
-do not require close monitoring of blood coat levels
-works well for outpatient
-associated with less thrombocytopenia than regular heparin, although platelets still need to be monitored
Vitamin K antagonists
-warafin is an oral med that provides anticoagulation by inhibiting effects of vitamin K on clotting factors ( II, VII, IX, X)
-takes 48 hours before this has a measurable effect on coagulation
-heparin should be started initially, while a patients is bei
Vitamin K antagonist Prototype
Prototype: Warfarin (Coumadin)
-lower doses in asian or geriatric patients
-Pregnancy: X
-QSEN: monitor INR, in absence of INR protocol, hold INR > 3
-BBW: risk of causing major or fatal bleeding
Warfarin Indications
-most often in prophylaxis and treatment of venous thromboembolic disorders
-DVT
-PE
-Myocardial Infarction
-prevention of clots after prosthetic valve replacement
-atrial fibrillation
Warfarin Action
-interferes with hepatic synthesis of vitamin K dependent clotting factors
Warfarin Contraindications
-active GI ulcer disease
-recent surgery of the eye, spinal cord, brain
-blood disorders associated with bleeding
-geriatric patients should be on reduced doses due to inc drug effect
-pregnant crosses placenta and may produce fatal fetal hemorrhage
Warfarin SE
-hemorrhage in external gums, trauma, IV site
-internal hemorrhage GI, brain
Warfarin Interactions
-Drug-drug: many including chronic alcohol intake
-Drug-food: ingestion of large quantities of foods high in vitamin K can antagonist the anticoagulant effect. dec effect of drug: asparagus, broccoli, brussel sprouts, green leafy veggies
-Drug-food: foods
Warfarin Assessment
-assess PT and INR daily
-assess for reduction of s/s of thrombotic disorders, DVT with less calf pain, less warmth and edema
-assess for bleeding gums, incisions or IV sites, blood in stock, bruising, nosebleeds, especially in elderly
Warfarin Administration
-requires 3-5 days to reach effective levels, started while patient is on heparin
-same time each day
Warfarin Patient teaching
-once discharged on therapeutic warafin level, must have blood drawn at lab every 2-4 weeks
-once blood drawn, will need constant pressure on site for approx 5 minutes
-use electric shaver, soft toothbrush, no flossing
-report any usual bleeding or bruisi
Vitamin K
-warfarin antidote
-aka, Phytonadione, Mephyton
-admin with INR > 5: hold warfarin, notify HCP, anticipate
-if bleeding present, monitor for shock
Other Oral Anticoagulant Drugs
-Dabigatran, Rivaroxaban, Apixaban, Ximelagatran
-Used to treat A-fib, DVT,PE after treatment of parenteral anticoagulants from 5-10 days
-frequent lab testing is NOT needed
Anti platelet Drugs
-prevent one or more steps in prothrombic activity of platelets
-act by inhibiting platelet activation, platelet adhesion, platelet aggregation, procoagulant activity
-AE: depend on med used
Anti platelet Prototype
Prototype: Clopidogrel
Other: Aspirin
-no antidote exists
-BBW: some patients are reduced metabolizers
Clopidogrel Action
inhibits platelet aggregation
Clopidogrel Indications
-reduction of MI and stroke for patients at risk for patients at risk due to recent MI, acute coronary syndrome, stroke, or PVD
-atrial fibrillation who are unable to take warfarin
-after placement of cardiac stents
Clopidogrel Patient Teaching
-may be taken with or without food
-many drugs increase or decrease the effect
Thrombolytic Agents
-given to dissolve acute life threatening clots in MI
-clot busters in patients younger than 80
-goal is to reestablish blood flow as quickly as possible, prevent/limit tissue damage
-AE: bleeding
Use of Thrombolytic Agents
-acute myocardial infarction
-acute pulmonary embolism
-ilio-femoral thrombosis
-acute ischemic strokes
Thrombolytic Agents Prototype
Prototype: Alteplase (Activase) aka Tissue plasminogen activator
Alteplase Action
-stimulate conversion of plasminogen to plasmin (breaks down fibrin) breaks down clots
Alteplase Assessment
-careful assessment of patient for bleeding every 15 minutes during first hour
-check line sites and neuro status
-assess for s/s of hypersensitivity
Thrombolytic Therapy
-only by experienced personnel in ER or ICU in diagnostic/interventional setting with cardiac monitoring in place
-labs (INR, aPTT, Platelets, fibrinogen) needed pre admin
-factors in bleeding decrease include careful selection of recipients, avoiding inv
Post Thrombolytic Concerns
-Bleeding: symptomatic brain hemorrhage, informed consent must be signed
-watch heart for cardiac arrhythmias
-avoid fun line
-use electric shaving
Med Management
-Heparin: regulated by aPTT
-Warfarin: regulated by INR based on PT
-Platelets should be 150,000-450,000. If less than 100,000 med must be discontinued.