fibrinolytic therapy

FIBRINOLYTIC THERAPY

(Thrombolytic Therapy)

OBJECTIVES

Identify the indications for use in AMI Identify the indications for use in

acute non-hemorrhagic stroke Have knowledge of patient selection

criteria Have an enlarged scope of knowledge

with regard to fibrinolytics

INTRODUCTION

The goal of fibrinolytic therapy is to dissolve occlusive clots.

Thrombus occlusion leads to cessation of blood flow to the affected area leading to oxygen deprivation and tissue damage distal to the occlusion, leading to irreversible damage and possibly death.

THROMBOGENESIS

Traumatized tissue Activation of coagulation cascade

Thrombin Production of fibrinogen Fibrin

Fibrin strands cross-link and trap red blood cells and platelets

Clot is formed

FIBRINOLYSIS

Plasminogen activation Convert to Plasmin

Fibrin clot

Fibrinolytic therapy in AMI

Clot can be dissolved

Institute early Limits infarct size Preserve

myocardial function Decrease mortality

and morbidity

Patient selection criteria

Continuous CP lasting at least 30 min Symptom onset within 12 hours ST elevation in 2 contiguous leads CP unrelieved by NTG or nifedipine No absolute contraindications present Initiation of therapy can be prompt

Absolute Contraindications

Any hx of intracranial hemorrhage Known intracranial neoplasm or AV

malformation Suspected aortic dissection Active bleeding

General pre-fibrinolytic procedures

Obtain orders Explain to pt and

family Obtain informed

consent Baseline labs and

diagnostic tests At least 2 IV lines

Gather equipment:1. Phillips monitor2. Zoll at bedside3. Ambu bag ready4. Suction 5. Crash cart nearby6. Infusion pumps (3)

Tenecteplase (TNK)

Binds to fibrin and converts plasminogen to plasmin

Decreases circulating fibrinogen and plasminogen

TNK

Weight based One dose Reconstitute TNK vile with 10cc

sterile H2O Gently swirl Give single bolus over 5 seconds Maximum dose 50MG

TNK-Adverse reactions

Bleeding-internal or superficial

Reperfusion arrhythmias

Allergic rxn Coronary artery

re-occlusion

Surface Bleeding

Establish all peripheral IV sites prior to fibrinolytic infusion

Avoid IM injections Monitor all venous and arterial

sites frequently Apply direct pressure to all

bleeding for a minimum of 30 min. or homeostasis achieved

Coronary Artery Reperfusion

Normalization of the ST segment Resolution of the CP or ischemic

symptoms Reperfusion arrhythmias May not have any of the above

Reperfusion Arrhythmias

Bradycardia

V- tach

Heart Blocks

Eftifibatide (Integrilin)

A cyclic amino acid that binds to the platelet receptor glycoprotein GP IIb/IIIa of human platelets and inhibits platelet aggregation by preventing the binding of fibrinogen

Used in combination with heparin and ASA

Integrilin

Weight based dosing, use insert chart

Initial bolus 180mcg/kg-single dose over 1-2 minutes

Infusion of 2mcg/kg/min. Glass 100 ml bottle. Need vented spike

Refrigerated Option of low dose renal dose

Compatible With…

Alteplase Atropine Dobutamine

Heparin Lidocaine Metoprolol

Morphine Nitroglycerine

Verapamil

Tissue Plasminogen Activator (Activase,t-PA)

Activase binds to fibrin in a thrombus and converts the entrapped plasminogen to plasmin

Then initiates local fibrinolysis

Give within 3 hours of stroke s/s

Indications for MI

Lysis of thrombi obstruction in the coronary arteries

Reduction of infarct size Improvement of ventricular

function Reduction of incidence of CHF

Indications for stroke

Improve neurologic recovery Reduce incidence of disability

t-PA Reconstitution

Open Activase powder and 100cc sterile H2o

Using piercing pin, push into Activase vial

Attach sterile water bottle to top Allow the entire contents of water

to flow down , invert gently

t-PA Administration

Use a separate IV line, use IV pump Dosing different for stroke, pulmonary

emboli, CVAD occlusions, and AMI STROKE-0.9 mg/kg IV over one hour.

With 10% of the dose given IV push over one minute

Max dose is 90mg

T-PA for MI

100 mg over 90 min.

Bolus 15mg over 2 min.

Then 50 mg over 30 min.

Infuse last 35 mg over 60 min.

Heparin

Combines with other factors in the blood to inhibit the conversion of prothrombin to thrombin, and fibrinogen to fibrin

Adhesiveness of platelets is reduced

Well-established clots are not dissolved, growth is prevented and newer clots may be resolved

Heparin

Compatible with NTG and morphine at Y-site

Antidote – Protamine

sulfate

Nitroglycerin

A vascular smooth –muscle relaxant and vasodilator.

Affects arterial and venous beds

Reduces myocardial O2 consumption, preload and afterload

Nitroglycerin Administration

Glass bottle, vented spike

IV pump required. Given as mcg/min Usually 10-30mcg,

titrate to pain Lasts only 3-5

minutes

Compatible at Y-site with morphine and t-PA,heparin

Side effects: abdominal pain, allergic rxn, dizzy, HA, low BP

Metoprolol (Lopressor)

Cardioselective adrenergic blocking agent

Reduces incidence of recurrent MI Reduces size of the infarct and the

incidence of fatal arrhythmias Lasts 4 hours Contraindicated in HR < 45

Lopressor Administration

Five milligrams at five minute intervals to a total dose of 15 mg

Monitor rhythm, BP and HR between all doses

Hold for SBP less than 100 Compatible at Y-site with morphine

Concurrent Drugs

Aspirin

NTG sublingual

Lidocaine

Nifedipine

Door to drug time is

30 minutes