ARTERIAL EMBOLISM

Definition of Arterial Embolism and thrombosis

·         Thrombus is a stationary clot.

·         Thrombosis is a state in which a clot has formed within a blood vessel.

·         Phlebothrombosis is development of a clot within a vein without inflammation.

·         Embolus is moving mass (clot) of particles either solid or gas within the blood stream.

Predisposing factors

• Acute arterial occlusions may result from iatrogenic injury, which can occur during insertion of invasive catheters such as those used for arteriography,

• Other causes include trauma from a fracture,

• Crush injury
• Penetrating wounds that disrupt the arterial intima.

·         Immobility

Pathophysiology

·         Thrombosis in the venous system occurs in the lower extremities and generally associated with disorders or a circumstance that causes venous stasis such as inactivity, immobility, trauma to a blood vessel commonly predispose to clot formation. When a thrombus forms or an embolus reaches a blood vessel that is too small to permit its passage there is partial or total occlusion of blood flow through vessel leading to signs and symptoms.

OR

Arterial emboli arise most commonly from thrombi that develop in the chambers of the heart as a result of atrial fibrillation, myocardial infarction, infective endocarditis, or chronic heart failure.

These thrombi become detached and are carried from the left side of the heart into the arterial system, where they lodge in and obstruct an artery that is smaller than the embolus.

Emboli may also develop in advanced aortic atherosclerosis because the atheromatous plaques ulcerate or become rough

Acute thrombosis frequently occurs in patients with preexisting ischemic symptoms.

Signs and Symptoms

• The extremity suddenly becomes white, poikilothermia (coldness), and paralysis. and extremely painful

·         Arterial pulsation become absent

·         Numbness, tingling or cramping may be present

·         Loss of sensation

·         Loss of the ability to move

·         Tissue necrosis

·         If small vessels obstructed symptoms are less severe.

Deep vein thrombosis

Signs and symptoms include:

o   Pain

o   Swelling

o   Tenderness of the affected extremity

o   Mild fever

Diagnosis of the condition

o   Arteiography or Venography (also called phlebography)

o   Angiography of the affected extremity  or organ

o   Doppler ultrasound

o   Duplex Doppler Ultrasound exam of extremity

o   Echocardiogram

o   MRI

o   Myocardial contrast echocardiography (MCE)

o   Plethysmography

o   Transcranial Doppler exam of arteries of brain

o   Transesophageal echocardiography (TEE) all this study may reveal underlying cardiac disease.

Medical and Surgical Treatment

Treatments depend on whether vein or artery is occluded and degree of occlusion.

·         Arterial occlussion

o   Heparin  is given Intravenously immediately to prevent development of further clots

o   Vasodilative  drugs to improve circulation

o   Sympathetic nerve block to relieve vasospasm.

o   Nacortics may be given to relieve pain and client’s apprehension.

o   A thromboliytic agent may be prescribed

o   A thrombectomy , embolectomy, endarterectomy(removal of the lining of an artery)

o   Insertion of  bypass graft  is necessary.

• Bypass of the artery (arterial bypass) to create a second source of blood supply
• Clot aspiration (thromboaspiration)
• Clot removal through a balloon catheter placed into the affected artery or through open surgery on the artery (embolectomy)
• Opening of the artery with a balloon catheter (angioplasty) with or without a stent implanted

·         Venous occlusion

o   Back rest,

o   Elevation of extremity

o   Local heat ,

o   Analgesics for pain and intermittent subcutaneous heparin(anticoagulant)therapy.

o   Oral anticoagulant may be given

o   Thrombectomy may be done.

Nursing management

·         Establish an increase in arterial or venous blood flow

·         Give analgesics to relieve pain and discomfort.

·         Monitor the intravenous infusion Heparin hourly or give heparin subcutaneously on the abdomen

·         Before surgery, the patient remains on bed rest with the extremity level or slightly dependent (15 degrees).

·         The affected part is kept at room temperature and protected from trauma. Heating and cooling pads are contraindicated because ischemic extremities are easily traumatized by alterations in temperature.

·         If possible, tape and electrocardiogram electrodes should not be used on the extremity; sheepskin and foot cradles are used to protect the leg from mechanical trauma

·         If the patient is treated with thrombolytic therapy, she or he is accurately weighed in kilograms, and the dose of thrombolytic therapy is determined based on the patient’s weight.

·         The patient is admitted to a critical care unit for continuous monitoring. Vital signs are taken every 15 minutes for 2 hours, then every 30 minutes for the next 6 hours, and then every hour for 16 hours.

·         Bleeding is the most common side effect of thrombolytic therapy, and the patient is closely monitored for any signs of bleeding.

·         The nurse also minimizes the number of punctures for inserting intravenous lines, avoids intramuscular injections, prevents any possible tissue trauma, and applies pressure at least twice as long as usual after any puncture that is performed.

·         During the postoperative period, the nurse collaborates with the surgeon about the patient’s appropriate activity level based on the patient’s condition.

·         Generally, every effort is made to encourage the patient to move the leg to stimulate circulation and prevent stasis.

·         Anticoagulant therapy may be continued after surgery to prevent thrombosis of the affected artery and to diminish the development of subsequent thrombi at the initiating site.

·         The nurse assesses for evidence of local and systemic hemorrhage, including mental status changes, which can occur when anticoagulants are administered.