Question

Oxygenation, Perfusion, fluid and electrolytes are concepts reflect normal physiological mechanism occurring inside the human body which may be affected by the pathological conditions and at the same time can lead to new pathological one.

Perfusion concept and apply it on pulmonary embolism showing the following:

1. Introduction about the selected concept(s)
2. Brief introduction about pulmonary embolism
3. Focus on the physiological changes on the selected concept(s) associated with pulmonary embolism in relation to:

1. Clinical S & S
2. Diagnostic measures
3. Management (medical, surgical & nursing management).

Answer 1

Perfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue.

Gas exchange occurs in the lungs between alveolar air and blood of the pulmonary capillaries. For effective gas exchange to occur, alveoli must be ventilated and perfused. Ventilation refers to the flow of air into and out of the alveoli, while perfusion refers to the flow of blood to alveolar capillaries.

Pulmonary embolism is a blockage in one of the pulmonary arteries in the lungs. In most cases, pulmonary embolism is caused by blood clots that travel to the lungs from deep veins in the legs or, rarely, from veins in other parts of the body (deep vein thrombosis).

resulting in a redistribution of blood to the non-occluded vessels. This leads to ventilation/perfusion (V/Q) matching abnormalities which includes extremely high or infinite V/Q values in the embolized region(s) but also potentially decreased V/Q units in the non-occluded tissue, hence impaired gas exchange, hypoxemia and hypocapnia can result.

Pulmonary embolidm typically sudden in onset and may include one or many of the following: dyspnea (shortness of breath), tachypnea (rapid breathing), chest pain of a "pleuritic" nature (worsened by breathing), cough and hemoptysis (coughing up blood).More severe cases can include signs such as cyanosis (blue discoloration, usually of the lips and fingers), collapse, and circulatory instability because of decreased blood flow through the lungs and into the left side of the heart.

Diagnosis of patient with PE includes the physical examination to rule out the DVT. Any signs of DVT like different calf girth of the legs. chest X-ray or an ultrasound scan to see if you have a blood clot in your leg, and tests to check how well your lungs are working.basrd on assessment other specialized tests

1.blood test to look for a protein called D-dimer. High levels of D-dimer in your blood suggest that pieces of blood clot are loose in your bloodstream.
2.a computerised tomography pulmonary angiography (CTPA) to see the blood vessels in your lungs. injected with a dye that helps to show your blood vessels and a scanner uses X-rays to build a detailed picture of the blood flow in your lungs.
3.a ventilation-perfusion scan, also called a V/Q scan or isotope lung scanning, to examine the flow of air and blood in your lungs. If the scan shows parts of your lungs have air in them but no blood supply, this may be the result of a pulmonary embolism.

4.leg vein ultrasound to confirm you have a clot in the leg.

5.MRI

Management

Treatment of pulmonary embolism is aimed at keeping the blood clot from getting bigger and preventing new clots from forming. Prompt treatment is essential to prevent serious complications or death.

Medications
Medications include different types of blood thinners and clot dissolvers.

Blood thinners (anticoagulants). These drugs prevent existing clots from enlarging and new clots from forming while your body works to break up the clots. Heparin is a frequently used anticoagulant that can be given through the vein or injected under the skin. It acts quickly and is often overlapped for several days with an oral anticoagulant, such as warfarin, until it becomes effective, which can take days.

Clot dissolvers (thrombolytics). While clots usually dissolve on their own, sometimes thrombolytics given through the vein can dissolve clots quickly. Because these clot-busting drugs can cause sudden and severe bleeding, they usually are reserved for life-threatening situations.they are tenectiplase, alteplase, Urokinase, streptokinase.

Surgical and other procedures
1.Clot removal. If have a very large, life-threatening clot in the lung, doctor may suggest removing it via a thin, flexible tube (catheter) threaded through blood vessels.
2.Vein filter. A catheter can also be used to position a filter in the body's main vein (inferior vena cava) that leads from your legs to the right side of the heart. This filter can help keep clots from going to your lungs. This procedure is typically reserved for people who can't take anticoagulant drugs or when they have had recurrent clots despite use of anticoagulants. Some filters can be removed when no longer needed.

3.Interrupting the vena cava. This approach prevents dislodged thrombi from being swept into the lungs while allowing adequate blood flow.

Nursing management

Nursing care for a patient with pulmonary embolism includes:

1.Prevent venous stasis. Encourage ambulation and active and passive leg exercises to prevent venous stasis.
2.Monitor thrombolytic therapy. Monitoring thrombolytic and anticoagulant therapy through INR or PTT.
3.Manage pain. Turn patient frequently and reposition to improve ventilation-perfusion ratio.
4.Manage oxygen therapy. Assess for signs of hypoxemia and monitor the pulse oximetry values.
5.Relieve anxiety. Encourage the patient to talk about any fears or concerns related to this frightening episode.