A 57 year old man undergoes total knee replacement for severe degenerative joint disease. four days after surgery, he develops an acute onset of shortness off breath and right-sided pleuritic chest pain. He is now in moderate respiratory distress with a respiratory rate of 28 breaths per minute, heart rate of 120 bpm, blood pressure of 110/70 mm Hg. Oxygen saturation is 90%. Lung examination is normal. Cardiac examination reveals tachycardia but is otherwise unremarkable. The right lower extremity is post surgical, healing well and 2+ pitting edema, calf tenderness, erythema, an warmth; the left leg is normal. He has a positive Homan sign on the right (calf pain on dorsiflexion).

What is the patient's diagnosis?
What is the risk factors for the diagnosis?
What are the pathophysiological changes associated with this disorder?
What changes might you expect in ventilation/perfusion?
Would you expect to see changes in the spirometry readings (tidal volume and FEV1)?

1. The person is diagnosed with large right sided spontaneous pneumothorax with posssible background of emphysematous disease.

2. The main risk factors are

AGE;Pulmonary emphysema usually occurs at the age of 40-60.Here the person is having the age of 57.

SMOKING;The disease mainly develops in smokers.

occupational or chemical exposure

expoure to second hand smoke also cause the disease.

3.PATHOLOGICAL CHANGES;Smokers have increased no.of neutrophills and macrophages in their alveoli and the smoking stimulates release of elastase and enhances elastase activity in macrophages.Smoking inhibits alpha antitrypsin.Tobacco smoke contains reactive oxygen species with inactivation of anti protease.alpha anti trypsin deficiency leads to tissue damage and emphysema.

4.Increased V/Q ratio:

As a result of emphysema V/Q increase because of the ventilation (V) stays the sameand perfusion (Q) GOES DOWN.Due to damaged alveoli in lungs in the emphysema also cause increase V/Q ratio.

5.Tidal volume decrease because the patient can't inhale and exhale normally. FEV1 (forced expiratory volume) it also low because of the damaged alveolar spaces.

Explanation:

The patient's diagnosis is PULMONARY EMBOLISM.

A condition in which one or more arteries in the lungs get blocked by a blood clot.

Risk factors;

The risk factors for pulmonary embolism are;

Obesity/overweight, pregnancy/puerperium,taking hormonal drugs like oral contraceptives,smoking,certain disease conditions like stroke, chronic heat disease/high blood pressure,having a surgery (post surgery) or broken bone.(injury/fracture).

Pathophysiology;

Following any of the above cause/risk factor,blood clot will be formed in a deep vein in the leg,the clot travels to the lungs get lodged in a similar lung artery, pulmonary vascular occlusion occurs impairing gas exchange and circulation.as the pulmonary artery systolic pressure increases,right ventricular afterload increases leading to right ventricular failure.

Changes in ventilation/perfusion;

Pulmonary embolism causes redistribution of blood in the lungs impairing ventilation/perfusion.there is ventilation/perfusion matching and gas exchange, pulmonary arterial gas pressure is elevated(PAP) by increasing pulmonary vascular resistance (PVR).

Changes in tidal volume and FEV1;

There will be increased in tidal volume and FEV1 (forced expiratory volume) as a result of shortness of breath and associated respiratory distress.

the answer to your question is (pancreas).