Correct!
3. The spirometry shows fixed upper airway obstruction.
The chest x-ray is normal. The pulmonary arteries are normal sized and there are no masses which could be arteriovenous malformations. The spirometry was interpreted by the computer as showing “moderate severe obstruction”, which although true, is only part of the story. The FEV1 is decreased but the shape of the flow-volume loop is squared indicting fixed obstruction. The squaring is caused by decreased flows during both inspiration and expiration.
Which of the following is the most likely diagnosis? (Click on the correct answer to be directed to the fifth of seven pages)