A 54-year-old man comes to the office due to shortness of breath that has slowly worsened over the last 6 months. He also has a persistent, nonproductive cough. The patient does not use alcohol, tobacco, or illicit drugs. Temperature is 36.8 C (98 F), blood pressure is 132/78 mm Hg, pulse is 74/min, and respirations are 16/min. Physical examination reveals fine crackles bilaterally on pulmonary auscultation and drumstick-shaped fingers. Chest x-ray reveals diffuse reticular opacities. Pulmonary function testing shows decreased FVC, increased FEV1/FVC ratio, and expiratory flow rates that are higher than normal when corrected for lung volume. This patient's supernormal expiratory flow rates are best explained by an increase in which of the following parameters?

Question

A 54-year-old man comes to the office due to shortness of breath that has slowly worsened over the last 6 months.  He also has a persistent, nonproductive cough.  The patient does not use alcohol, tobacco, or illicit drugs.  Temperature is 36.8 C (98 F), blood pressure is 132/78 mm Hg, pulse is 74/min, and respirations are 16/min.  Physical examination reveals fine crackles bilaterally on pulmonary auscultation and drumstick-shaped fingers.  Chest x-ray reveals diffuse reticular opacities.  Pulmonary function testing shows decreased FVC, increased FEV1/FVC ratio, and expiratory flow rates that are higher than normal when corrected for lung volume.  This patient's supernormal expiratory flow rates are best explained by an increase in which of the following parameters?

Quizplus · Accepted Answer

Eductional Objective: Interstitial lung disease is associated with decreased lung volumes and increased lung elastic recoil caused by fibrotic interstitial tissue.  The increased elastic recoil results in increased radial traction (outward pulling) on the airways, leading to increased expiratory flow rates when corrected for the low lung volume.

A 54-Year-Old Man Comes to the Office Due to Shortness