Chest wall complianceDownloads

An 85-year-old man with hypertension and type 2 diabetes mellitus is brought to the emergency department because of a 2-day history of shortness of breath. He has smoked one pack of cigarettes daily for 30 years. His temperature is 36.9°C (98.4°F), pulse is 100/min, respirations are 30/min, and blood pressure is 138/75 mm Hg. Pulmonary function testing shows decreased tidal volume and normal lung compliance. Which of the following is the most likely underlying etiology of this patient's tachypnea?

A 57-year-old man presents to the clinic for a chronic cough over the past 4 months. The patient reports a productive yellow/green cough that is worse at night. He denies any significant precipitating event prior to his symptoms. He denies fever, chest pain, palpitations, weight changes, or abdominal pain, but endorses some difficulty breathing that waxes and wanes. He denies alcohol usage but endorses a 35 pack-year smoking history. A physical examination demonstrates mild wheezes, bibasilar crackles, and mild clubbing of his fingertips. A pulmonary function test is subsequently ordered, and partial results are shown below: Tidal volume: 500 mL Residual volume: 1700 mL Expiratory reserve volume: 1500 mL Inspiratory reserve volume: 3000 mL What is the functional residual capacity of this patient?