05-17-2008, 09:57 AM
A 45-year-old female is seen in the clinic for evaluation of a chronic cough. She reports a cough that began in her early twenties that is occasionally productive of yellow or green thick sputum. She has been treated with innumerable courses of antibiotics, all with brief improvements in the symptoms. The patient has been told that she has asthma, and her only medications are fluticasone and albuterol metered-dose inhalers (MDIs). Physical examination is notable for normal vital signs and an oxygen saturation of 92% on room air. The patient's lungs have dullness in the upper lobes bilaterally and diffuse expiratory wheezing. She has mild digital clubbing. The remainder of the physical examination is normal. Pulmonary function testing shows airflow obstruction. Review of the sputum culture data shows that she has had multiple positive cultures for Pseudomonas aeruginosa and Staphylococcus aureus. Posteroanterior (PA) and lateral chest radiography shows bilateral upper lobe infiltrates. Which of the following tests is the most important first step in diagnosing the underlying disease?
A. Chest computed tomogram (CT)
B. Bronchoscopy with transbronchial biopsy
C. Sweat chloride testing
D. Blood polymerase chain reaction (PCR) for F508 mutation
E. Sputum cytology
A. Chest computed tomogram (CT)
B. Bronchoscopy with transbronchial biopsy
C. Sweat chloride testing
D. Blood polymerase chain reaction (PCR) for F508 mutation
E. Sputum cytology
