Pathological Cases of the Month

A 6-YEAR-OLD BOY with cystic fibrosis presented to the hospital with low-grade temperature, cough, increased sputum production, and decreased appetite of 2 weeks' duration. Physical examination revealed a body temperature of 38.5°C, a respiration rate of 25 breaths per minute, a cardiac rate of 130 beats per minute, and a blood pressure of 105/60 mm Hg. The child looked pale and weak. Auscultation of the chest revealed decreased breath sounds and bilateral inspiratory and expiratory rales. Chest roentgenography showed a diffuse bilateral interstitial infiltrate, peribronchial thickening, and moderate hyperinflation. Oxygen saturation, while breathing room air, was 90%. Spirometry results showed a forced expiratory volume of 0.70 (59% of predicted), and a forced expiratory volume to forced vital capacity ratio of 80%. His total leukocyte count was lOXlO³mL. Culture of the sputum yielded Pseudomonas aeruginosa and Staphylococcus aureus. The patient was admitted to the hospital for treatment of acute