This 64-year-old man was hospitalized because of increasing shortness of breath, cough, increasing sputum production, and fever. The patient had a 75 pack-year history of cigarette smoking. On admission his respiratory rate was 20 breaths per minute and his pulse was 110 bpm. On room air his PaO2 was 46 mm Hg, his PaCO2 was 62 mm Hg, and the pH was 7.26. He was started on 24% O2 and after 6 hours his PaO2 was 52 mm Hg, his PaCO2 was 54 and his pH was 7.30. His hemoglobin was 17.1 g/dL, his PCV was 54%, and his leukocyte count was 15,300 cells/mm³ with 13% bands, 65% PMNs, 15% lymphocytes, 4% monocytes and 3% eosinophils. Chest x-ray showed a narrow heart silhouette, a low, flattened diaphragm, and markedly lucent regions in the upper lung fields suggesting areas of emphysema. An electrocardiogram showed tall P waves and a right axis deviation. The patient was given broad-spectrum antibiotics and was continued on his oral and inhalant bronchodilators and was started on a diuretic. His condition improved but two days after admission Despite appropriate therapy he suffered acute respiratory failure and could not be resuscitated. Pertinent autopsy findings included emphysema with moderate mucous plugging of bronchi. Right ventricular hypertrophy and dilation were also noted.