IPLab:Lab 12:COPD

Clinical Summary

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 he suffered acute respiratory failure and could not be resuscitated.

Autopsy Findings

Pertinent autopsy findings included emphysema with moderate mucous plugging of bronchi. Right ventricular hypertrophy and dilation were also noted.

Images

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  This gross photograph of lung taken at autopsy demonstrates the degree of emphysematous change (arrows). Also note that the rest of the lung is consolidated, indicating a pneumonia.

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  This is a higher-power view of the lung showing the emphysematous change.

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  This low-power photomicrograph of the lung demonstrates the enlarged air spaces indicative of emphysematous change.

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  This higher-power photomicrograph of the lung shows more clearly the enlarged air spaces indicative of emphysematous change.

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  This gross photograph of the heart taken at autopsy demonstrates right ventricular hypertrophy and dilatation (arrows).

Study Questions

• What is COPD and why do cigarette smokers develop it?

Chronic obstructive pulmonary disease is a group of conditions that lead to dyspnea. COPD entails emphysema, chronic bronchitis, bronchiectasis, and asthma. The conditions can occur to varying degrees and there are often complex combinations and severities of each entity. Cigarette smoke and other air pollutants can irritate the lung and lead to increased leukocytes, increased release of elastases, and increased oxidants which inhibit alpha-1 antitrypsin. These and a variety of other factors lead to destruction of the elastic tissue in the lung and result in abnormal lung function and lung damage.

• What caused the right ventricular hypertrophy and dilatation? What is this called?

The lung damage resulted in pulmonary hypertension which resulted in right ventricular hypertrophy. Over a period of time the increased workload will cause the right ventricle to fail and dilate. This process of right ventricular hypertrophy due to pulmonary hypertension is called cor pulmonale.