Review Question - QID 100887

The patient has chronic bronchitis and he will have pulmonary function tests (PFTs) similar to those seen in other obstructive lung diseases, such as emphysema and asthma exacerbations: decreased FEV1, FVC, and FEV1/FVC and in more severe disease, increased TLC and RV .

TLC refers to total lung capacity. RV is the residual volume (what is left in the lung after a complete exhalation). FEV1 is the forced expiratory volume in one second or the volume of air that can be blown out in first second of an FVC maneuver. FVC is the forced vital capacity or the total volume of air that can be blown out after a maximal inspiration. The ratio of FEV1/FVC is useful because its reduction suggests obstructive rather than restrictive lung disease.

Chronic bronchitis is a condition defined by its presentation, which is a chronic sputum-producing cough that has persisted consecutively for 3 months and has been going on for 2 years. It is marked by goblet cell hyperplasia and chronic inflammation. PFTs show an obstructive pattern.

Stephens et al. discuss the importance of spirometry in diagnosing COPD. The authors note that an FEV1/FVC less than 70% and an FEV1 that is lower than 80% (compared to normal values), are indicative of COPD.

Braman discusses how chronic bronchitis, which is mainly caused by smoking, leads to chronic inflammation and heightened mucus production. The author notes that as the inflammation and histologic changes persist, there is increased obstruction to airflow and dyspnea results.

Illustration A shows the hallmarks of obstructive lung diseases: decreased FEV1 and FVC, increased lung volume.

Incorrect Answers:
Answer 1: A patient with unsymptomatic asthma frequently will have normal spirometry and lung volumes.
Answers 2, 4, and 5: These conditions lead to fibrosis formation and restrictive lung physiology. PFT's show demonstrate a restrictive pattern with reduced FVC, TLC and FEV1 and normal FEV1/FVC ratio.