A subject with an FEV₁/FVC ratio of 37% performs a 7-minute N₂ washout test. After 7 minutes,the alveolar N₂ concentration is 5.7%.This is consistent with which
Of the following?

Question

A subject with an FEV₁/FVC ratio of 37% performs a 7-minute N₂ washout test. After 7 minutes,the alveolar N₂ concentration is 5.7%.This is consistent with which Of the following?

Quizplus · Accepted Answer

The FEV1/FVC ratio of 37% suggests airflow limitation, which is consistent with chronic bronchitis. The N₂ washout test is used to measure the concentration of nitrogen in exhaled breath, which is affected by the alveolar concentration of N₂. In chronic bronchitis, there is airway obstruction that leads to air trapping in the lungs, resulting in an elevated concentration of nitrogen and prolonged washout time. The alveolar N₂ concentration of 5.7% after 7 minutes is consistent with this diagnosis. Idiopathic pulmonary fibrosis and pneumoconiosis are associated with restrictive lung disease, and a right-to-left shunt would result in decreased N₂ concentration.

A Subject with an FEV1/FVC Ratio of 37% Performs a 7-Minute

A Subject with an FEV₁/FVC Ratio of 37% Performs a 7-Minute