Section 5: Respiratory Disorders

The diagnosis of “obstructive” pattern in pulmonary function testing requires one of the following:

A. Positive bronchodilator response

B. Increased FEV₁/FVC ratio

C. Decreased FEV₁/FVC ratio

D. Increased total lung capacity

E. Decreased residual volume

The answer is C. Obstruction is defined as a decreased FEV₁/FVC ratio in spirometry. Both values are affected but the FEV₁ is decreased to a greater extend that makes the ratio low.

A positive bronchodilator response is defined as:

A. Increase in FEV₁ >500 mL

B. Increase in FEV₁>200 mL

C. Increase in FEV₁>12%

D. Increase in FEV₁ >200 mL and 12%

The answer is D. A positive bronchodilator response is defined by an increase of 12% and 200 mL after the administration of a B -agonist. Both criteria need to be met.

A patient can be described as having “air trapping” on their pulmonary function testing when which of the following findings is present?

A. Increased total lung capacity

B. Increased residual volume

C. Increased DLCO

D. Increased FEV₁/FVC ratio

The answer is B. Air trapping is defined as the inability to fully exhale and diagnosed when the Residual volume is increased above 120% normal.

The following are causes of restrictive lung pattern in pulmonary function tests except:

A. Pleural effusion

B. Pulmonary fibrosis

C. Asthma

D. Neuromuscular disease causing weakness of the respiratory muscles

The answer is C. Asthma is characterized by and obstructive pattern on spirometry, all the other pathologies have a restrictive pattern.

A 64-year-old woman presents to his primary care physician with dyspnea on exertion and chronic cough. She is and active smoker and has been smoking one pack of cigarettes a day for 40 years. Her physician suspects the diagnosis of COPD. What set of pulmonary function test confirms the diagnosis?

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