A 17-year-old student has experienced reversible, periodic attacks of chest tightness with coughing, wheezing, and hyperpnea. She states that expiration is more difficult than inspiration. She is most comfortable sitting forward with arms leaning on some support. X-rays revealed mild overinflation of the chest. Results from laboratory and pulmonary function tests are as follows:

Frequency 20 breaths/min
Vital capacity (VC) 2.9 L
FEV1.0 1.4 L
FEV1.0/FVC 56%
Functional residual capacity (FRC) 3.89 L
Total lung capacity (TLC) 6.82 L
PaO2 70 mm Hg
PaCO2 26 mm Hg
Pulse 108 b/min
BP 120/76 mm Hg
Intermittent use of a bronchial smooth muscle dilator (1:1000 epinephrine by nebulizer) for several days caused marked improvement, resulting in the following laboratory and pulmonary function tests:

VC 4.15 L
FEV1.0 3.1 L
FEV1.0/FVC >75%
FRC 3.7 L
TLC 5.96L
PaO2 89 mm Hg
PaCO2 38 mm Hg
Pulse 129 b/min
BP 122/78 mm Hg

Pick 3 Questions to Discuss!

1. What is the disorder of this 17-year-old student?

2. Is this primarily a restrictive or an obstructive disorder? Why?

3. Why is expiration more difficult than inspiration in this person?