PATH - Obstructive Lung Diseases

Question 1

Obstructive lung diseases

Answer 1

Obstruction of air flow resulting in air trapping in lungs

*DEC FEV1/FVC ratio (

Question 2

Chronic bronchitis

“blue bloater”

Answer 2

Hyperplasia of mucus-secreting glands in
bronchi–>*Reid index (thickness of mucosal
gland layer to thickness of wall between epithelium and cartilage) > 50%.

Productive cough for > 3 (not necessarily consecutive) months per year for > 2
consecutive years

Findings: wheezing, crackles, cyanosis, late-onset
dyspnea, CO2 retention (hypercapnia), 2° polycythemia

Chronic complications: pulmonary hypertension, cor pulmonale.

Question 3

Emphysema (“pink puffer”)

Answer 3

Enlargement of air spaces,  DEC recoil, INC compliance,  DEC diffusing capacity for CO resulting from *destruction of alveolar walls

Exhalation through *pursed lips to INC airway pressure and prevent airway collapse during respiration.

*Barrel-shaped chest. X-ray shows INC AP diameter, flattened diaphragm, INC lung field translucency.

Two types:
ƒ-Centriacinar—associated with smoking. Frequently in *upper lobes.
ƒ-Panacinar—associated with *α1-antitrypsin deficiency. Frequently in *lower lobes.

Question 4

Asthma

Answer 4

Bronchial hyperresponsiveness causes reversible bronchoconstriction

Findings: cough, wheezing, tachypnea, dyspnea, hypoxemia, DEC inspiratory/expiratory
ratio, pulsus paradoxus, mucus plugging

Smooth muscle hypertrophy,
*Curschmann spirals (shed epithelium forms whorled mucus plugs), and *Charcot-
Leyden crystals (eosinophilic, hexagonal, double-pointed, needle-like crystals formed
from breakdown of eosinophils in sputum).

Peribronchial cuffing on CXR

Clinical diagnosis can be supported by spirometry and methacholine challenge

Question 5

Bronchiectasis

Answer 5

Chronic necrotizing infection of bronchi–> permanently *dilated airways, purulent sputum, recurrent infections, hemoptysis, digital clubbing