PATH - Restrictive Lung Diseases

Question 1

Restrictive lung diseases

Answer 1

Restricted lung expansion causes DEC lung volumes (FVC and TLC).

*FEV1/FVC ratio ≥ 80% (preserved)

2 Types:
ƒ-Poor breathing mechanics (extrapulmonary, peripheral hypoventilation, normal A-a gradient):
ƒ -Poor muscular effort—polio, myasthenia gravis, Guillain-Barré syndrome
ƒ -Poor structural apparatus—scoliosis, morbid obesity
ƒ
-Interstitial lung diseases (pulmonary DEC diffusing capacity, INC A-a gradient):
-Acute respiratory distress syndrome
-Neonatal respiratory distress syndrome
-Pneumoconioses
-Sarcoidosis
-Idiopathic pulmonary fibrosis
-ƒGoodpasture syndrome
-Granulomatosis with polyangiitis (Wegener)
-Pulmonary Langerhans cell histiocytosis
-ƒ Hypersensitivity pneumonitis
-Drug toxicity (bleomycin, busulfan, amiodarone, methotrexate)

Question 2

Hypersensitivity pneumonitis

Answer 2

Mixed *type III/IV hypersensitivity reaction to environmental antigen
Ž
dyspnea, cough, chest
tightness, headache

Often seen in *farmers and those *exposed to birds

Question 3

Asbestosis

Answer 3

Associated with shipbuilding, roofing, plumbing

Affects *lower lobes

*“Ivory white,” calcified,
supradiaphragmatic and pleural plaques are pathognomonic of asbestosis

Asbestos (ferruginous) bodies are *golden-brown
fusiform rods resembling dumbbells

Risk of bronchogenic carcinoma > risk of mesothelioma
INC risk of pleural effusions

“Asbestos is from the roof (was common in insulation), but affects the base (lower lobes).”

Question 4

Berylliosis

Answer 4

Associated with exposure to beryllium in aerospace and manufacturing industries

Affects *upper lobes

*Granulomatous

Question 5

Coal workers’ pneumoconiosis

Answer 5

Prolonged coal dust exposure–>macrophages
laden with carbon–>inflammation and fibrosis

Affects *upper lobes

AKA black lung disease

*Anthracosis—asymptomatic condition found in many urban dwellers exposed to sooty air.

“Silica and coal are from the base (earth), but affect the roof (upper lobes).”

Question 6

Silicosis

Answer 6

Associated with foundries, sandblasting, mines

Affects *upper lobes.

*“Eggshell” calcification of hilar lymph nodes.

increasing susceptibility to TB.

“Silica and coal are from the base (earth), but affect the roof (upper lobes).”

Question 7

Pulmonary hypertension

Answer 7

Normal mean pulmonary artery pressure = 10–14 mm Hg

pulmonary hypertension ≥ 25 mm Hg at rest

Results in arteriosclerosis, medial hypertrophy, intimal fibrosis of pulmonary arteries

severe respiratory distress–>cyanosis and RVH–>death from decompensated cor pulmonale