Restrictive Lung Disease

Question 1

Physiologic abnormalities in restrictive lung disease

Answer 1

TLC AND FRC < 80

Decreased compliance (stiffer lungs OR restricted motion of the chest wall)

P-V curve is flatter and shifted downward (reflecting lower compliance & decreased lung volumes)

FEV1/FVC often normal or slightly elevated

Question 2

3 mechanisms that lead to restrictive physiology

Answer 2

1. Increased thickness of lung interstitium (ILD)
2. Increased lung water (interstitial/alveolar edema)
3. Increased alveolar surface tension (RDSI, ARDS, pulmonary edema)

Question 3

Differentiation of restrictive disease vs. physiology

Answer 3

P-V curve slope is reduced in restrictive lung disease but preserved in restrictive physiology (with lower TLC)

DLCO/VA is reduced in restrictive disease but preserved in restrictive physiology

Question 4

PFT pattern of mixed lung disease

Answer 4

Reduced lung volumes (decreased TLC, FRC)

Reduced air flow (decreased FEV1/FVC)

Question 5

Diagnostic approach to interstitial lung disease

Answer 5

Clinical

Radiographic (high resolution CT)

Pathologic (surgical lung biopsy)

Question 6

Known causes of ILD

Answer 6

Autoimmune (RA, lupus, scleroderma)
Exposure to inorganic dusts (silica, asbestos)
Exposure to organic molecules (birds, mold)
Drug effects (chemo, radiation)
Familial

Question 7

Sarcoidosis & Chronic Beryllium Disease - Pathology

Answer 7

Systemic, granulomatous inflammation disorders of unknown (Sarcoid) or known (CBD) etiology

Characterized by the presence of well-formed, non-necrotizing granulomas surrounded by collagen deposition; often follow lymphatic distribution

Question 8

Sarcoidosis - Treatment

Answer 8

Usually none

Sometimes corticosteroids or methotrexate to treat/prevent progressive organ involvement

Question 9

Idiopathic pulmonary fibrosis (IPF) - Definition

Answer 9

Idiopathic, scarring lung disease with a pattern of lung injury consistent with usual interstitial pneumonia (UIP)

Question 10

Usual Interstitial Pneumonia (UIP)

Answer 10

Most common pattern if ILD

Patchy, heterogenous fibrosis of the septa by collagen; usually worse in lower lobes

Fibroblastic foci - compact collections of fibroblasts within the alveolar septae, bulging out into the airspaces

Honeycomb cystic change - formation of mucus-filled cysts surrounded by thick, fibrotic walls

Question 11

IPF - Radiographic findings

Answer 11

Peripheral and basilar predominant reticulation and bronchiectasis

Question 12

Idiopathic Nonspecific Interstitial Pneumonia (NSIP)

Answer 12

Uniform, homogenous inflammation (cellular type) or fibrosis (fibrotic type); cellular type is steroid-responsive

Lack of fibroblastic foci and honeycombing

Question 13

Clinical characteristics of IPF vs. NSIP

Answer 13

NSIP is more likely to affect younger females, is more responsive to anti-inflammatory treatment, and has a better prognosis

Question 14

Cryptogenic organizing pneumonia

Answer 14

Noninfectious pneumonia - may be idiopathic, secondary to drugs HP, or aspiration

Path shows organizing pneumonia with plugs of granulation tissue

Steroid responsive

Question 15

Pulmonary manifestatiosn of ALS

Answer 15

Dysphagia - risk of aspiration pneumonia
Restrictive physiology due to respiratory muscle weakness
Hypoventilation - elevated PCO2

Question 16

Pulmonary manifestations of Rheumatoid Arthritis

Answer 16

Rheumatoid effusion - exudative with increased protein and > 3,000 WBCs

Pleuritis

Lung nodules

Pulmonary hypertension (2/2 vasculitis)

Question 17

Goodpasture Syndrome

Answer 17

Caused by auto-antibodies directed against pulmonary and glomerular basement membrane proteins

Associated with diffuse alveolar hemorrhage, resulting in restrictive disease (due to alveolar destruction)

Question 18

Pulmonary manifestations of Sickle Cell Disease

Answer 18

Acute Chest Syndrome
Infection (2/2 spleen auto-infarct)
Bone marrow emboli (2/2 bone marrow auto-infarct)
Lung infarction (2/2 in-situ thrombosis)
Pulmonary edema
Pulmonary HTN

Question 19

Acute pneumonia - Pathology

Answer 19

Characterized by an accumulation of neutrophils, macrophages, and fibrin within air spaces

Question 20

Eosinophilic pneumonia - Pathology

Answer 20

Characterized by an accumulation of eosinophils, macrophages, and fibrin within air spaces

Question 21

Organizing pneumonia (AKA BOOP, COP) - pathology

Answer 21

Fibroblast plugs filling airspaces - usually in a “patchy” pattern; some fibrin deposition within air spaces

Reversible, steroid responsive

Question 22

Respiratory bronchiolitis

Answer 22

Characterized by the presence of brown pigmented macrophages inside airspaces surrounding the respiratory bronchiole; air spaces farther away from the airway are usually spared

Smokig-related disease; macrophages are trying to clear the cigarette smoke particles but end up leading to air space destruction

Question 23

Diffuse alveolar damage (DAD) - pathology

Answer 23

Presence of fibrin ribbons (“hyaline membranes”) caked over the alveolar membranes; alveolar space are sealed off from gas exchange

This pattern is characteristic of ARDS and Respiratory Distress Syndrome of the Infant

Question 24

Diffuse alveolar hemorrhage - Pathology

Answer 24

Presence of blood and iron-containing macrophages within the air spaces; may be associated with capillaritis (neutrophils attacking the capillaries of the alveolar septa)

Question 25

Hypersensitivity Pneumonia (HP) - Pathology

Answer 25

Response to foreign antigens (birds, mold) characterized by: Airway-centered chronic inflammation (lymphocytes and activated macrophages) Non-necrotizing granulomas Organizing pneumonia

Question 26

Causes of acute consolidation on CXR

Answer 26

HEAP Hemorrhage Edema Alveolar Protein Pneumonia

Question 27

Hypersensitivity Pneumonitis

Answer 27

Presents acutely with flu-like respiratory illness occurring after acute, high dose antigen exposure

Question 28

Chronic Beryllium Disease (CBD)

Answer 28

A chronic, granulomatous lung disease pathologically indistinguishable from sarcoid Treatment: Inhaled or oral steroids

Question 29

Coal Workers' Pneumoconiosis (Black Lung) - Diagnosis

Answer 29

Imaging shows small, rounded, nodular opacities present in the upper lobes

Question 30

Silicosis

Answer 30

Upper lobe predominant nodular interstitial lung disease; may progress to involve architectural distortion and volume loss (complicated silicosis)

Question 31

Asbestosis

Answer 31

Bilateral fibrosis affecting the lower lung zones preferentially

Question 32

Non-malignant asbestos-related lung diseases

Answer 32

Asbestos pleural effusion Pleural thickening/calcification Rounded atelectasis Asbestosis

Question 33

Malignant asbestos-related lung diseases (2)

Answer 33

Lung cancer - all histologic types | Mesothelioma

Question 34

5 ILDs associated with environmental exposure

Answer 34

``` Asbestos-related lung disease Silicosis Coal Miner's Pneumoconiosis (Black Lung) Chronic Beryllium Disease Hypersensitivity Pneumonitis ```

Question 35

Risk groups for asbestos exposure

Answer 35

Construction workers Boilermakers Shipyard and dock workers Automechanics who do brake work

Question 36

Risk groups for silicosis

Answer 36

Workers who blast, cut, or grind hard rock Sandblasters Foundry workers Stone-washed jean manufacturers

Question 37

Risk groups for Chronic Beryllium Disease

Answer 37

Beryllium is a lightweight metal used in aerospace engineering and high tech electronics Aerospace workers, airplane mechanics, air traffic controllers, etc. are all at higher risk

Question 38

Triggers of Hypersensitivity Pneumonitis

Answer 38

``` Animal proteins (birds) Microbial aerosols (fungi, hot tubs and indoor pools, humidifiers) ```