CM- Restrictive Lung Diseases

Question 1

Describe the PFT findings for restrictive lung disease.

Answer 1

FEV1/FVC ratio is preserved because airway resistance is not markedly elevated and expiratory flow rates are maintained.
TLC is reduced- less air is held by the lungs so the FEV1 and FVC are both decreased (but proportionately

Question 2

What happens to the following in restrictive lung disease:

1. vital capacity
2. FEV1
3. FEV1/FVC
4. FEF 25%-75%
5. TLC

Answer 2

1. decreased
2. decreased
3. normal (>80%)
4. normal
5. reduced

Question 3

What happens to the following in obstructive lung disease?

1. FVC
2. FEV1
3. FEV1/FVC
4. FEF 25%-75%
5. TLC

Answer 3

1. decreased
2. GREATLY decreased
3. decreased (<80%)
4. decreased
5. increased

Question 4

In order to confirm lung volume reduction (for restrictive disorders), what tests must be performed?

Answer 4

He dilution technique or

Plethysmography

Question 5

What are the 5 major causes of restriction?

Answer 5

1. Pleural disease (effusion, mesothelioma, fibrosis)
2. Alveolar (hemorrhage, pulmonary edema, pneumonia, eosonphilic pneumonia, alveolar proteinosis)
3. Interstitial (IPF, sarcoidosis, hypersensitivity pneumonitis)
4. Neuromuscular (ALS, myasthenia, botulism)
5. Thoracic cage (obesity, kyphoscoliosis, pregnancy, ascites)

Question 6

What are the 5 major types of ILD?

Answer 6

1. idiopathic interstitial pneumonia
2. systemic disorders
3. occupational/environmental
4. connective tissue diseases
5. drug-induced lung disease

Question 7

What are the 2 major histological classifications for ILD?

Answer 7

1. granulomatous reaction - sarcoidosis, hypersensitivity pneumonitis, berylliosis (environmental/occupational, systemic)
2. inflammatory/fibrotic changes

Question 8

What are the 2 most common ILD?

Answer 8

1. Sarcoidosis- systemic

2. Interstitial Pulmonary Fibrosis (IPF)

Question 9

Describe normal lung interstitium.

what is it composed of, thin/thick, cellular/acellular, etc

Answer 9

Thin, relatively acellular space made of:

1. collagen (2:1 Type I:Type III)
2. elastin
3. proteogylcans

Question 10

How does ILD change the composition of normal lung interstitium?
What are the main physiological results?

Answer 10

1. infiltration of inflammatory cells
2. deposition of excess collagen

This thickens the interstitium leading to:

1. decreased compliance–> increased work of breathing, reduced lung volume
2. Gas exchange is impaired due to loss of alveolar-capillary units–> VQ mismatch, hypoxemia

Question 11

What is usually the primary complaint that patients with ILD present with?

Answer 11

Dyspnea on exertion WITHOUT:

1. sputum
2. wheezing
3. orthopnea
4. paroxsymal attacks

Question 12

When a patient presents with:

• dyspnea on exertion
• no sputum, wheezing, othopnea, paroxysmal attacks
• fever

What are the diagnoses we want to consider?

Answer 12

Infectious disease or sarcoidosis

Question 13

A patient presents with dyspnea on exertion, crackles, clubbing and cyanosis.
What is a likely diagnosis?

Answer 13

ILD

Question 14

A patient presents with dyspnea, tachycardia, chest pain, leg swelling, and syncope. What is the most likely cause?

Answer 14

PE

Question 15

A patient presents with dyspnea, S3 gallop, bibasilar inspiratory crackles, paroxysmal nocturnal dyspnea, orthopnea. What is the most likely cause?

Answer 15

CHF

Question 16

A patient presents with skeletal muscle weakness and dyspnea. What is the most likely cause?

Answer 16

Neuromuscular disorder (ALS, myasthenia, botulism)

Question 17

A patient presents with dyspnea, pale conjunctiva, and tachycardia. What is the most likely cause?

Answer 17

Anemia

Question 18

What are the 3 most prominent findings associated with ILD on physical exam?

Answer 18

1. Crackles- late inspiratory, by sudden explosive opening of previously collapses airways
2. Digital clubbing- esp. with IPF and caused by connective tissue proliferation in the distal phalanx
3. Cyanosis- rapid shallow breathing, very obvious during exercise with RR >30bpm

Question 19

What are lab findings suggestive of IPF and connective tissue disorders?

Answer 19

positive serological tests for ANA or rheumatoid factor

Question 20

What does ABG data show for patients with ILD?

Answer 20

1. pCO2 is normal
2. paO2 is decreased
3. A-a gradient is increased

Question 21

If you suspect ILD, what is the first test you should perform?

Answer 21

Measure PaO2 during exercise.

Exercise hypoxia is a more sensitive test than spirometry early in the course of the disease

Question 22

DLCO measures the gas exchange capacity of the lung. Diseases which decrease the number of __________ or ____________ will lower the DLCO.

Answer 22

1. functional alveoli

2. pulmonary capillaries

Question 23

Why don’t diseases like bronchitis and asthma change the DLCO?

Answer 23

They only affect conducting airways. To lower the DLCO, there needs to be reduced number of alveoli or reduced pulmonary capillaries

Question 24

What are the 6 diseases that affect DLCO?

Answer 24

1. ILD
2. emphysema
3. pulmonary emboli
4. pulmonary hypertension
5. lung resection
6. anemia

Question 25

What are the typical ILD CXR findings? | Do they correlate with the severity of the disease?

Answer 25

1. reduced lung volume 2. diffuse reticulo-nodular markings No- they correlate poorly with symptoms, physiologic abnormalities, and histology

Question 26

You are looking at a chest X-ray and see hilar lymph node enlargement. What is the likely cause?

Answer 26

Sarcoidosis

Question 27

You are looking at a chest X-ray and see small miliary nodules. What is your suspision?

Answer 27

TB

Question 28

You are looking at a CXR and see upper lobe predominance. What is the suspicion?

Answer 28

silicosis

Question 29

You are looking at a CXR and see pleural plaques and calcifications. What is the most possible disease?

Answer 29

Asbestosis

Question 30

What is seen in early ILD on HRCT (high resolution CT)? What does this suggest? Is it reversible?

Answer 30

Ground glass appearance- suggest alveolitis which can respond to inflammatory drug therapy and is reversible

Question 31

What is seen in late ILD on HRCT? What does this suggest? Is it reversible?

Answer 31

You see harsh, coarse, linear white markings and "honeycombing" suggestive of fibrosis. This is irreversible.

Question 32

What drugs would make you consider a drug-induced ILD?

Answer 32

Chemo drugs- bleomycin, busulfan, cyclophosphamide, methtrexate, nitroureas Cardiac drugs- amiodarone, procainamide, hydralazine Antibiotics- nitrofurantoin, isonaizid Illicit- heroin, cocaine

Question 33

How would you be able to diagnose ILD associated with connective tissue disorders? What are some of the disorders?

Answer 33

ILD usually occurs in the setting of long-standing disease so it is generally not the initial presentation. It may also present with pleural involvement (serositis, effusion) 1. SLE 2. RA 3. CREST 4. Sjogrens 5. dermatomyositis/polymyositis

Question 34

A 20-40 year old African American presents to you with non-productive cough, dyspnea, and occassional fever. You do histology and see non-caseating granulomas in multiple organs (skin, lymph nodes, eyes, CNS, bone). CXR shows hilar lymph node enlargement. What are you suspicious of?

Answer 34

Sarcoidosis

Question 35

How are the non-caseating granulomas associated with sarcoidosis formed?

Answer 35

TH1 cytokines (IL12, TNF, IL2) are secreted by alveolar macrophages and T cells

Question 36

How is sarcoidosis diagnosed?

Answer 36

1. compatible clinical picture 2. CXR with enlarged hilar lymph nodes 3. non-caseating granulomas on biopsy

Question 37

What would blood tests of someone with sarcoidosis show?

Answer 37

1. polyclonal hypergammaglobulinemia 2. anergy to specific antigens 3. hypercalcemia

Question 38

What is the difference between hypersensitivity pneumonitis and pneumoconiosis?

Answer 38

Hypersensitivity pneumonitis - organic materials from fungi, bacteria, animals, plants. GRANULOMAS Pneumoconiosis- mineral dusts, NO GRANULOMAS

Question 39

What are the diff diagnoses for hypersensitivity pneumonitis?

Answer 39

pneumonia (acutely) | ILD (chronically)

Question 40

What would you see on histology of the lung for hypersensitivity pneumonitis? How can it be differentiated from sarcoidosis?

Answer 40

You would see granulomas but they will ONLY be in the lung vs. multiple systems

Question 41

What are the 4 most common causes of pneumoconioses?

Answer 41

1. Asbestos 2. Beryllium 3. Talc 4. silica

Question 42

A 55 year old man that worked as a builder comes to you with dyspnea. You take xrays and note pleural plaques. What is your suspicion? What other features are you going to see in his lungs?

Answer 42

Asbestosis- the fibers penetrate the visceral pleura and cause effusion, pleural thickening, and mesothelioma in addition to pulm. fibrosis

Question 43

Which pneumoconiosis mimics sarcoidosis?

Answer 43

Berylliosis

Question 44

What is the presentation of someone with idiopathic pulmonary fibrosis (clinical symptoms, physiology, histology)?

Answer 44

Chronic progressive onset of dyspnea and cough, restrictive lung physiology, and histopathologic pattern of UIP (usual interstitial pneumonia)

Question 45

Why is it important to distinguish IPF from the other ILDs?

Answer 45

IPF is more lethal (50% die in 3 years) | Other ILDs can be treated with corticosteroids and immunosuppressants to improve prognosis.

Question 46

It was previously believed that IPF was the common final pathway of the other ILDs. What is the current theory?

Answer 46

IPF is not characterized by inflammation, but rather fibroproliferation due to abnormal lung tissue healing

Question 47

How is the diagnosis of IPF made?

Answer 47

chronic, progressive fibrosing interstitial pneumonia with the other causes of ILD ruled out. Mostly in people older than 50 (usually white, male smokers)

Question 48

Describe the presentation of someone with familial IPF. What is the incidence? How is it inherited?

Answer 48

It is 0.5% to 3.5% of all cases of IPF characterized by early onset of disease. It is autosomal dominant with incomplete penetrance. It presents the same as non-familial IPF but at an earlier age.

Question 49

What genes are thought to be mutated to cause familial IPF? | Describe the process.

Answer 49

1. heterozygous mutations in telomerase 2. Surfactant protein A2 and C SPA2 and SPC mutations lead to lung injury. Repair occurs with mutated telomerase which leads to excessive fibrosis.

Question 50

What is the treatment for IPF?

Answer 50

Lung transplant in individuals 70 or younger