COPD and Restrictive Lung Disease Flashcards
What can cause both inspiratory and expiratory obstructive lung disease?
Fixed intra or extra thoracic obstruction
What can cause inspiratory obstructive lung disease?
Snoring
Foreign body
What can cause an expiratory obstructive lung disease?
Asthma COPD Bronchiectasis Bronchiolitis Broncheomalacia
What is the mechanism of obstruction in asthma?
Bronchospasm
Inflammation
Mucus
What is the mechanism of obstruction in chronic bronchitis?
Bronchospasm
Inflammation
Mucus
What is the mechanism of obstruction in emphysema?
Loss of lung elastic recoil
What are the main symptoms of obstructive lung disease?
Dyspnea
Cough - in asthma and chronic bronchitis, not emphysema
Wheezing
What are some important questions to ask a patient with suspected obstructive lung disease?
Dyspnea - when did it start and get worse
Cough - productive?
Smoking history
History of allergy
History of wheezing - not in pure emphysema
What are physical findings to focus on when evaluating patients with obstructive lung disease?
RR
Cyanosis - 5 grams unsaturated hemoglobin/100 cc of blood, more hemoglobin shows this more readily, rarely in asthma or emphysema
Decreased breath sounds (asthma indicate attack, common in emphysema), wheezing or rhonchi (rare inspiratory in stable asthma or COPD, expiratory more common, no rhonchi in emphysema)
Rales should not be heard - dry suggest restriction like fibrosis
What is the alveolar air equation?
PAO2 = 150 - (PaCO2/.8)
What is the hallmark of obstructive lung disease?
FEV1/FVC less than 70% AND FEV1 less than 80%
What is the Ddx of a fixed obstruction?
Laryngeal carcinoma
Thyromegaly
Vocal cord asthma
What is the Ddx of a variable extra thoracic obstruction?
Obstructive sleep Alena
Tracheomalacia
Inhibits inspiratory limb of flow volume loop
What is the Ddx of a variable intrathoracic obstruction?
Asthma
COPD
Bronchiectasis
Affects expiratory limb on flow volume loop
What DLCO means patient will develop arterial hypoxemia with exercise?
<45%
When is an ABG ordered?
When FEV1 less than or equal to 30-40% predicted
Normal pCO2 of 41 is bad sign in someone with asthma - developing respiratory acidosis (should be lower)
What ABGs are present in COPD?
Emphysema usually has pCO2 < 45 and moderate hypoxemia (60-70) on room air at rest
Chronic bronchitis have pCO2 > 45 and pH only marginally low due to compensatory metabolic alkalosis, pO2 often <7.31) indicates acute worsening of COPD with worsening CO2 retention
What are interstitial lung diseases?
Affect both alveolar and interstitial compartments
Lead to restriction
What are the five categories of ILDs?
Idiopathic interstitial pneumonias Connective tissue diseases Drug induced diseases Other systemic disorders Occupational and environmental exposures Last two are granulomatous
What are signs and symptoms of ILDs?
Dyspnea
Tachypnea more prominent with exercise
Normal PaCO2, decreased PaO2, increased A-a gradient
Exercise induced hypoxemia sensitive for early disease
Crackles, clubbing, cyanosis
Interstitial lung disease
Wheezes, prolonged expiratory phase, distant breath sounds
Obstructive lung disease, including asthma
Tachycardia, chest pain, leg swelling, syncope
Pulmonary emboli
S3 gallop, bibasilar inspiratory crackles, PND, orthopnea
Cardiac disease
Pale conjunctiva, tachycardia
Anemia
What are HRCT findings and what do they indicate?
Ground glass appearance - alveolitis which can be reversible
Dense lines and honey combing - fibrosis, irreversible
What are common causes of drug induced ILD?
Chemo - bleomycin, busulfan, cyclophosphamide, methotrexate, nitrosoureas
Cardiac - procainemide, amiodarone, hydralazine
Antibiotics - isoniazid, nitrofurantoin*
Illicit drugs - heroine, cocaine
Where are crackles less common?
Sarcoidosis
Where is clubbing especially predominant?
IPF
Asbestosis
What is loffgren’s syndrome?
Erythema nodosum (painful nodular panniculitis and vasculitis), bilateral hilar adenopathy and arthralgias Associated with sarcoidosis
What is Heerfordts syndrome?
Facial nerve palsy, parotidis, uveitis
Associated with sarcoidosis
What is the natural history of sarcoidosis?
Therapy withheld until evidence of vital organ dysfunction - then corticosteroids, with or without immunosuppressants
1/3 spontaneously remit in 3 yrs, 1/3 progress over 5-10 yrs, 1/3 remain stable
What mimics sarcoidosis?
Berylliosis - a pneumoconiosis
How is hypersensitivity pneumonitis a mimic?
Acute resemble pneumonia
Subacute resemble tb
Chronic resemble IPF
What are the shared clinical features of pneumoconioses?
Inhalation of inorganic material
Linear dose response
Long latency
Symptoms and disease limited to respiratory system
No known treatment except removal from exposure
Very slow progression
What are connective tissue diseases associated with ILD?
SLE RA Systemic sclerosis / CREST syndrome Sjogrens Dermatomyositis / poly myosotis
What are hallmarks of connective tissue diseases and ILD?
Underlying disease usually present before lung involvement
Multisystem involvement
Younger age of onset
What is idiopathic pulmonary fibrosis?
Chronic progressive dyspnea and cough, restrictive lung physiology, and UIP histologic pattern
Characterized not by inflammation, but by chronic fibroproliferation due to abnormal lung tissue wound healing
Rare in children, typically over 50, common in men and smokers
Exclude other ILD causes
Peripheral distribution
Reticulations in lower lobes, honeycombing and traction bronchiectasis
Why is it important to distinguish IPF from other ILDs?
IPF is the most lethal and doesn’t respond to corticosteroids and immunosuppressants
Only possible treatment is transplant but this is rare
What is the molecular basis for the familial form of IPF?
AS pattern with incomplete penetrate
Same presentation as clinical IPF but earlier age of onset
Heterozygous mutations in genes encoding telomerase
Mutations in gene encoding surfactant proteins A2 and C
