Flashcards in COPD and Restrictive Lung Disease Deck (40)
What can cause inspiratory obstructive lung disease?
What can cause both inspiratory and expiratory obstructive lung disease?
Fixed intra or extra thoracic obstruction
What can cause an expiratory obstructive lung disease?
What is the mechanism of obstruction in asthma?
What is the mechanism of obstruction in chronic bronchitis?
What is the mechanism of obstruction in emphysema?
Loss of lung elastic recoil
What are the main symptoms of obstructive lung disease?
Cough - in asthma and chronic bronchitis, not emphysema
What are some important questions to ask a patient with suspected obstructive lung disease?
Dyspnea - when did it start and get worse
Cough - productive?
History of allergy
History of wheezing - not in pure emphysema
What are physical findings to focus on when evaluating patients with obstructive lung disease?
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?
Vocal cord asthma
What is the Ddx of a variable extra thoracic obstruction?
Obstructive sleep Alena
Inhibits inspiratory limb of flow volume loop
What is the Ddx of a variable intrathoracic obstruction?
Affects expiratory limb on flow volume loop
What DLCO means patient will develop arterial hypoxemia with exercise?
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?
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
S3 gallop, bibasilar inspiratory crackles, PND, orthopnea
Pale conjunctiva, tachycardia
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?
Where is clubbing especially predominant?