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)