Respiratory

Question 1

Compare ABG of CHF exacerbation vs COPD exacerbation?

Answer 1

CHF: respiratory alkylosis with hypoxia (increased pH, decreased pCO2, and decreased pO2)
COPD: Respiratory acidosis with hypoxia (decreased pH, increased pCO2, and decreased pO2)

Question 2

How are exudates and transudates distinguished?

Answer 2

Exudate:
Effusion protein/serum protein ratio > 0.5
Effusion lactate dehydrogenase (LDH)/serum LDH ratio > 0.6
Effusion LDH level > two-thirds the upper limit of the laboratory’s reference range of serum LDH

Transudate would be < 0.5, 0.6, and two-thirds upper limit respectively

Question 3

What vent setting affect PaCO2?

Answer 3

RR and TV

Question 4

What are the early exam findings in a patient with idiopathic pulmonary fibrosis?

Answer 4

Fine bibasilar crackles in patient with progressive dyspnea

Question 5

In ARDS, what is the PaO2/FiO2 ratio (P/F)?

Answer 5

P/F ≤300 mm Hg

Question 6

What is the pH of normal, transudative, and exudative pleural fluid and empyema?

Answer 6

Normal: 7.60
Transudate: 7.4-7.55
Exudate: 7.30-7.45
Empyema: <7.30

Question 7

How is pulmonary hypertension secondary to LV dysfunction managed?

Answer 7

Loop diuretics and ACE-I, often with beta-blocker and spironolactone

Question 8

What is the management of pulmonary hypertension due to hypoxemia from chronic lung disease?

Answer 8

Bronchodilators and/or oxygen

Question 9

What medications are used to treat idiopathic pulmonary hypertension?

Answer 9

Endothelin receptor antagonists (e.g. bosentan), phosphodiesterase-5 inhibitors (e.g. sildenafil), and/or prostanoids (e.g. epoprostenol)

Question 10

What are two major indicators of poor prognosis in patients with a PE?

Answer 10

Low oxygen saturation and atrial fibrillation

Question 11

How is PAO2 calculated?

Answer 11

PAO2 = (FiO2 x [Patm - PH20]) - (PaCO2/0.8)

Simplified to 150 - (PaCO2/0.8) at sea level

Question 12

What is the expected A - a gradient for a patient?

Answer 12

(Patient age)/4 + 4

Question 13

What is the best diagnostic test for bronchiectasis?

Answer 13

High-resolution CT of the chest - will see bronchial dilation, lack of airway tapering, and bronchial wall thickening

Question 14

What is the mechanism of an exudative pleural effusion?

Answer 14

Increased capillary or pleural permeability or disruptions to lymphatic outflow

Question 15

What should you consider in a patient with recurrent pneumonia in the same location of the lung?

Answer 15

Localized airway obstruction (e.g. neoplasm) - get CT

Question 16

What can cause a “Thickened peritracheal stripe and splayed carina bifurcation” on cxr?

Answer 16

Enlarged L atria (eg mitral stenosis) or an subcarinal mass

Question 17

What is the cause of a transudative pleural effusion with low glucose?

Answer 17

RA

Question 18

What are the main causes of ARDS?

Answer 18

Sepsis, gastric aspiration, trauma, low perfusion, pancreatitis

Question 19

What are the criteria for diagnosis of ARDS?

Answer 19

1. ) PaO2/FiO2 < 200 (<300 means acute lung injury)
2. ) Bilateral alveolar infiltrates on CXR
3. ) PCWP is <18 (means pulmonary edema is non cardiogenic)

Question 20

What constitutes a positive bronchodilator response?

Answer 20

At least a 12% increase in FEV1 (or FVC) = asthma

Question 21

What is the best prognostic indicator in COPD?

Answer 21

FEV1

Question 22

If a patient suddenly develops digital clubbing, what does that indicate?

Answer 22

Underlying malignancy - likely pulmonary (get a cxr)

Finding is called hypertrophic osteoarthropathy

Question 23

What are the lung findings in silicosis?

Answer 23

Small nodules in the upper lobes with eggshell calcifications

Question 24

What test should patients with silicosis get annually?

Answer 24

TB test - predisposed to TB

Question 25

What does a popcorn calcification on cxr indicate?

Answer 25

Hamartoma (benign)

Question 26

How do gas exchange, lung compliance, and pulmonary arterial pressure change in ARDS?

Answer 26

Gas exchange is impaired (ventilation-perfusion mismatch), lung compliance decreases due to loss of surfactant and an increase in elastic recoil of the edematous lungs, and pulmonary arterial pressure increases due to hypoxic vasoconstriction

Question 27

Where is the origin of most PEs?

Answer 27

> 90% come from the proximal LE (e.g. iliac, femoral, popliteal) veins