Pulmonary

Question 1

Alveolar O2 formula?

Normal A-a gradient?

Answer 1

PAO2 = 713*FiO2 - PaCO2/0.8
On room air (21% O2), this is:
PAO2 = 150 - PaCO2/0.8

Normal A-a gradient is <15 mm Hg.
Increases with aging but should always be <30 mm Hg

Question 2

Light criteria for an exudative effusion

Answer 2

At least one of:

• Pleural fluid protein / serum protein ratio > 0.5
• Pleural fluid LDH / serum LDH ratio > 0.6
• Pleural fluid LDH > 2/3 the upper limit of normal for serum LDH

Question 3

How can the severity of ARDS be graded?

Answer 3

PaO2 / FiO2 (P/F) ratio:
<100: Severe
<101-200: Moderate
<201-300: Mild

Question 4

O2 saturation goal in ARDS

Answer 4

88-95% saturation (PaO2 55-80)

Question 5

Extrapulmonary involvement of sarcoidosis (5)

Answer 5

1. Skin lesions (e.g. erythema nodosum)
2. Uveitis
3. Arthralgias
4. Hypercalcemia
5. Heart disease

Question 6

Hypoxia with a petechial rash and neurological signs after trauma

Answer 6

Fat embolism from long-bone fracture to lungs

Question 7

Mechanism of secondary spontaneous pneumothorax

Answer 7

Rupture of alveolar blebs due to chronic destruction of alveolar sacks

(seen in chronic lung disease like COPD and CF)

Question 8

Sensory complication of aspirin-induced respiratory disease

Answer 8

Anosmia (due to nasal polyps from chronic rhinosinusitis)

Question 9

When is long-term suppelemntal oxygen started in COPD?

Answer 9

SaO2 < 89% (PaO2 55 mm Hg) ORA in patients with cor pulmonale, right heart failure, or hematocrit >55%

SaO2 <88% (PaO2 <59 mm Hg) ORA in anyone else

Question 10

Treatment for all acute COPD exacerbations?

Moderate-to-severe? How is this defined?

Answer 10

1. Oxygen (to SpO2 of 88-92%)
2. Inhaled bronchodilators
3. Systemic glucocorticoids

Moderate-to-severe: add antibiotics

Moderate-to-severe: at least 2 cardinal symptoms (increased dyspnea, increased sputum volume, incerased sputum purulence) or need for NPPV or intubation

Question 11

Cardinal symptoms of COPD exacerbation

Answer 11

1. Increased dyspnea
2. Increased sputum volume
3. Increased sputum purulence

Question 12

Cause of panacinar emphysema in a young person?

Manifestation outside the lung

Answer 12

Alpha-1-antitrypsin (AAT) deficiency

Also leads to liver disease (e.g. hepatitis, cirrhosis, HCC)

Question 13

Rare but specific signs of PE on CXR (3)

Answer 13

Westermark’s sign: area of hyperlucency distal to a visible pulmonary vessel

Hampton’s hump: peripheral wedge of lung opacity due to infarct

Fleischner sign: enlarged pulmonary artery

Question 14

Rare but classic sign of PE on EKG

Answer 14

S1Q3T3:

• Deep S wave in I
• Q wave in III
• Inverted T wave in III

Question 15

Rapidly progressing, necrotizing post-influenza pneumonia in a young person

Answer 15

Staph aureus

Question 16

First-line treatment for community acquired pneumonia

Answer 16

No recent antibiotics or major comorbidities: macrolide (e.g. azithromycin) or doxycycline

With recent antibiotics or comorbidities: add a beta-lactam (e.g. ceftriaxone), or just use a respiratory fluoroquinolone (e.g. levofloxacin or moxifloxacin)

Question 17

Tool for predicting community-acquired pneumonia severity and management:

Answer 17

CURB-65: one point for each of
Confusion
Urea >20
Respirations >30
BP low (systolic <90, diastolic <60)
65 years or older

0: low mortality, outpatient
1-2: Intermediate mortality, likely admission
3 or more: high mortality, urgent admission

Question 18

Treatment options for pneumonia when aspiration suspected

Answer 18

• Amp/sulbactam (IV if inpatient) or amoxicillin/clavulanate (PO if outpatient)
• Clindamycin
• Metronidazole + amoxicillin or penicillin

Question 19

Most common organisms for ventilator-associated pnuemonia

Answer 19

Gram-negative rods (Pseudomonis, E. coli, Klebsiella pneumonia) or gram positive cocci (Strep and Staph aureus)

Question 20

Pneumonia associated with hyponatremia

Answer 20

Legionella (damage to JG cells that secrete renin)

Question 21

Treatment for Legionella

Answer 21

Fluoroquinolones (levofloxacin) or macrolides (azithromycin)

Question 22

Specific symptoms of Pancoast tumors

Answer 22

1. Referred shoulder pain
2. Horner symptom (sympathetic chain invasion)
3. Brachial plexus invasion leading to arm motor and sensory symptoms
4. Supraclavicular lymph node

Question 23

Paraneoplastic syndrome(s) associated with lung SCC

Answer 23

Hypercalcemia (PTHrp)

Question 24

Paraneoplastic syndrome(s) associated with small cell lung cancer

Answer 24

1. Cushing syndrome (ACTH production)
2. SIADH
3. Lam`bert-Eaton myasthenic syndrome (antibodies against NMJ Ca2+ channels)

Question 25

Lung cancer most associated with necrotizing and cavitation on CT

Answer 25

SCC