Respiratory

Question 1

What is paradoxical vocal cord motion (PVFM)? How does it present?

Answer 1

Inappropriate motion of the true vocal folds - episodic unintentional adduction of the vocal folds on inspiration.

Wheezing, stridor, and apparent upper airway obstruction.

Question 2

What is the gold standard for diagnosis of PVFM?

Answer 2

Laryngoscopy

Question 3

What does the flow-volume loop loop like in PVFM?

Answer 3

Flattened inspiratory loop consistent with extrathoracic airway obstruction (this can be induced with spirometry with a metacholine challenge)

Question 4

What are some features more suggestive of PVFM than asthma?

Answer 4

Subjectively more difficulty on inspiration than expiration
Minimal response to aggressive asthma treatment
A flattened inspiratory flow-volume loop
Normal expiratory spirometry, lung volumes, and arterial blood gas measurements

Question 5

In the normal lung, the greatest contribution to increased airway resistance is _________ ?

Answer 5

The medium-sized bronchi (in between the 4th and 8th bifurcation)

Question 6

How can airways resistance be measured?

Answer 6

Body plethysmography

Question 7

What is the greatest contraindication to the low tidal volume, low airway pressure ventilation strategy (permissive hypercapnia) in ARDS?

Answer 7

Head injury/raised ICP (need to also use caution with underlying heart disease

Question 8

Which of the following is the only one to have proven mortality benefit in ARDS: NO, prostacyclins or prone positioning?

Answer 8

Prone positioning - contraindicated in pregnancy, burns, spine instability, abdominal surgery, unstable fractures

Question 9

What are the contraindications to a methacholine challege?

Answer 9

Stroke/MI in previous 3 months, inability to perform PFTs, recent eye surgery, known aortic aneurysm, uncontrolled HTN, FEV1 <60

Question 10

What defines a positive methacholine challenge test? What is the pc20?

Answer 10

Fall in FEV1 of >20% with a delivered concentration of methacholine of <16mg/mL (400mcg). Pc20 is the concentration at which there is a 20% fall in FEV1

Question 11

What would a positive sputum silver stain and bilateral alveolar infiltrates likely represent?

Answer 11

PCP

Question 12

What is the treatment for PCP?

Answer 12

Co-trimoxazole (and adjunctive glucocorticoids if paO2 <70mmgHg)