Respiratory

Question 1

Young patient with asthma is commenced on salmeterol, what is a potential side effect?

Answer 1

Paradoxically, it can cause an acute exacerbation of asthma possibly due to a hypersensitivity reaction.

Question 2

True/False: where possible, asthmatics should have early intubation to improve outcomes.

Answer 2

False.

Avoid intubating asthmatics if possible, high pressures required and IV salbutamol/magnesium/aminophylline often required.

Question 3

What base excess would trigger the need for bicarbonate?

Answer 3

less than -8

Question 4

Restrictive lung disease from respiratory muscle weakness leads to what changes to the following parameters:

1. FEV1
2. FVC
3. TLC
4. RV
5. RV/TLC
6. TCO

Answer 4

1. FEV1 - grossly lowered
2. FVC - grossly lowered
3. TLC - grossly lowered
4. RV - high due to weakness
5. RV/TLC - elevated, due to high RV
6. TCO - not affected

Question 5

OSA is risk factor for which 3 other conditions?

Answer 5

1. CVA
2. HTN
3. Impaired glucose tolerance / Insulin resistance

Question 6

What is decompression sickness?

Answer 6

• When a diver returns to the surface gas tensions in the tissue exceed the ambient pressure.
• This leads to liberation of free gas from the tissues in the form of bubbles.
• Bubbles cause mischief (organ dysfunction by blocking blood vessels, rupturing or compressing tissue, or activating clotting and inflammatory cascades)

Question 7

How is decompression sickness treated?

Answer 7

• Hydration
• O2-Rx (100%)
• Hyperbaric oxygen therapy
• Position the patient to improve forward blood flow

Hydrate - Oxygenate - Position

Question 8

What is nitrogen narcosis?

Answer 8

• Due to raised partial pressure of nitrogen in nervous system tissue, and usually occurs at depths greater than 100 feet
• Features similar to alcohol or benzodiazepine intoxication.

Question 9

T/F: diseases in which the uptake of oxygen is reduced across the alveolar-capillary interface cause parallel decreases in uptake of carbon monoxide as measured by DLCO.

Answer 9

True

Question 10

What is the effect of anti-fibrotics Nintedanib and Pirfenidone on the natural history of idiopathic pulmonary fibrosis (IPF).

Answer 10

Slow further deterioration of lung function but does NOT reverse parenchymal lung damage.

Question 11

What is Omalizumab?

When is it indicated?

Answer 11

• Ab that binds to free IgE and prevent cross-linking and allergic inflammation.
• Treats severe allergic asthma

Question 12

What is Nintedanib?

When is it indicated (2)?

Answer 12

Inhibitor of multiple growth factors:

PDGFR (platelet-derived growth factor)
FGFR (fibroblast growth factor receptor)
VEGFR (vascular endothelial growth factor receptor)

Treatment for:

1. IPF - antifibrotic effect
2. Lung cancer - inhibits angiogenesis

Question 13

What is Pirfenidone?

When is it indicated (1)?

Answer 13

Anti-fibrotic and anti-inflammatory due to inhibition of:

fibroblast proliferation
TGF-beta stimulated collagen production
IL-1
TNF-alpha

Treatment for IPF.

Question 14

What is Montelukast?

When is it indicated (2)?

Answer 14

Leukotriene receptor antagonist (LTRA)

Treatment of:

1. Asthma
2. Seasonal allergies

Question 15

What is Mepolizumab?

When is it indicated (1)?

Answer 15

mAB to IL-5

Treatment of severe eosinophilic asthma

Question 16

Patient has cystic fibrosis and requires a lung transplant. Single or bilateral?

Answer 16

Bilateral - single lung transplant is CONTRAINDICATED in cystic fibrosis.

Question 17

Patient has a pulmonary function test and is noted to have reduced FEV1/FVC, lung volumes (TLV and RV, RV/TLC also reduced), DLCO and KLCO.

What is the diagnosis?

Answer 17

Pulmonary fibrosis

Question 18

Patient presents with fatigue and erythema nodosum with a CXR suggestive of hilar lymphadenopathy. Sarcoidosis is suspected - what associated features might you anticipate?

Answer 18

1. Weight loss and night sweats
2. Hypercalcaemia
3. Polyarthritis

Question 19

What effect does emphysema do to residual volume?

Answer 19

Increases residual volume

Question 20

Regarding the follow-up of a lung nodule, when should it occur in the following scenarios, also comment on any further investigations required:

1. less then 4mm
2. above 4 - 6mm
3. above 6 - 8mm
4. above 8mm

Answer 20

For LOW risk patients (no smoking/no risk factors):

1. less then 4mm = no f/u
2. above 4 - 6mm = 12m +/- no f/u if NAD
3. above 6 - 8mm = 6-12m the 18-24m
4. above 8mm = 3,6,9,12 then 24m +/- CT/PET/Bx

If HIGH risk (smoking/other risk factors):

• then upstage every option e.g. less than 4mm = above 4 - 6mm
• NB: 6 - 8mm onwards ALL require close f/u +/- further investigations.

Question 21

50% of patient with COPD have reversible airway obstruction - what is the name for this condition?

Answer 21

Asthma-COPD overlap syndrome (ACOS)

Question 22

T/F: Inhaled corticosteroid increases the number of beta-2 receptors.

Answer 22

True

Question 23

Cystic Fibrosis has which inheritance pattern?

Answer 23

AR (Autosomal Recessive)

Question 24

What Abx regimen is required for a VAP (ventilator associated pneumonia) suspects in an ICU patient that was recently extubated:

1. Less than 5d in ICU and not in shock
2. More that 5d in ICU +/- shock

Answer 24

1. Less than 5d in ICU and not in shock

Tazocin (pipperacillin/tazobatam) IV for 7d - covers pseudomonas

2. More that 5d in ICU +/- shock

Tazocin (pipperacillin/tazobatam) - covers pseudomonas
+ Vancomycin IV - covers MDR organisms (e.g MRSA)
+ Gentamicin IV STAT - cover gram negatives

Question 25

Severe eosinophilic asthma may be treated with which monoclonal Ab? What is the MOA?

Answer 25

Mepolizumab = anti-IL5

Question 26

How is A-a gradient calculated?

Answer 26

A-a gradient = PAO2 - PaO2 Assuming sea level and patient being on RA: PAO2 = 150 - (PaCO2/0.8) Hence: A-a gradient = [150 - (PaCO2/0.8)] - PaO2 ABGs will give PaCO2 and PaO2 values

Question 27

Given a patient's age, how is A-a gradient estimated?

Answer 27

Estimated A-a gradient = (Age/4) + 4 Normal = below or equal to this estimate Example: 40yo --> Est. AaG = 40/4 + 4 = 14

Question 28

For the following scenarios is the A-a gradient likely to be normal or elevated: 1. High altitude 2. Hypoventilation (benzodiazepines) 3. Pulmonary fibrosis 4. PE 5. Right to left shunt 6. Left to right shunt

Answer 28

Normal (parenchyma unchanged): 1. High altitude 2. Hypoventilation (benzodiazepines) Elevated: 3. Pulmonary fibrosis - diffusion defect 4. PE - VQ mismatch 5. Right to left shunt - severe VQ mismatch due to bypass of lung Normal (trick) 6. Left to right shunt -

Question 29

Which 2 populations of COPD patients require pneumococcal vaccination?

Answer 29

1. Age > 65 yrs | 2. Young patient with chronic heart or lung disease

Question 30

T/F: LABA are superior to LAMA in reducing COPD exacerbation.

Answer 30

False - LAMA is superior to LABA

Question 31

T/F: In mild-moderate COPD ICS/LABA combinations are more effective than either component alone in reducing exacerbations and improving lung function.

Answer 31

False - this is true for moderate-severe COPD not mild-moderate.

Question 32

If a patient is NOT at sea level and on O2 therapy. What is the full A-a gradient equation?

Answer 32

A-a gradient = [ FiO2 x (Patm - PH2O) - PaCO2/0.8] - PaO2 At sea level and RA: A-a gradient = [150 - PaCO2/0.8] - PaO2 Where: PAO2 = FiO2 x (Patm - PH2O) - PaCO2/0.8 On RA: FiO2 = 21% = 0.21 At sea level: Patm = 760 mmHg Assuming 100% alveoli humidity: PH20 = 47 mmHg PAO2 = 0.21 x (760 - 47) = 149.73 = approx 150 When not at sea level and on O2 therapy --> insert your given Patm and FiO2 into the above equation.

Question 33

Which of the following are associated with CSA vs. OSA: 1. Elderly 2. Low BMI 3. Low Epworth Sleepiness Scale 4. Male sex 5. Self-reported heart failure

Answer 33

CSA patients are more likely to be: 1. Elderly 2. Low BMI 3. Low Epworth Sleepiness Scale 4. Male sex Thin male old man that is NOT sleep = CSA OSA patient are more likely to: 5. Self-reported heart failure