Respiratory Flashcards
Young patient with asthma is commenced on salmeterol, what is a potential side effect?
Paradoxically, it can cause an acute exacerbation of asthma possibly due to a hypersensitivity reaction.
True/False: where possible, asthmatics should have early intubation to improve outcomes.
False.
Avoid intubating asthmatics if possible, high pressures required and IV salbutamol/magnesium/aminophylline often required.
What base excess would trigger the need for bicarbonate?
less than -8
Restrictive lung disease from respiratory muscle weakness leads to what changes to the following parameters:
- FEV1
- FVC
- TLC
- RV
- RV/TLC
- TCO
- FEV1 - grossly lowered
- FVC - grossly lowered
- TLC - grossly lowered
- RV - high due to weakness
- RV/TLC - elevated, due to high RV
- TCO - not affected
OSA is risk factor for which 3 other conditions?
- CVA
- HTN
- Impaired glucose tolerance / Insulin resistance
What is decompression sickness?
- 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)
How is decompression sickness treated?
- Hydration
- O2-Rx (100%)
- Hyperbaric oxygen therapy
- Position the patient to improve forward blood flow
Hydrate - Oxygenate - Position
What is nitrogen narcosis?
- 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.
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.
True
What is the effect of anti-fibrotics Nintedanib and Pirfenidone on the natural history of idiopathic pulmonary fibrosis (IPF).
Slow further deterioration of lung function but does NOT reverse parenchymal lung damage.
What is Omalizumab?
When is it indicated?
- Ab that binds to free IgE and prevent cross-linking and allergic inflammation.
- Treats severe allergic asthma
What is Nintedanib?
When is it indicated (2)?
Inhibitor of multiple growth factors:
PDGFR (platelet-derived growth factor)
FGFR (fibroblast growth factor receptor)
VEGFR (vascular endothelial growth factor receptor)
Treatment for:
- IPF - antifibrotic effect
- Lung cancer - inhibits angiogenesis
What is Pirfenidone?
When is it indicated (1)?
Anti-fibrotic and anti-inflammatory due to inhibition of:
fibroblast proliferation
TGF-beta stimulated collagen production
IL-1
TNF-alpha
Treatment for IPF.
What is Montelukast?
When is it indicated (2)?
Leukotriene receptor antagonist (LTRA)
Treatment of:
- Asthma
- Seasonal allergies
What is Mepolizumab?
When is it indicated (1)?
mAB to IL-5
Treatment of severe eosinophilic asthma
Patient has cystic fibrosis and requires a lung transplant. Single or bilateral?
Bilateral - single lung transplant is CONTRAINDICATED in cystic fibrosis.
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?
Pulmonary fibrosis
Patient presents with fatigue and erythema nodosum with a CXR suggestive of hilar lymphadenopathy. Sarcoidosis is suspected - what associated features might you anticipate?
- Weight loss and night sweats
- Hypercalcaemia
- Polyarthritis
What effect does emphysema do to residual volume?
Increases residual volume
Regarding the follow-up of a lung nodule, when should it occur in the following scenarios, also comment on any further investigations required:
- less then 4mm
- above 4 - 6mm
- above 6 - 8mm
- above 8mm
For LOW risk patients (no smoking/no risk factors):
- less then 4mm = no f/u
- above 4 - 6mm = 12m +/- no f/u if NAD
- above 6 - 8mm = 6-12m the 18-24m
- 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.
50% of patient with COPD have reversible airway obstruction - what is the name for this condition?
Asthma-COPD overlap syndrome (ACOS)
T/F: Inhaled corticosteroid increases the number of beta-2 receptors.
True
Cystic Fibrosis has which inheritance pattern?
AR (Autosomal Recessive)
What Abx regimen is required for a VAP (ventilator associated pneumonia) suspects in an ICU patient that was recently extubated:
- Less than 5d in ICU and not in shock
- More that 5d in ICU +/- shock
- Less than 5d in ICU and not in shock
Tazocin (pipperacillin/tazobatam) IV for 7d - covers pseudomonas
- 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
Severe eosinophilic asthma may be treated with which monoclonal Ab?
What is the MOA?
Mepolizumab = anti-IL5
How is A-a gradient calculated?
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
Given a patient’s age, how is A-a gradient estimated?
Estimated A-a gradient = (Age/4) + 4
Normal = below or equal to this estimate
Example: 40yo –> Est. AaG = 40/4 + 4 = 14
For the following scenarios is the A-a gradient likely to be normal or elevated:
- High altitude
- Hypoventilation (benzodiazepines)
- Pulmonary fibrosis
- PE
- Right to left shunt
- Left to right shunt
Normal (parenchyma unchanged):
- High altitude
- Hypoventilation (benzodiazepines)
Elevated:
- Pulmonary fibrosis - diffusion defect
- PE - VQ mismatch
- Right to left shunt - severe VQ mismatch due to bypass of lung
Normal (trick)
6. Left to right shunt -
Which 2 populations of COPD patients require pneumococcal vaccination?
- Age > 65 yrs
2. Young patient with chronic heart or lung disease
T/F: LABA are superior to LAMA in reducing COPD exacerbation.
False - LAMA is superior to LABA
T/F: In mild-moderate COPD ICS/LABA combinations are more effective than either component alone in reducing exacerbations and improving lung function.
False - this is true for moderate-severe COPD not mild-moderate.
If a patient is NOT at sea level and on O2 therapy.
What is the full A-a gradient equation?
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.
Which of the following are associated with CSA vs. OSA:
- Elderly
- Low BMI
- Low Epworth Sleepiness Scale
- Male sex
- Self-reported heart failure
CSA patients are more likely to be:
- Elderly
- Low BMI
- Low Epworth Sleepiness Scale
- Male sex
Thin male old man that is NOT sleep = CSA
OSA patient are more likely to:
5. Self-reported heart failure
