Pediatric Asthma Flashcards
DDx of wheezing in a child?
Is broad... Asthma. Chronic lung diseases of infancy. Congenital heart diseases. Fixed obstruction (e.g. vascular rings) Foreign body. CF. Immunodeficiency. GERD / aspiration. Infection.
Inflammation is key..
Right.
Odds of outgrowing wheezing at age 3 by age 6?
Is about 50-60%
Risk factors for wheezing being due to asthma that child won’t outgrow? (2 major, 3 minor)
Major: -Parental asthma. -Eczema. Minor: -Allergic rhinitis. -Wheezing apart from colds. -Eosinophilia.
What’s disynaptic growth?
How can you assess it?
Lung volumes and airway diameter may not increase at the same rate.
Can be assessed with FEV1/VC.
(this may have an genetic component… and affects likelihood of childhood asthma progressing to adult COPD)
How does birthweight correlate with adult lung function?
Higher birthweights -> higher FEV1 at age 60.
this is more significant than just… bigger, taller people having higher birthweights?
Aspects of airway remodeling in severe childhood asthma?
Basement membrane thickening, epithelial desquamation, goblet cell hyperplasia, subendothelial elastin deposition.
During performance of a normal flow curve (i.e. forced expiration), the equal pressure point…
A. Moves from central airways to peripheral airways.
B. Moves from peripheral airways to central airways.
C. Stays put.
A. Moves from central airways to peripheral airways.
This allows for Starling resistors to form at collapsible, non-cartilaginous parts of the airway, limiting how much one can exhale.
Does maximum flow during forced expiration increase with increased muscle strength?
No - once maximum flow is reached, the increased pleural pressure will just cause increased resistance in the airway.
Is the site of flow limitation more peripheral (i.e. worse) at lower or higher lung volumes?
It’s more peripheral/worse at lower lung volumes -> problems with the end of expiration.
(which makes the shape of the maximal expiratory flow curve to have a shoulder / drop off in obstructive lung disease)
How can you get PFTs on an uncooperative child?
Forced oscillometry of the respiratory system.
…which can determine impedance to flow based upon the airway’s resonant frequency. Using physics.
(Graph showed a lower natural/resonant frequency after a bronchodilator was given)
Are medications for pediatric asthma similar for children?
Yeah, pretty much.
Inhaled steroids, LABAs, and albuterol… with regimen depending on severity.
Can inhaled steroids sometimes just be given in exacerbations?
Yes… and this is potentially a good way to balance with negative side effects like height suppression.
We know that frequent asthma exacerbations are associated with more rapid declines in lung function… but do inhaled steroids slow this?
Maybe?
Inhaled steroids have been shown to reduce airway hyperresponsiveness (via methacholine testing)… but airway remodeling may still be taking place - because the sensitivity reverts to placebo levels upon discontinuation of the steroid.
