steroids comparison podcast

main role of inhaled corticosteroids (ICS) and what are 3 benefits of this

-effective control of inflammation

reduces mortality in asthma patients

reducing disease progression by reducing inflammatory driven airway remodelling

reducing frequency of acute exacerbations

when does late phase of bronchoconstriction occur

6-8 hours after initial attack

what causes immediate phase of bronchoconstriction cellularly

mast cell degranulation

what causes nocturnal asthma episodes vs what people think

nocturnal episodes may be continuation of earlier inflam response to allergens (progression into late phase) and not bed bugs

what is late phase associated with

eosinophil influx

under what conditions will tissue remodelling happen

over 3 asthma attacks a week

how does an inflammatory response happen starting from allergen exposure (2 steps)

-resident pulmonary macrophages and mast cells are activated

-these cells recruit eosinophils through release of mediators (and to a much lesser extent, in uncomplicated asthma, neutrophils)

after eosinophils are recruited, what does the presence of chronic inflammation in the lung cause

-damage to epithelial cell layer (causing epithelial cell shedding). this increases access to allergens and irritants to underlying sensory nerves (they’ll be more likely triggered to cause bronchoconstriction)

-subepithelial fibroblasts undergo hyperplasion, increasing collagen formation, contributing to loss of compliance in lung tissue - affects lung capacity and work needed to inflate lung

effect of goblet cell hyperplasia and overactivity in asthma

mucus plugging: increase and change in type of mucus secreted in lung → increase in mucus can cause blockage/obstruction of airway→ increases resistance to flow

effect of inflammation induced oedema

swelling of lung tissue (airway wall thickens and diameter decreases)

effect of decrease in lung diameter

increases resistance to flow, increasing severity of subsequent asthma attack

effect of increase in airway smooth muscle mass

decrease diameter of airway lumen

larger bronchoconstriction to any allergy response

how does corticosteroid Tx in asthma accelerate termination of inflammatory response

increases IL-10 levels

COPD pathophysiology vs astham (in COPD:)

-neutrophil acts like the eosinophil

lack of mast cell involvement

diff types of T cells