Asthma

Question 1

3 main characteristics of asthma

Answer 1

airway inflammation, reversible airflow obstruction, airway hyperresponsiveness

Question 2

describe allergic asthma pathogenesis (main cytokines, cells involved)

Answer 2

Th2 cells activated by allergens/dendritic cells, release IL-4, IL-5, IL-13, IL-4 stimulates B cells to produce IgE which prompts mast cell degranulation (LTs, histamine, PGs, cytokines): mucus, vasodilation, bronchoconstriction

IL-5 stimulates eosinophils

Question 3

how is non-allergic eosinophilic asthma different from allergic?

Answer 3

driven mainly by innate lymphoid cells rather than Th2, lack antigen receptors and dont produce IL-4/stimulate IgE and mast cells

still produce IL-5 and eosinophil activation

Question 4

describe pathogenesis of apsirin exacerbated respiratory disease (AERD)

Answer 4

inhibition of COX enzyme shunts eicosanoids towards LOX pathway, increased leukotriene production and bronchoconstriction

Question 5

list some Th2 high asthma types

Answer 5

AERD, allergic asthma, late-onset eosinophilic

Question 6

list some Th2 low asthma types

Answer 6

obesity associated, smoking/PMN, very late onset (esp women)

Question 7

pathogenesis of neutrophilic asthma

Answer 7

driven by Th17, recruitment of PMNs

Question 8

contrast eosinophilic and neutrophilic asthma

Answer 8

eos: mild,moderate, or severe
- Th2 or innate lymphoid
- steroid responsive

PMNs: severe asthma, Th17 cells, steroid resistant

Question 9

effects of eos and PMNs in airway wall

Answer 9

release cytokines, eicosanoids, peroxidases, ROS

amplifies inflammation, promotes hyperresponsiveness, promotes airway remodeling

Question 10

3 characteristics of airway remodeling in asthma

Answer 10

basement membrane thickening, smooth muscle hyperplasia, mucous metaplasia (lots of large goblet cells)

Question 11

why target IL-5 w/ drugs?

Answer 11

active in both allergic and non allergic eosinophilic asthma

Question 12

flow volume curve w/ asthma

Answer 12

lower peak flow, scooped out descent

Question 13

volume time curve w/ asthma

Answer 13

much lower FEV1, more linear and lower slope curve

Question 14

DLCO in asthma

Answer 14

usually normal or even elevated- maybe from hyperinflation

this is in contrast to emphysema, ILD, PAH which has reduced DLCO

Question 15

4 main asthma Sx

Answer 15

cough, wheeze, chest tightness, dyspnea

Question 16

physical exam findings

Answer 16

lower airway: wheeze, prolonged expiration

upper airway: enlarged turbinates, pale/inflamed mucosa

accessory muscle use, intercostal retractions, decreased breath sounds

eczema

Question 17

Dx tests for asthma (3 categories)

Answer 17

reversible obstruction: spirometry pre/post bronchodilation, peak flow variability (normally not variable)

hyperresponsiveness: methacholine challenge test
inflammation: exhaled NO (elevation indicates excess inflamed epithelial cells), induced sputum

Question 18

signs of asthma in induced sputum

Answer 18

charcot leyden crystals, curschmann spirals

eosinophils, creola bodies

Question 19

primary rescue med

Answer 19

albuterol sulfate

Question 20

benefit of spacer

Answer 20

improves drug delivery to lungs

Question 21

3 main controller meds

Answer 21

inhaled corticosteroids, ICS+long acting beta agonists (LABA), leukotriene modifier (montelukast)

Question 22

3 controller meds for more severe disease

Answer 22

long acting anti muscarinics (tiotropium), theophylline (PDE4 inhibitor), monoclonal antibodies (omalizumab, benralizumab, mepolizumab)

Question 23

what is dynamic hyperinflation

Answer 23

gas is trapped in alveoli from obstructed expiration, increases with each inhale

occurs with rapid RR (exercise, high RR setting on ventilator)

Question 24

describe auto peep

Answer 24

increased positive end expiratory pressure- incomplete expiration of prior breath causes pressure in lungs to be higher than atm

can be from ventilation that leads to dynamic hyperinflation

increases intra-thoracic pressure

Question 25

consequences of auto peep

Answer 25

can cause cardiogenic shock, increased intrathoracic pressure increases RV afterload, decreases RV output and LV preload- overall CO and MAP decline