Ards (restrictive Acute) Flashcards
What causes surface tension in ards
The build ip of fluid in alveoli oncewases st causing alveolsr collqpse (oedema)
What event leads to this
Inflammation mainly neutrophilic in nature
What are some stats
Mortaoty is 40%
Prognosis deends on age, race (african/hispanic) and cause of arss
What is the radiology like
Hazy patrern and also increased consolidation and gg opacity
What can cause neutrophil attraction
Infection picked up by mac, aspiration eg via damage ti epi cells or attraction of neutrophils, transplants
What does neutrophil cause which allows oedema
Increased permeability of vascular and alveolar epithelium
What is rhe membrane called which is a build of debris, accumulated fibrosus and dead crlls
Hyaline membrane
What sort of events occur before ards
Trauma, shock, injuries or drug od
Which article discusses role of neutrophils in ards
Grommes et al 2011
After injurt what events allow neurrophils to get into alveoli
Margination and extravasation
Which release of cytokines after trauma by macrophages allows recruitment of neutrophils
Tnf, il1, il8, il6, il10
What sorts of things are released by neutorphil degranulation
Paf, leukotrienes (blth permeability)
Proteinases
Mmps
Ros
Which protease from neutrophils attacks surfsctant opsonins a and d which also reduce inflammation
Protease 3
Which mmp is most important by neutrophils causing inflammation and subsequent fubrosis in atds
Mmp9
What sort of things can ros do
Disrupt toght junctikns in epitheli, induce cell death causing inflammation, induce inflammasome
Which 3 cells seen hugh in arss in alveoli
Mac, neutrophils, rbc
What is in ordema fluid in high conc
Proteins
Why isn’t giving oxygen good for ards
Cant cross the fluid and distupted slveoli
What is given instead
Constant posiitive air pressure cpap
Wht does this do
Forms a positive pressure which inflates the alveoli and redcued collqpse from surfsce tension by fluid
Acure phase has been descirebd of ards. What is the subacute ohase (7-14 days)
Oedema restored, repair starts ti occur eg fibrosis laying down. Can also go weong
Where is fluid removed eventuslly
To microbasculsture or via lung lymphatics
Which 2 things releaxed by intact endothelium will later prevent neutrophil migration and activation
Lipoxins and resolvins
Why are alveolar macrophages good for resolution
Phagocytose inflammatory cells and the hyaline membrnae
Why can agba be used to investigate ards
Forms hypoxia
