ARDS- sarah Flashcards
what is ARDS
- capillary membrane that surrounds the alveoli sac leaks fluid into the sac
- decreased gas exchange
- collapse of alveoli from being overfilled with fluid
- hypoxemia (low o2 in the blood)
=all causing organs to suffer
what does ARDS develop from
-systemic inflammation that is either direct or indirect
direct causes
- things that affect the lungs directly
- PNA
- aspiration
- inhalation injury
- near drowning
- embolism
indirect causes
- things that don’t affect the lungs
- sepsis
- burns
- blood transfusions
- inflammation of pancreas
- drug overdose
3 phases of ARDS
- exudative
- proliferation
- fibrotic
exudative phase timing
-24 hours after injury
exudative phase pathO
-damaged capillary membrane –> fluid leaks in
(its protein rich).
- fluid then enters the intsretisium and then the sac = pulmonary edema
- surfactant cells are damaged causing the sac to not be stable and it will collapse with exhale = ATELECTASIS
- hyaline membrane will develop = less elastic lung = decreased lung compliance = VQ mismatch
hallmark sign of ARDS
- refractory hypoxemia
- no matter how much 02 giving oxygen never improves
proliferation timing
- 14 days after insult
proliferation phase
- influx of neutrophils, monocytes, lymphocytes, fibroblasts causing increased vascular resistance and pulmonary hypertension all causing even more decreased lung compliance from the fibrosis
- all causing decreased lung compliance and hypoxemia worsening
fibrotic time
- 3 weeks after the insult
fibrotic phase
- lung tissue is remodeled and fibrous= decreased compliance (hypoxemia, hypercapnia) causing systemic dysfunction from the decreased ventilation and oxygenation
- pulmonary hypetension
- will need mechanical ventilation and have poor prognosis
DX of ARDS
- CXR- white out bilaterally
- ABG
- Serum lactate will be increased
- CBC for less than 4 or over 10-12
- sputum and blood cultures
- coags
- electrolytes
- liver function tests
early signs of ARDS
- hard to notice
- normal to random crackles
- difference in breathing “air hunger”
- hyperventilation (increased RR) = decreased CO2, increased ph = respiratory alkalosis
late signs of ARDS
- refractory hypoxemia
- cyanosis
- change in mental status
- increased HR
- retractions
- crackles throughout
what is respiratory failure
- failure in gas exchange
- either oxygenation or ventilation (co2 removal)
what is ARDS
- caused by direct or indirect lung injury that causes progressive hypoxemia, infiltration, and fibrosis of lung tissue
hypoxemic RF
- PaO2 < 60 and normal pac02
hypercapnic RF
respiratory acidosis; Paco2 > 50 and ph less than 7.35
hypercapnia RF signs
- HA, confusion, decreased LOC, tachycardia, tachypnea, flushed skin
hypoxemia RF signs
- increased HR, RR, BP