Flashcards in ARDS Deck (16)
What is ARDS? (think 3 key parts/characteristics)
(1) acute lung injury with (2) diffuse alveolar damage --> (3) pulmonary edema that is non cardiogenic
ARDS is usually seen unilaterally or bilaterally?
What are the 4 criteria for ARDS?
1. acute onset of respiratory failure
2. bilateral infiltrate on CXR
3. absence of LA hypertension
4. PaO2/PiO2 < 200 (<300 is mild injury)
What is the mechanism of lung injury in ARDS?
Activation of inflam mediators --> damage to capillary endo- and alveolar epi-thelial cells --> inc permeability --> influx of edema and inflam cells into airspace --> dysfunction of surfactant
What are the causes of ARDS?
- aspiration of gastric contents
- pulm contusion
- fat emboli
- near drowning
- inhalation injury
- drug overdose
- cardio-pulmonary bypass
- acute pancreatitis
- transfusion of blood products
What are the stages of ARDS
What factors increase the risk of death at the time of ARDS diagnosis?
1. chronic liver disease
2. non-pulmonary organ dysfuction
4. advanced age
What causes the severe hypoxemia assc with ARDS?
shunting of blood
In ARDS compliance is (inc or dec)
acutely decreased (due to hyaline memb? deposition)
What is PEEP? How does it help pts with ARDS?
Positive End Expiratory Pressure
it improves oxygenation by recruiting atelectatic alveoli and increases FRC by redistributing fluid to allow gas exchange
**counterbalances the pressure of fluid to keep alveoli open
What is the mortality of pts with ARDS? What is death usually caused by?
multi organ failure
When is pneumothorax seen in ARDS?
after 2nd week of illness
What reduces mortality in ARDS?
use of lower tidal volume during mechanical ventilation
-decreased lung injury and therefore decreased circulating inflam mediators
What can decrease the days spent on mechanical ventilation for pts with ARDS?
conservative fluid management
What can imporove oxygenation but does not improve mortality?
NO and prone ventilation