ARDS Flashcards
ARDS is a type of ____________ respiratory failure.
hypoxemic
What are the 4 most common causes of ARDS? (TAPS)
- trauma
- aspiration
- pneumonia
- sepsis
What are the Berlin diagnostic criteria for ARDS?
- precipitating cause/acute onset within 1 week
- bilateral diffuse infiltrates
- absence of LA hypertension (not cardiogenic)
- oxygenation criteria*
- mild = P:F <300
- mod = P:F <200
- severe = P:F <100
(all with PEEP >5)
What are the 2 common causes of direct ARDS?
- pneumonia
- aspiration of gastric contents
What are the 2 common causes of INdirect ARDS?
- sepsis
- severe trauma with shock and multiple transfusions
What 2 clinical findings exclude cardiogenic pulmonary edema?
- absence of S3 gallop
- absence of elevated JVP
What CXR excludes cardiogenic pulmonary edema?
- alveolar edema WITHOUT cardiomegaly
A BNP value of < ______ excludes cardiogenic shock and favors ARDS
< 100
- most likely not cardiogenic
- BNP >100 does not exclude ARDS
What are the 3 pathologic stages of ARDS?
- exudative stage
- proliferative stage
- fibrotic stage
What is the key pathologic finding in ARDS?
hyaline membrane formation
What is the difference between Type 1 and Type 2 alveolar epithelium cells?
- Type 1: 90% alveolar surface area and easily injured
- Type 2: 10% of alveolar surface area and more resistant to injury
What is the only definitive therapy proven to reduce mortality for ARDS?
ventilation with lower tidal volumes
What trial demonstrated a decreased ARDS mortality rate with lower tidal volume ventilation?
ARDSnet trial
What are the 3 major elements of the ARDSnet trial that make up the treatment for ARDS.
- low tidal volume ventilation with “permissive hypercapnia”
- limitation of pressures
- oxygenation with prescribed table of PEEP/FiO2
How do you set the tidal volume in LTVV?
- calculate predicted body weight
2. start at 8 cc/kg (PBW) and reduce to 6 cc/kg over 1-3 hours
ARDS is a _________ disease.
heterogeneous
What are 4 examples of ventilator induced lung injury?
- volutrauma
- barotrauma
- atelectrauma
- biotrauma
Why does LTVV work in treating ARDS?
prevents ventilator induced lung injury
The plateau pressure depends on _________.
elastance (1/compliance)
Plateau pressure is the equivalent to ________ pressure.
alveolar pressure
If plateau pressure is > ____ then you need to decrease TV by how much?
- > 30
- decrease TV by 1 cc/kg PBW
Why do we need to monitor the plateau pressure?
to prevent barotrauma (excess pressure)
What is the goal PaO2 with oxygenation in LTVV?
- PaO2 = 55-80
* adjust FiO2 and PEEP as necessary
In ARDS, what type of fluid fills alveoli?
Exudative
