Term
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Definition
ALI: PaO2/FiO2 <= 300
Mild ARDS between 200-300
Moderate ARDS between 100-200
Severe less than 100
**Bilateral infiltrates, PCWP < 18, failure not explained by cardiac reasons. |
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Term
| What increases ARDS mortality? |
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Definition
- Age
- Liver disease
- organ dysfunction
- mechanical ventilation
- Sepsis
- Latino or AA |
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Term
| What are characteristics of ARDS lung injury? |
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Definition
| Endothelial injury increases permeability --> influx of protein-rich fluid |
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Term
| What are the phases of ARDS? |
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Definition
- Exudative - first 4-7 days. Influx of protein fluid --> cytokine production. Type II cells, which produce surfectant, become compromised
- Proliferative - 7-21 days. Pneumocytes proliferate
- Fibrotic - >= 21 days. Fibroblast fill alveoli, loss of structure leads to fibrosis
- Recovery - resorption of edema, clearance of cells, restoration of type II cell function |
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Term
| What are risk factors for ARDS? |
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Definition
- Direct lung injury - pneumonia, aspiration
- Indirect injury - sepsis, severe trauma or shock w/ transfusion |
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Term
| How does ARDS present clinically? |
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Definition
- Timing - within one week of insult
- Chest imaging - bilateral infiltrates
- Edema - non-cardiac origin
- Oxygenation - PaO2/FiO2 between 0-300 |
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Term
| How is ventilation managed in ARDS? |
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Definition
- lung protective ventilation - 6 mL/kg of IBW (45.5 or 50 + 2.3*ht over 5')
- Traditional ventilation - 12 mL/kg * IBW
**Low TV standard of care, sedation sometimes needed |
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Term
| What are other ventilation strategies for ARDS? |
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Definition
- high-frequency oscillatory ventilation - a rescue to improve oxygenation
- Extracorporeal membrane oxygenation - in children, dialysis for the lungs |
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Term
| How are fluids managed for ARDS? |
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Definition
| Conservative fluid strategy does not improve mortality, but decreases ICU stay. |
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Term
| How do NMBAs work for ARDS? |
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Definition
| Act at NMJ to paralyze skeletal muscle - used to match patient with TV ventilation. Disads: weakness, tachyphylaxis. Bad adverse effects. |
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Term
| How do steroids work for ARDS? |
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Definition
On inflammatory component - proliferative phase. disads: infection risk, poor wound healing, hyperglycemia.
Current evidence does not support. |
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Term
| How are beta-agonists used for ARDS? |
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Definition
| Decreasing edema. Can use for bronchospasm, but evidence does not support. |
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Term
| How are statins used for ARDS? |
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Definition
| Decrease severity of sepsis. Not routinely used |
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Term
| How is inhaled NO used for ARDS? |
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Definition
| SM relaxation for short term relief and oxygenation |
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