Define acute lung injury
- 1. PaO2/FiO2 < 300
- 2. Bilateral pulmonary infiltrates
- 3. PaO2 pressure < 18mmg Hg or no clinical evidance of left heart failure.
Acute lung injury in which PaO2/FiO2 <200
A (acute), R (restictive), D (Diffuse), S (shunt O2)
Causes of ARDS
Direct: aspiration, pneumonia and inhalation
Indirect: Sepsis, pancreatitis, transfusion, truama
Death from ARDS?
uncomman. First 3 day its the underlying cause, After 3 days its sepsis.
Always aggressively treat the underlying cause.
Keep patient slightly hypovolumic (but enough to keep perfusion with low lactate. Target CVP
And appropriate vent support
Vent support setting for ARDS
- Assist control / volume cycle
- FiO2 : 1 then titrate down to <0.6
- low tidal volumes: start at 8ml -> 6ml/Kg
- Plateau pressure <30 mmHg
- Inspiratory flow 60L/min
- May try increase ratio ventilation
- Permissive Hypercapnia
- if acidotic then -> increase RR, increase TV, NaCO3
7.15-7.30 -> increase RR till 35, or NCo3 or increase TV 1ml/kg