Ventilation Strategy

Question 1

Ventilation Strategy in ARDS for Tidal Volume and Driving pressure?

Answer 1

• Low Tidal Volumes ( 4-6ml/kg predicted body weight to maintain plateau pressure < 30 cmH20
• Goal Driving Pressure (Pplat-PEEP) <13 cmH20

Question 2

Mechanism in which Prone position improves V/Q?

Answer 2

• Increase in Lung volume by reducing lung compression
• Redistribution of perfusion
• Recruitment of dorsal lung with more homogeneous distribution of ventilation and perfusion
• reduces ventral to dorsal transpulmonary pressure difference
• Trial looking at this was (PROSEVA)

Question 3

Dynamic Compression of the Airways

Answer 3

• Limits flow rate during a forced expiration.
• Causes flow to be independent of effort.
• May limit flow during normal expiration in some patients with COPD.
• Is a major factor limiting exercise in COPD.

Question 4

Increasing the Peak Inspiratory flow rate will?

Answer 4

Decreased Inspiratory time, increase expiratory time and decrease the I:E Ratio.

Question 5

How do you correct stress index if upward concavity of pressure-time curve is note on vent? ( Stress index >1, Overdistension)

Answer 5

Decrease Tidal Volume

Question 6

If flow curve is showing stress index < 1 (Downward concavity of pressure-time curve) what ventilator change can you do to Normalize the flow to a more linear pressure-time curve?

Answer 6

Increase PEEP