Acute status asthmaticus

Question 1

Ventilation strategy

Answer 1

Use a small tidal volume, 5-7ml/kg

Use a slow respiratory rate, 10-12 breaths per minute (or even less!)

Use a long expiratory time, with I:E ratio 1:3 or 1:4

Increase inspiratory flow rate to maximum.(60-80L/min).

Set peak air way pressure to 40-45cmH20 or higher

Lower extrinsic PEEP to 0.

Question 2

Dynamic hyperinflation

Answer 2

slow expiratory airflow -> incomplete exhalation of gas during normal expiratory times -> gas trapping

Question 3

Assessing DHI in the Mechanically Ventilated

Answer 3

Plateau Pressure: The best assessment of DHI. Aim < 25-30cmH2O.

PEEPi: underestimate. Due to widespread airway closure.

Peak air pressure: No useful. This is sum of pressures required to overcome the elastic recoil pressures of resp. system and airway resistance.