Approximately 25,000 asthmatics are intubated each year
Mismanaged mechanical ventilation in asthma carries significant morbidity and mortality
One of the primary goals of ventilating the asthmatic is to allow for lung deflation
The most effective way to allow for lung deflation, and reduce hyperinflation, is to reduce minute ventilation (TV x RR)
Initial tidal volume settings should be 6 ml/kg of predicted body weight; if plateau pressures are > 30 cm H2O tidal volume should be decreased to 4 - 5 ml/kg
Reduced respiratory rates will also allow longer exhalation times; initial recommended rates are 6 - 8 breaths per minute
If plateau pressures are still high despite lowering tidal volume and respiratory rate, you can then shorten the inspiratory time to allow for longer exhalation
References
DeGiorgi A, White M. Ventilator management: maximizing outcomes in caring fo asthma, COPD, and pulmonary edema. Emergency Medicine Practice 2008;10(8):1-23.
