Asthma, Peak Pressures, and the Ventilator

• In previous pearls, we have highlighted ventilator settings for the asthmatic, along with the differences between peak and plateau pressure measurements.
• When ventilating the asthmatic, pay attention to the ventilator settings placed by your respiratory therapist.
• In general, the respiratory therapist will set the ventilator to stop delivering tidal volumes when the peak pressure exceeds 40-60 cm H₂O.
• For asthmatics, this practice can result in very low tidal volumes.
• Thus, peak pressure limits must be set higher.
• As you know, high peak pressures have not been shown to be injurious, provided that the plateau pressure remains < 30 cm H₂O

References

Manthous CA. Avoiding circulatory complications during endotracheal intubation and initiation of positive pressure ventilation. JEM 2010; 38:622-31.