Currently, the use of a portable mechanical ventilator is a mainstay of critical care patient transport via both air and ground. A small number of EMS agencies have introduced automatic transport ventilators as an addition to ALS protocols. These simplified ventilators provide more consistent minute volume than traditional positive pressure ventilation with a bag-valve device. There is also evidence that the use of automatic transport ventilators  may allow paramedics to complete other tasks related to patient care, as they are not directly involved in manual ventilation.
Prolonged manual ventilation with a bag-valve device is harmful and often increases patient mortality. The introduction of automatic transport ventilators into 911 responding ambulances could have significant impact on patient outcomes, particularly in rural areas with longer transport times.
Pre-hospital use of non-invasive ventilation methods (CPAP, BiPap, and PAV) has been shown to reduce in-hospital mortality rates. The addition of automatic transport ventilators with greater ability to customize settings for CPAP, BiPAP, and PAV would allow pre-hospital personnel to deliver respiratory support tailored to each patient's specific needs.