There are several areas of discussion concerning ventilators in the pre-hospital and retrieval environment and the focus here is on complex versus simple ventilators.

One approach is to keep the ventilator as simple as possible, particularly in the relatively uncontrolled pre-hospital and retrieval environment, in which other issues may be distracting the user. With this in mind, many services have opted for simple gas-powered ventilators as pictured. There is no battery to charge and one simple pressure dial to read. The user can set a rate and a tidal volume and there are visual aids to prompt for paediatric settings. There is a demand switch (essentially to start ventilating), a visual aid to confirm oxygen is available and a variable upper pressure limit. Audio alarms are also a feature. A final switch allows either 45% or 100% oxygen. Positive end expiratory pressure (PEEP) is added to the external circuit. Such a straightforward set-up reduces the chance of error and is of particular benefit to services that transfer ventilated patients infrequently or who have a high staff turnover rate within the PHR team.