Mechanical ventilation is provided using two basic methods: volume controlled modes and pressure controlled modes. As the name implies, volume controlled modes are designed to achieve a programmed tidal volume with each ventilation at whatever pressure is necessary within a safe limit. Pressure controlled modes are targeted at delivering ventilations until a set pressure is achieved, with tidal volume being regulated by lung compliance, and airway resistance. All types of mechanical ventilation use some combination of these two basic modes.

Ventilators also allow for adjustment of positive end-expiratory pressure (PEEP), and control over the fraction of inspired oxygen (FiO2). Delivering a more precise FiO2 can better ensure an adequate amount of oxygen is available to the patient, without causing oxygen toxicity or hyperoxia.

Standard initial settings for volume delivery usually fall between 6-8 mL/kg, with a maximum recommended volume of 10 mL/kg. Pressure settings usually max out at 20 cm H2O, but may vary by machine. The standard recommended setting for positive end expiratory pressure is anywhere from 0-15, depending on patient complaint. FiO2 levels are also patient dependent.

Many ventilators also provide settings for non-invasive ventilation methods, such as continuous positive airway pressure (CPAP), bi-level positive airway pressure (BiPAP), and proportional assist ventilation (PAV). Non-invasive methods of ventilation are useful in a variety of conditions where respiratory failure is imminent.

While EMS personnel commonly use CPAP in the prehospital setting, BiPAP capabilities provide more customization for varied patient presentations. PAV settings allow for dynamic inspiratory assistance in patients experiencing respiratory difficulties in order to achieve pre-set tidal volume targets.