Continuous mandatory ventilation (formerly known as Assist Control or AC) is a mode of ventilation where breaths are delivered based on set variables. The patient may initiate breaths by attempting to breathe. Once a breath is initiated, either by the patient or by the ventilator the set tidal volume is delivered. Continuous mandatory ventilation used to also be called Volume Control or Assist Control Volume Control (AC/VC), though this is no longer recommended. Since nomenclature of mechanical ventilation is only recently standardized there are many different names that historically were used to reference CMV but now reference Assist Control.Names such as: volume control ventilation, and volume cycled ventilation in modern usage refer to the Assist Control mode.

Controlled mechanical ventilation in its original form had no patient sensitivity. A breath set was a breath delivered. Continuous mandatory ventilation was created out of the need for patient-initiation in breaths. Fundamentally, Continuous mandatory ventilation is controlled mechanical ventilation (CMV) with a sensitivity for patient breathing. The use of controlled mechanical ventilation requires the patient be completely unconscious, either pharmacokinetically or otherwise in a coma.

 

Continuous mandatory ventilation (formerly Assist Control or AC) is associated with profound diaphragm muscle dysfunction and atrophy.Continuous mandatory ventilation is no longer the preferred mode of mechanical ventilation.