Continuous mandatory ventilation
Volume Controlled Continuous Mandatory Ventilation — (VC-CMV) is a mode of mechanical ventilation where breaths are delivered based on set variables. The patient may initate breaths by attempting to breathe. Once a breath is initated, either by the patient or by the ventilator the set tidal volume is delivered.
- Terms also used (though not preferred)
Assist/Control, A/C, CMV, Volume Assist/Control, Volume Control, Volume Limited Ventilation, Volume Controlled Ventilation, Controlled Ventilation, Volume Targeted Ventilation.
Controlled Mechanical Ventilation
CMV — Controlled Mechanical Ventilation (also called Controlled Volume Control) is the original name for Assist Control. When the addition of a patient initiated breath was added to the mode, Assist Control effectively replaced CMV entirely. Fundamentally, CMV is a volume-controlled mode where the tidal volume and frequency are set to deliver a minute volume with a complete disregard for patient effort.
The use of CMV requires the patient be completely unconscious, either pharmacokinetically or otherwise in a coma.
- Other terms used to represent CMV
Since nomenclature of mechanical ventilation is only recently becmoe standardized[1] there are many different names that historically were used to reference CMV but now reference Assist Control.[1] Names such as: volume control ventilation, and volume cycled ventilation in modern usage refer to the Assist Control mode.
Assist Control
VC-CMV — Most commonly referred to as Assist Control (AC) is a mode of ventilation where breaths are delivered based on set variables. The patient may initate breaths by attempting to breathe. Once a breath is initated, either by the patient or by the ventilator the set tidal volume is delivered. Assist Control is also called Volume Control or Assist Control Volume Control (AC/VC).
This mode was created out of the need for patient-initiation in breaths. Fundamentally, AC is controlled mechanical ventilation (CMV) with a sensitivity for patient breathing.
The variables required in AC are: tidal volume (VT), respiratory rate (f), flow rate and trigger sensitivity (for sensing patient effort). Additional variables like peak-end expiratory pressure (PEEP) and pressure support (PS) may be added for additional support.
- Expected outcomes and considerations
Assist Control is associated with profound diaphragm muscle dysfunction and atrophy.[2] AC is no longer the preferred mode of mechanical ventilation.[3]
See also
- Modes of mechanical ventilation
- Volume Controlled Continuous Mandatory Ventilation
- Volume Controlled Intermittent Mandatory Ventilation
- Pressure Controlled Continuous Mandatory Ventilation
- Pressure Controlled Intermittent Mandatory Ventilation
- Continuous Spontaneous Ventilation
Reference
- ^ a b Chatburn RL. Classification of ventilator modes: update and proposal for implementation. Respir Care 2007; 52:301–323.
- ^ Sassoon CS, Zhu E, Caiozzo VJ (2004). "Assist-control mechanical ventilation attenuates ventilator-induced diaphragmatic dysfunction". Am J Respir Crit Care Med. 170 (6): 626–32. doi:10.1164/rccm.200401-042OC. PMID 15201132.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Macintyre N (2011). "Counterpoint: Is Pressure Assist-Control Preferred Over Volume Assist-Control Mode for Lung Protective Ventilation in Patients With ARDS? No". Chest. 140 (2): 290–2. doi:10.1378/chest.11-1052. PMID 21813526.