Mandatory minute ventilation
Mandatory minute ventilation (MMV) (also called minimum minute ventilation) is a mode of mechanical ventilation which requires the operator to determine what the appropriate minute ventilation for the patient should be, and the ventilator then monitors the patient's ability to generate this volume every 7.5 seconds. If the calculation suggests the volume target will not be met, IMV breaths are delivered at the targeted volume to achieve the desired minute ventilation[1]. Allows spontaneous breathing with automatic adjustments of mandatory ventilation to the meet the patient’s preset minimum minute volume requirement. If the patient maintains the minute volume settings for VT x f, no mandatory breaths are delivered. If the patient's minute volume is insufficient, mandatory delivery of the preset tidal volume will occur until the minute volume is achieved. The method for monitoring whether or not the patient is meeting the required minute ventilation (VE) is different per ventilator brand and model, but generally there is a window of time being monitored and a smaller window being checked against that larger window (i.e., in the Dräger Evita® line of mechanical ventilators there is a moving 20-second window and every 7 seconds the current tidal volume and rate are measured against to make a decision for if a mechanical breath is needed to maintain the minute ventilation). MMV is the most optimal mode for weaning in neonatal and pediatric populations and has been shown to reduce long term complications related to mechanical ventilation.[2]
Characteristics
- Type of breath — The ventilator increases the mandatory respiratory rate.
- Triggering mechanism — Increase of the mandatory respiratory rate is triggered when the actual minute volume is less than the preset minimal minute volume.
- Cycling mechanism — All mandatory breaths are volume cycled. Patients control their own spontaneous rates and volumes.
References
- ^ Scott O. Guthrie, Chris Lynn, Bonnie J. Lafleur, Steven M. Donn & William F. Walsh (October 2005). "A crossover analysis of mandatory minute ventilation compared to synchronized intermittent mandatory ventilation in neonates". Journal of perinatology : official journal of the California Perinatal Association 25 (10): 643–646. doi:10.1038/sj.jp.7211371. PMID 16079905.
- ^ Scott O. Guthrie, Chris Lynn, Bonnie J. Lafleur, Steven M. Donn & William F. Walsh (October 2005). "A crossover analysis of mandatory minute ventilation compared to synchronized intermittent mandatory ventilation in neonates". Journal of perinatology : official journal of the California Perinatal Association 25 (10): 643–646. doi:10.1038/sj.jp.7211371. PMID 16079905.