SIMV- Synchronised Intermittent Mandatory Ventilation
Just as in AC mode, if the patient does not trigger a breath, the patient will receive a set volume/pressure breath, as in the first breath here.
However in SIMV when a triggered breath is initiated the patient determines the volume, which may be smaller than the non triggered breath.
So if the patient wants a lower volume during their spontaneous efforts they will receive a lower volume.
If the patient is taking good volumes during their spontaneous breaths, this may indicate that weaning might be possible.
If the spontaneous breaths are too small, then pressure support can be added to each breath to help the patient.
