APVsimv stands for adaptive pressure ventilation with synchronized intermittent mandatory ventilation. This mode is also called SIMV+, synchronized intermittent mandatory ventilation plus. The APVsimv mode combines attributes of the APVcmv and SPONT modes, delivering volume-targeted mandatory breaths or pressure-supported spontaneous (patient-triggered) breaths.
APVsimv mode ensures that the set target volume is delivered during the mandatory breaths. After the mandatory breath is delivered, the patient is free to take any number of spontaneous breaths for the remainder of the APV breath interval.
The ventilator uses the Plimit setting () (high Pressure alarm limit minus 10 cmH2O) as a safety boundary for its inspiratory pressure adjustment, and does not exceed this value. An exception is Sigh breaths, when the ventilator may apply inspiratory pressures 3 cmH2O below the high Pressure alarm limit.
Each breath interval includes mandatory time (Tmand) and spontaneous time (Tspont).
- If the patient triggers a breath during Tmand, the ventilator immediately delivers a mandatory breath.
- If the patient triggers a breath during Tspont, the ventilator delivers a spontaneous pressure-supported breath.
If the patient does not trigger a breath during Tspont, the ventilator automatically delivers a mandatory breath at the end of Tmand.
In this mode, parameters for both mandatory and spontaneous breath types are set.
- The tidal volume (Vt) setting defines the delivered volume of mandatory breaths.
Rate and I:E () define the timing of the breath cycle for mandatory breaths. - For spontaneous breaths, Psupport () defines the pressure support above PEEP.
ETS defines the inspiratory timing of the breaths. The inspiratory time can also be limited by TI max ().
Control parameters for APVsimv or SIMV+:
Vt
Rate
Sigh
PEEP/CPAP
I:E ()
Psupport ()
Oxygen
P-ramp
Trigger
ETS