Table 4.

Alarm conditions.

Parameter	Priority level	Description
Electrical power lost	High	The 12 V electrical power is lost. The ASVa cannot run in this state, but the alarms will be powered by the standby battery.
Maximum pressure	High	The patient-circuit pressure has exceeded the maximum pressure parameter. This indicates there may be a problem with the PIP valve, the hoses, the endotracheal tube, or the patient. The ASV continues running, but stops the compression of the bag at maximum pressure on each cycle.
Pressure low	High	The patient-circuit pressure is low. Possible reasons are the ASV has stopped due to loss of the pneumatic system or a disconnected patient hose.
Volume low	High or medium	In PC-ACb mode, this is a high alarm when the volume drops below 250 mL. In VC-ACc mode this is a medium alarm when the volume drops below 80% of maximum volume. The expected volume has not been met, possibly due to disconnected or kinked hose.
Volume high	Medium	In VC-AC mode, this is a medium alarm when the pressure exceeds 120% of maximum volume.
9 V battery low	Medium	The 9 V standby battery must be replaced to prevent failure of the Electrical Power Lost high-priority alarm. However, in the absence of this 9 V battery’s power, the ASV continues running normally.

^aASV: acute-shortage ventilator.

^bPC-AC: pressure-controlled assist control.

^cVC-AC: volume-controlled assist control.