The LycoVent a has a system of alarms to warn the clinical team of faults within the ventilator or in the VBS that would compromise patient safety. An alarm condition will be evident from an on-screen Alarm Prompt in the alarm banner at the top of the screen and will be accompanied by a flashing alarm beacon on top of the ventilator and an audible alarm tone. Additional information on each alarm is available on-screen by touching the Alarm Prompt.
Full details on alarms and alarm conditions are available here.
Alarms are graded depending on the criticality of the detected condition and the risk of harm to the patient:
Alarms are graded depending on the criticality of the detected condition and the risk of harm to the patient:
| Priority | Action | Tone | Interval (Sec) | Alarm Light |
|---|---|---|---|---|
| Low | Alerts the Operator to a potential problem | 27 | Solid On | |
| Medium | Prompt action required by the Operator | 19 | 1 Sec Flash Interval | |
| High | Immediate action required by the Operator | 7 | 0.25 Sec Flash Interval |
Alarms will escalate from Low to Medium to High if not acknowledged or repeats within a pre-defined period.
As the alarm system is itself critical to the safety of the patient there is an independent Watch Dog Controller that monitors for faults of the Main Controller where most of the alarms are generated. The Watch Dog also has a second and independent means of measuring pressure in the breathing circuit, and monitors the over-travel switches on the paddle arms.
If the Main Controller is faulted or the paddle arms have moved beyond their allowed range the ventilator will stop, display Watch Dog Alarm on the alarm ribbon on the screen and alarm at High Priority. When a Watch Dog alarm occurs the ventilator has detected a failure of a critical sensor or system and the patient should be ventilated manually till another ventilator is available.
Most alarms are intended to advise the clinical team of a change in the operating parameters monitored by the ventilator and it is the responsibility of the team to assess the clinical condition of the patient and adjust the alarm settings as required. However, for two of the alarm conditions – Pmax Exceeded and Plim Exceeded – the ventilator will react to reduce the risk to the patient while maintaining ventilation prior to the attendance of the team members.
PMAX – When the upper limit of Pmax (50 cm H2O) is detected by the ventilator it will alarm at High Priority, display P MAX exceeded on the alarm ribbon on the screen and reverse the arms to allow the pressure to reduce to the set PEEP value. At the start time of the next breath the ventilator will restart at a reduced volume and gradually increase volume to the preset value over approximately 5 breaths. PMAX can occur frequently if some combinations of TV and RR are entered with patients with low compliance and/or high resistance. The above strategy will allow the ventilator to continue to deliver ventilation at or below PMAX prior to the arrival of the team. The ventilator systems are operating normally under this alarm condition
PLIM – For PLIM (70cm H2O) to occur in the breathing circuit there has been a fault in the main controller pressure sensor as it should have triggered at 50 cm H2O. The ventilator will immediately alarm at High Priority, display Watch Dog Alarm in the alarm ribbon on the screen and reverse the paddle arms to allow the pressure to reduce to the PEEP value. At the start time of the next breath the ventilator will, if the flow sensor is operable, restart with the TV reduced to 50% of the previous setting (to a minimum of 200 mL) and the default settings for RR (12) and I:E ratio (1:2). The aim is to quickly reduce the parameters to achieve a pressure below PMAX so that the ventilator can maintain a minimum level of ventilation prior to the arrival of the team members.