Alarms

Level 1 alarm examples

• Immediately life threatening

1. Electrical power loss

2. High pressure source gas loss

3. Exhalation valve failure

4. Excessive gas delivery to pt

5. Timing failure

Level 2 alarm examples

• Potentially life threatening

1. Circuit leak

2. circuit partially obstructed

3. Heater/humidification malfunction

4. I:E ratio inappropriate

5. Blender failure

6. Auto cycling

7. PEEP to high/low

Level 3 alarm examples

• Non life threatening but a potential source of patient harm

1. Changes in lung characteristics

2. Changes in ventilatory drive

3. High RR

4. Auto PEEP (air trapping)

High PIP

• warns against excessively high pressure

• set before pt attached to vent

• usually set around 40cmH20 but for US 30cmH2O

Low PIP

• warns against leaks or circuit disconnections

• set to 5cmH2O below PIP 10-20%

PEEP alarm

• warns against circuit leaks or inadvertent high PEEP conditions

• High PEEP set to 2cmH2O above

• Low PEEP set to 2cmH2O below

Low Paw pressure alarm

• warns against circuit leaks

• set to 5cmH2O below

Low and High volume alarms

• warning for circuit leaks or change in pts condition

• may be low/high VE or Vt or both

• Looks at pt exhaled volume

• ± 10 to 20% of measured value

RR rate alarm

• warning for changes in RR, apnea and drive to breath

• ± 10-20% of measured value

Apnea alarms

• warning for pt apnea

• time interval

• 20 seconds

FiO2 alarm

• warning of change in FiO2 of gas delivered to pt

• automatically determined by ventilator

• 10% above and 5% below set FiO2

EtCO2 alarms

• warning for low and high exhaled CO2

• can be in % or mmHg

• ±5tmmHg

Fisher Paykel Temperature Alarms

• heater unit malfunction and cable disconnects

• high and low temperature alarms

What to consider when setting alarms

Patient condition

• pathophysiology

• compliance resistance characteristics

• drive to breath

• pt comfort

Modes and parameters set

• when in volume ventilation careful attention to PIP alarm

• when in pressure ventilation careful of volume alarms

• modes that have dual purpose and adjust to pt condition

How to respond to ventilator alarms

1. Silencing alarm conditions

2. Level 1,2 or 3?

3. Is pt ventilating (chest rise, volume delivered)

4. Is pt in discomfort?

5. Are the vitals and non-invasive measurements stable?

6. Identify specific alarm condition (read it)

7. Is it ongoing or resolved?

8. Are they any obvious circuit interruptions

9. Has vent responded with a change ventilation

10. Trouble shoot and identify the cause

11. Implement change in therapy as needed

What to do if unsure of alarm condition

Manually ventilate then trouble shoot

Nuisance alarms

if alarm settings are too narrow

• do not indicate true alarm conditions

• better to set alarms in to narrow of range then to wide initially