Vent Alarm or Sudden Distress Algorithm

1 Is the patient in distress or is SpO₂ falling?

Yes: distressed or desaturating → step 2No: a pressure alarm only → step 3

2 Disconnect and bag with 100% O₂

• Call for help
• Feel how easy the bag is to squeeze
• Check end-tidal CO₂

Better off the ventilator → step 4Not better, or hard to bag → step 5

3 High pressure alarm: measure the plateau

• Inspiratory hold on a volume breath

High peak, normal plateau → step 6High peak and high plateau → step 7Expiratory flow does not reach zero → step 8

4 Equipment problem

• Ventilator settings, circuit leaks or disconnects, oxygen supply
• Keep bagging while the circuit or ventilator is replaced
• Asynchrony: adjust settings, treat pain and agitation

End of this path.

5 Pass a suction catheter

• Check tube depth at the teeth or lips
• Look for a waveform on capnography

Catheter will not pass or no CO₂ waveform → step 9Passes and CO₂ waveform present → step 10

6 Airway resistance

• Secretions: suction
• Biting or kinked tube: bite block, straighten
• Bronchospasm: bronchodilator

End of this path.

7 Low compliance

• Pneumothorax, mainstem intubation, pulmonary edema, ARDS, tense abdomen
• Check tube depth and breath sounds; chest x-ray

End of this path.

8 Auto-PEEP (air trapping)

• Lower the rate, shorten inspiration, treat bronchospasm
• Measure with an end-expiratory hold

End of this path.

9 Displaced or obstructed tube

• Deflate the cuff and look; bag-mask ventilate if the tube is out
• Prepare to reintubate
• Biting: bite block and sedation

End of this path.

10 Pneumothorax or other lung cause?

• One-sided breath sounds, rising airway pressures, falling BP: tension pneumothorax
• Otherwise: bronchospasm, mucus plug, auto-PEEP, worsening lung disease

Signs of tension pneumothorax → step 11No: check peak and plateau → step 3

11 Decompress now

• Needle or finger decompression, then a chest tube
• Do not wait for the x-ray

End of this path.