see also:

• assisted ventilation

• ventilator alarms deserve immediate attention
• look at the patient:
  • assess ABC:
    • is the airway in place?
    • is tubing connected?
    • is the chest rising and falling regularly?
    • is the patient a good colour?
    • check SaO2 and end-tidal PCO2 if available
• check ventilator alarm message
• if patient is hypoxic, distressed, sweaty, or not obviously ventilating, and solution is not immediately obvious, disconnect ventilator and commence manual ventilation with 100% oxygen.

• associated with a high end-inspiratory pressure (plateau pressure):
  • asynchronous breathing
  • a fall in lung compliance
    • endobronchial intubation
    • pneumothorax
    • abdominal distension
  • increased lung volume and raised intrinsic PEEP
    • air trapping due to inadequate expiratory time due to:
      • expiratory airflow obstruction eg. bronchospasm
      • high minute volume
      • fast respiratory rate
• associated with a normal or unchanged end-inspiratory pressure:
  • increased airway resistance
    • partially blocked ETT
    • bronchospasm

• ETT kinking
• ETT migrated to right main bronchus
• cuff herniation over end of ETT
• small airway size for ventilation required

• reduced lung compliance
• increased bronchial airway resistance (eg. bronchospasm)
• auto PEEP
• change in patient position

• water in circuit
• tubing kinked
• malfunctioning exhalation valve (nebulized medication can accumulate and block the valve)

• check ventilator fow setting in volume cycled modes - ? too high

• most likely cause is disconnection of circuit from patient or ventilator
• circuit leaks
• leak through chest tube
• cuff leak

• tidal volume has exceeded alarm limit
• check pressures

• extra flow added to circuit
• check todal volume or Pinsp setting
• flow sensor malfunction
• is the alarm set properly?

• patient has taken a large breath

• find and fix cause immediately

• pressure has been reached and volume lost
• Pinsp setting in PCV is too low
• disconnection of circuit
• leaks in circuit
• Vt not achieved in the time allocated in time cycled ventilation
• flow sensor malfunction
• is alarm set appropriately?

• patient taking small tdal volume:
  • patient lung compliance change - loss of Vt in PC mode
  • increased patient airway resistance - reaching high pressure limit and volume dumped
  • drowsy or sedated
  • exhaustion with respiratory failure
  • change in patient position
• patient being suctioned

• ETT position or obstruction
• ETT cuff complication

• usually oxygen cylinder has ran out or oxygen tubing has disconnected
• defective oxygen mixer
• defective oxygen sensor