I. Precautions

  1. Heed Ventilator Alarms
    1. Treat as critical incident that needs rapid response and evaluation
    2. If problem cannot easily be detected, disconnect Ventilator and provide bag-valve-mask PPV while troubleshooting
      1. Provide High Flow Oxygen (with PEEP valve if needed)
  2. High Peak pressure and Ventilator Alarms
    1. High airway resistance (e.g. Asthma, mucous plugging) can result in exceeding peak pressure
      1. The Ventilator stops ventilating and alarms immediately when peak pressure exceeds the pressure limit
      2. Pressure limit set too low for current peak pressures results in hypoventilation (with hypercarbia risk)
      3. Pressure limit typically defaults to 40 cm H2O but can be increased if peak pressure is high
    2. However plateau pressure (alveolar pressure) is a risk of barotrauma, NOT peak pressure
      1. To obtain plateau pressure, press and hold the "inspiratory hold" button through a ventilation
      2. Plateau pressure >30 cm H2O (barotrauma risk)
        1. Consider causes of increased plateau pressures
        2. Consider decreasing Tidal Volume and Respiratory Rate
      3. Plateau pressure <30 cm H2O (despite increased peak pressure)
        1. Consider increasing the Ventilator pressure limit
        2. Reduce airway resistance (suctioning, check ET Tube position, Bronchodilators)
  3. References
    1. Weingart in Majoewsky (2013) EM:Rap 13(1): 6-7

II. Causes: Acute Respiratory Deterioration on Ventilator (DOPES Mnemonic)

  1. Dislodged or displaced Endotracheal Tube or cuff
  2. Obstructed Endotracheal Tube (e.g. mucous plugging, blood in tube)
  3. Pneumothorax
  4. Equipment failure (Ventilator, tubing)
  5. Stacking of breaths (incomplete exhalation in Asthma or COPD)

III. Causes: Acute Respiratory Deterioration on Ventilator (categorized by peak inspiratory pressure)

  1. Peak Inspiratory Pressure Decreased
    1. Air Leak
    2. Hyperventilation
  2. Peak Inspiratory Pressure Unchanged
    1. Pulmonary Embolism
    2. Extrathoracic problem
  3. Peak Inspiratory Pressure Increased
    1. Plateau Pressure unchanged: Airway Obstruction
      1. Aspiration
      2. Bronchospasm
      3. Secretions
      4. Endotracheal Tube obstruction
    2. Plateau Pressure increased (>30 cm H2O): Decreased Compliance
      1. Abdominal distention
      2. Asynchronous breathing
      3. Atelectasis
      4. Auto-PEEP
        1. Tachypnea is primary problem
        2. Excessive Respiratory Alkalosis
      5. Pneumonia
      6. Pneumothorax
      7. Pulmonary edema
      8. Air trapping (Asthma)
        1. Consider lowering Tidal Volume and Respiratory Rate to allow greater exhalation

IV. Management: Trouble-Shooting Inadequate Ventilation or Oxygenation (DOTTS Mnemonic)

  1. Disconnect the Ventilator
    1. Listen over the ET Tube for hissing sound
    2. Hissing suggests release of hyperinflated air from breath stacking
    3. If hissing present, apply anterior chest pressure gently for 10 seconds to assist with further release of stacked air
  2. Oxygenation
    1. Connect Ambu Bag with 100% FIO2 and provide manual Positive Pressure Ventilation
    2. Assess lung compliance
      1. Difficult PPV suggests Endotracheal Tube obstruction or decreased lung compliance (e.g. pulmonary edema, Pneumothorax)
      2. Easy PPV suggests air leak (e.g. deflated ET cuff or dislodged tube)
  3. Tube Position or Function
    1. Compare tube position to prior reading
    2. Pass suction catheter via the Endotracheal Tube to relieve mucous plugging
  4. Tweak the Ventilator setting
    1. Consider breath stacking (auto-PEEP)
    2. Consider lowering Respiratory Rate and Tidal Volume
  5. Sonography
    1. See Lung Ultrasound for Pneumothorax (Sliding Lung Sign)
    2. See Lung Ultrasound
    3. See Blue Protocol (Lichtenstein Dyspnea Evaluation by Ultrasound Protocol)
    4. See Volpicelli Dyspnea Evaluation with Ultrasound Protocol
    5. Studies are underway in 2013 to determine if Ultrasound can reliably determine ET position in relation to carina
  6. References
    1. Mallemat and Swadron in Herbert (2013) EM:Rap 13(12): 11

V. References

  1. Marino (1991) ICU Book, Lea & Febiger, p. 368

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