Answer to Critical Care Question

This patient is ready for extubation.  Everyone has their own magic numbers they want to see on the vent before they think about extubating a patient, but mine are:

  • Pressure support mode
    • every breath is initiated by the patient and only supported by the vent
  • Pressure support ≤ 8 cmH2O
    • This will be enough support to overcome the resistance in the circuit.
  • PEEP ≤ 7 cmH2O
    • Physiologic PEEP of the epiglottis is 5 cmH2O
  • FiO2 ≤ 40%
    • No more supplemental oxygen than what would be given via nasal cannula or open face mask
  • Stable ABG on these settings for at least 2 hours
  • A&Ox3 and following commands
    • Patients need to be able to participate in pulmonary toilet after the tube comes out

These are basic principles and there are many variables that go into deciding to extubate a patient.  LITFL does a great review here and goes through a very systematic approach.

Once this is all good, then you can perform a few bedside tests or measurements that can help predict success of extubation.

  1. Rapid Shallow Breathing Index (RSBI)
    • Respiratory Rate / Vt (L)
    • < 105 predicts successful extubation
  2. Negative Inspiratory Force (NIF)
    • Measurement of the maximal inspiratory pressure
    • This is a great measurement of a patient’s ability to generate an adequate tidal volume once extubated.
    • > -20 cmH2O predicts successful extubation

Prediction of Successful Extubation. The ICU Book.

Prediction of Successful Extubation. The ICU Book.

Great post from Intensive Blog on “The Art and Science of Extubation


  3. Fadaii, A.  Assessment of rapid shallow breathing index as predictor for weaning in a respiratory care unit.  Tanaffos.  2012;11(3):28-31.
  4. Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. N Engl J Med. 1991;324(21):1445–50. [PubMed]

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