What are in the options for withdrawing a patient from mechanical ventilation?

Updated: Sep 15, 2020
  • Author: Christopher D Jackson, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
  • Print


Weaning from mechanical ventilation is intended to shift the work of breathing from the ventilator back to the patient over time. An issue separate from discontinuing ventilator support is determining if the patient can maintain his or her airway and be extubated safely. The weaning process must ensure the patient's safety while avoiding undue delay that might increase the risk of ventilator-associated pneumonia.

The 3 general approaches to weaning are synchronized intermittent mandatory ventilation (SIMV), pressure-support ventilation (PSV), and a spontaneous breathing trial.

In SIMV, breaths are either a mandatory ventilator-controlled breath or a spontaneous breath with or without pressure support. The original intent of SIMV was to let the patient's respiratory muscles rest during the mandatory breaths and to work during the spontaneous breaths (see image below). Weaning is accomplished by decreasing the number of mandatory breaths, gradually increasing the workload of the respiratory muscles. Weaning is typically done by 2 breaths every 1–2 hours. The patient's heart rate, respiratory rate, and oxygen saturation indicate his or her ability to accomplish the work of breathing.

The pressure, volume, and flow to time waveforms f The pressure, volume, and flow to time waveforms for synchronized intermittent mandatory ventilation (SIMV).

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!