UMEM Educational Pearls

With increasing critical care boarding and the opioid crisis leading to more intubations for overdose, extubation - which was once a very rare event in the ED - is taking place downstairs more often.  Prolonged mechanical ventilation is associated with a ton of complications, so it's important for the ED physician to be comfortable assessing extubation readiness.  There is no single accepted set of criteria, but most commonly used are some variant of the following:

• Reason for intubation (e.g. overdose, pneumonia, pulmonary edema, AMS, etc) has resolved
• Minimal vent settings - Typically FiO2 < 40%, PEEP <= 5
• Spontaneous breathing present (i.e. pt breathes with reasonable rate on PS, SIMV, VS, PPS, etc) and able to maintain reasonable pH and pCO2 on these settings
• Neuromuscular function adequate - Ask patient to lift head off bed
• Mental status adequate - Ask patient to give thumbs up or squeeze hands
• Secretions tolerable - Ask RN or RT for frequency of suctioning and sputum character.  Think twice about extubation if getting purulent, thick secretions every 15 minutes.
• Clinical course does not require further intubation (i.e. no immediate trips planned to OR, MRI; pt not hemodynamically unstable, etc.)

If the above criteria are met, two additional tests are frequently considered:

• Spontaneous Breathing Trial (SBT) - Typically done by placing pt on PS with low settings (0/0 to 5/5).  Let pt equilibrate (time of SBT is variable) on these settings, then calculate RSBI (RR/Vt). RSBI < 105 is traditionally considered acceptable for extubation.  Remember - lower is better.  Ask RT for this. 
• Cuff Leak Test - becoming less popular, but may consider in patients at risk for laryngeal edema (e.g. prolonged intubation, angioedema, etc). Historically thought to predict airway swelling, but data is mixed.  Ask RT for this.

And don't forget to consider extubating high risk patients directly to BiPAP or HFNC!

 

Bottom Line: For conditions requiring intubation where significant clinical improvement may be expected while in the ED (e.g. overdose, flash pulmonary edema, etc), be vigilant about, and have a system for, assessing readiness for extubation.

References

1. Souter MJ, Manno EM. Ventilatory management and extubation criteria of the neurological/neurosurgical patient. The Neurohospitalist. 2013;3(1):39-45. doi:10.1177/1941874412463944

2. Thille AW, Richard J-CM, Brochard L. Concise Clinical Review The Decision to Extubate in the Intensive Care Unit. doi:10.1164/rccm.201208-1523CI

3. Ouellette DR, Patel S, Girard TD, et al. Liberation From Mechanical Ventilation in Critically Ill Adults: An Official American College of Chest Physicians/American Thoracic Society Clinical Practice Guideline: Inspiratory Pressure Augmentation During Spontaneous Breathing Trials, Protocols Minimizing Sedation, and Noninvasive Ventilation Immediately After Extubation. Chest. 2017;151(1):166-180. doi:10.1016/j.chest.2016.10.036