The Extubation Series: Part 3, Extubate to What?

NIV

Suppose your patient presents with atelectasis or has a history of sleep apnea, you can extubate to CPAP.  If you suspect your patient will be unable to maintain adequate VE without excessive WOB, then extubating to NIV is your best option.  This allows the clinician to match the patient’s ventilatory demand.  The COPD population, as well as hypercapneic obesity syndrome patients  would benefit from NIV.  However, NIV is not tolerated by all patients due to mask intolerance and compliance.  

Studies

One small-scale study by Nava et al., randomized 97 participants who required more than 48 hours of mechanical ventilation. These participants passed their SBT and presented with one of the factors associated with a high risk of extubation failure.  The study compared extubation to NIV versus standard oxygen therapy.  NIV was applied for 8 hours per day for 48 hours.  The group receiving NIV had a lower reintubation rate; however, mortality and hospital length of stay were not significantly different between the groups.  

Although noninvasive ventilation may prevent post-extubation respiratory failure in patients with high risk, there are still no large-scale studies showing the significant reduction in reintubation from NIV use compared to standard oxygen therapy.  However, the most recent guidelines from the American Thoracic Society and the American College of Chest Physicians recommend using NIV to prevent post-extubation respiratory failure in patients at high risk of extubation failure.  

HFNC

As a clinician, I would extubate to HFNC when hypoxemia, not the result of atelectasis or severe ARDS, is present.  The benefit of HFNC is constant FiO2, CO2 washout of upper airway anatomical dead space, ultimately reducing VE, optimal gas conditioning, and potential physiological effects of low PEEP. HFNC has the advantage of comfortability compared to NIV and CPAP.

Studies 

A small-scale study comparing HFNC to standard oxygen therapy by Fernandez et al. randomized patients immediately after extubation who were at high risk of reintubation.  The analysis was stopped early because of low recruitment.   Reintubation occurred in 9 participants in the HFNC group compared to 12 reintubations in the standard oxygen therapy group.  However, there were no differences in hospital length of stay or mortality.  

One large-scale randomized study comparing the application of HFNC to NIV post-extubation reported that HFNC was non-inferior to NIV in preventing reintubation in patients at high risk of reintubation.  Using HFNC with NIV is superior to HFNC alone and may further improve gas exchange and the work of breathing, ultimately avoiding reintubation.   

Conclusion 

All three therapies can end in respiratory failure requiring reintubation.  Monitor your patient’s response to therapy.  If your patient’s clinical status has not improved, you may want to think of reintubating.  Delayed intubation in patients who are not responding leads to mortality.  

Even though extubating to NIV and HFNC in high-risk patients may show benefits there are more large-scale studies needed.