Following extubation, noninvasive respiratory support might help patients avoid reintubation.  To date, BiPAP is supported by the greatest volume of evidence in this situation.  However, it’s often impossible to persuade patients to wear the BiPAP mask, making post-extubation BiPAP a logistic nightmare.  It would be nice if there were a RCT comparing HFNC vs. BiPAP…

Hernandez 2016-II:  Effect of post-extubation high-flow nasal cannula vs. noninvasive ventilation on reintubation and postextubation respiratory failure in high-risk patients: A randomized clinical trial.

This is a prospective multicenter RCT comparing HFNC vs. BiPAP among 605 patients at high risk for reintubation.  Being “high risk” for reintubation was defined broadly, as anyone with at least one of the following characteristics:

• age > 65
• APACHE-II > 12 at extubation
• BMI > 30
• difficulty weaning
• intubation for over a week
• two or more comorbidities
• intubation for heart failure
• significant COPD
• high risk of laryngeal edema (two or more of the following criteria: female gender, intubated for at least three days, difficult intubation)
• weak cough or frequent suctioning requirement

Patients were randomized to receive HFNC vs. BiPAP for 24 hours after extubation.  HFNC titrated to the highest flow rate that the patient could tolerate.  BiPAP settings were adjusted to target a respiratory rate of 25 breaths/minute, adequate saturation, and pH of 7.35.

There was no difference in reintubation, the primary outcome (above).  The rate of reintubation for respiratory failure was nearly identical (15.9% with BiPAP vs. 16.9% with HFNC).  Secondary outcomes were generally similar, although there was a reduced rate of respiratory failure and ICU length of stay in the HFNC group.

There was poor compliance with BiPAP, with 43% of patients in the BiPAP group unable to tolerate it for 24 hours (compared to no compliance problems in the HFNC group).  The median duration of BiPAP use was only 14 hours.  Although this could be considered a study flaw, it seems like a fair description of how BiPAP performs in actual practice.

This study is a nice companion to Hernandez’s study earlier this year on low-risk patients.   Their previous study showed that post-extubation HFNC is beneficial even in low-risk patients (compared to low-flow oxygen).  Combined, these two studies support broad application of post-extubation HFNC.

I've been extubating tenuous patients to HFNC since the 2014 Maggiore study was released.  This is well tolerated, with no observed complications.  My impression is that this allows us to be more aggressive about liberating patients early from the ventilator, while maintaining a reasonably low reintubation rate.

• Post-extubation HFNC appears noninferior to BiPAP among high-risk patients in preventing reintubation.
• Combined with the previous publication by Hernandez et al., this supports post-extubation HFNC among both high-risk and low-risk patients.

Related

• The beginning of post-extubation HFNC: Maggiore 2014
• HFNC for agressive weaning of the hypoxemic patient (8/2015)
• Post-extubation HFNC for low-risk patients: Hernandez-I study 2016 (3/2016)