Question: Is high-flow nasal cannula non-inferior to non-invasive ventilation (NIV) in reducing rates of reintubation and postextubation respiratory failure in high risk patients?
Study Type: Multicenter, randomized, non-inferiority trial in 3 ICUs in Spain
Study Population: Patients receiving mechanical ventilation > 12 hours were eligible for the trial if they met at least one of the following criteria: age >65, CHF as primary indication for MV, mod-severe COPD, APACHE II >12 on day of extubation, BMI >30, airway patency problems, inability to deal with respiratory secretions, difficult weaning, 2 or more co-morbidities, or MV > 7 days. Exclusions included DNR, tracheostomies, and self-extubations.
Study Groups: Patients in the HFNC arm were placed on HFNC with flow set at 10L/min which was titrated up at 5L/min intervals until pts experienced discomfort. FIO2 was titrated to keep SpO2 > 92%. Patients in the NIV arm had PEEP and IPAP adjusted to targets of RR 25, SaO2 92, and pH 7.35. FiO2 was titrated to an SpO2 of at least 92%. Both groups were switched to conventional O2 after 24 hrs.
Primary Outcomes: Reintubation and postextubation respiratory failure within 72 hrs. Non-inferiority margin set at 10%
Results: 604 patients were randomized. Notable patient characteristics: respiratory failure as primary diagnosis (56%), surgical patients (38%), neurology patients (3%), median # of high risk factors (3). HNFC was non-inferior to NIV (19.1% of pts required reintubation in NIV group vs 22.8% in HFNC group). More patients in the NIV group experienced postextubation respiratory failure (26.9% HFNC vs 39.8% NIV). Close to 50% of NIV patients were unable to tolerate therapy for the full 24 hours (median duration 14 hrs). Other than a small reduction in ICU LOS with HFNC, secondary outcomes were similar between the two groups.
Caveats: Both HFNC and NIV were given for only 24hrs (in contrast to some other studies with longer periods of therapy), sedatives to facilitate NIV tolerance were not allowed, trial was not blinded.
Take-home Point: In high risk patients, HFNC appears non inferior to NIV in reducing rates of reintubation and postextubation respiratory failure.