Written by Clay Smith
High flow nasal cannula (HFNC) did not reduce 28-mortality in immunocompromised patients with acute hypoxemic respiratory failure (AHRF) compared to standard oxygen therapy.
Why does this matter?
HFNC has been shown to reduce 90-day mortality in patients with AHRF in the FLORALI trial. However, immunocompromised patients did not seem to benefit on subgroup analysis. In another RCT, immunocompromised patients had no benefit with non-invasive ventilation (NIV) compared to standard oxygen. This was a focused look to see if HFNC would help immunocompromised patients.
HIGH flow no go
HIGH was a RCT with 778 immunocompromised patients with AHRF on at least 6L/min NC oxygen. They received either standard oxygen therapy or HFNC. They did not include patients with HIV/AIDS. There was no difference in 28-day mortality: HFNC 138 (35.6%) vs standard oxygen 140 (36.1%), difference −0.5 (95%CI, −7.3 to 6.3). There was also no difference in outcome for any subgroup for either mortality or need for intubation. One concern is that though they had a minimum SpO2 target of ≥95%, they did not set a maximum target, which could have muted some of the potential beneficial effect of HFNC, as we know hyperoxia increases mortality.
How does this change my practice? In patients similar to those in this study, I now know that HFNC (and NIV from prior study) doesn’t reduce mortality. This study doesn’t preclude use of HFNC, but it does help us recognize its limitations.
Don’t miss this amazing post by Josh Farkas on PulmCrit (EMCrit).
Effect of High-Flow Nasal Oxygen vs Standard Oxygen on 28-Day Mortality in Immunocompromised Patients With Acute Respiratory Failure: The HIGH Randomized Clinical Trial. JAMA. 2018 Oct 24. doi: 10.1001/jama.2018.14282. [Epub ahead of print]
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