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We know that high flow nasal cannula is an option in the management of acute hypoxic respiratory failure without hypercapnea. A newer iteration of high flow, "high velocity nasal insufflation" (HVNI), may be up-and-coming.
According to its makers (Vapotherm), it is reported to work mainly by using smaller bore nasal cannulae that deliver the same flows at higher velocities, thereby more rapidly and repeatedly clearing dead space, facilitating gas exchange and potentially offering ventilatory support.
In an industry-sponsored non-inferiority study published earlier this year:
- 204 adult patients in 5 EDs
- Any acute respiratory failure deemed by the treating physician to require non-invasive positive pressure ventilation (NPPV)
- Patients randomized to either NPPV (bilevel positive airway pressure) or HVNI
- Rate of HVNI treatment failure (26%) and intubation @ 72 hours (7%) fell within predefined noninferiority margins
- Rates of PCO2 clearance were similar between HVNI and NPPV groups
- The study was not powered to detect differences between different etiologies for respiratory failure
- Authors concluded that HVNI is noninferior to NPPV for all-comer respiratory failure.
Bottom Line:
The availability of a nasal cannula that helps with CO2 clearance would be great, and an option for patients who can't tolerate the face-mask of NPPV would be even better.
HVNI requires more investigation with better studies and external validation before it can really be considered noninferior to NPPV, but it certainly is interesting.
References
- https://vapotherm.com/high-velocity-nasal-insufflation/
- Doshi P, Whittle JS, Bublewicz M, et al. High-Velocity Nasal Insufflation in the Treatment of Respiratory Failure: A Randomized Clinical Trial. Ann Emerg Med. 2018;72(1):73-85.