Background: The traditional nasal cannula with bubble humidifier is limited to a maximum flow of 6 L/min to minimize the risk of complications. We conducted a bench study of 2 new Food and Drug Administration-approved nasal cannula/humidifier products designed to deliver at flows> 6 L/min.
Methods: Using a digital psychrometer we measured the relative humidity and temperature of delivered gas from each device, at 5 L/min increments over the specified functional high-flow range.
Results: The Salter Labs unit achieved 72.5-78.7% relative humidity (5-15 L/min range) at ambient temperature (21-23 degrees C). The Vapotherm device achieved 99.9% relative humidity at a temperature setting of 37 degrees C (5-40 L/min).
Conclusions: Both devices meet minimum humidification standards and offer practical new treatment options. The patient-selection criteria are primarily the severity of the patient's condition and cost.