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Updated: Aug 23, 2026

Modeling and Simulations of Olfactory Drug Delivery with Passive and Active Controls of Nasally Inhaled Pharmaceutical Aerosols
Published on: May 20, 2016
An evaluation of 2 new devices for nasal high-flow gas therapy
Jonathan B Waugh1, Wesley M Granger
1Respiratory Therapy Program, Critical Care Sciences Department, University of Alabama at Birmingham, 1705 University Blvd, RMSB 480, Birmingham AL 35294-1212, USA. waughj@gmail.com.
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.
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