@article {Wenzelp837, author = {Markus Wenzel and Dominic Dellweg and Ekkehard H{\"o}hn and Olaf Bourgund and Peter Haidl}, title = {Airway humidity during oxygen therapy: Impact of humidification and applicator design}, volume = {38}, number = {Suppl 55}, elocation-id = {p837}, year = {2011}, publisher = {European Respiratory Society}, abstract = {Background: Stationary oxygen therapy is usually combined with a humidification device in order to prevent mucosal dryness. The impact of the applicator design on airway humidity however has not been investigated to date.Rationale: To investigate the impact of oxygen applicator design on airway humidity.Method: First we developed a sampling and analysis system with a heated sampling probe to measure humidity of air samples under standard conditions during the inspiratory cycle.We measured 12 individuals with an intranasal (standard nasal cannula) and prenasal (Oxynasor) applicator at different flow rates with and without humidification devices. The Oxynasor device is characterized by a cyclone effect of the emitting gas which reduces the oxygen velocity at the outlet.Results: Intranasal humidity dropped significantly from 40.3{\textpm}8.7\% to 29.0{\textpm}6.8\% at a flow rate of three litres when oxygen was given intranasally without humidification (p\<0.01). We observed no significant change in airway humidity when oxygen was given prenasally with and without humidification.Conclusion: We propose two mechanisms to be responsible for this phenomenon: First prenasal application with low outlet velocity of dry oxygen allows for absorption of humidity from the surrounding air prior to nasal entry and second intranasal application with a high exit velocity from the applicator system might dry out the nasal mucosa by means of convection. Prenasal oxygen application with the Oxynasor device might obviate the need for humidification and therefore might simplify application and reduce therapy cost.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/38/Suppl_55/p837}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }