INTRODUCTION Despite the widespread oxygen-culture as more is better in prehospital and hospital-settings, the use of titrated oxygen-flow within a high-flow system can be beneficial especially when combined with aerosol-delivery and also save the patient from unnecessary-hyperoxia. METHODS Forty-five COPD patients were included in this study where they allocated in three-groups (nasal-delivery, oral-delivery, and oronasal-delivery groups) All patients were received their inhaled-salbutamol dose using Aerogon Solo nebulizer by one of three interfaces e.g. nasal-cannula, mouthpiece, and facemask in two conditions; with oxygen-flow and without any oxygen-flow. Pulmonary and systemic salbutamol deposition was estimated through collecting two urine-samples from the patient; 30min post-inhalation and cumulatively 24h post-inhalation. The quantity of salbutamol in these collected samples was measured by high-performance liquid chromatography. Lung function measurement was performed pre-bronchodilator inhalation and 30 min post-bronchodilator to estimate the change in pulmonary functions post-inhalation regarding all tested interfaces. RESULTS COPD patients showed the highest salbutamol percentage excreted 30 min post-inhalation of 5.7% (1.4) with mouthpiece interface when combined with oxygen at p<0.002. While with the same condition using oxygen, valved-facemask showed the highest salbutamol percentage excreted in 24 h post inhalation samples but the difference is only significantly compared to nasal cannula (p<0.006).On the other hand without oxygen delivery, mouthpiece and valved facemask showed approximately the same salbutamol percentage excreted in 30 min post-inhalation samples, higher than that delivered by nasal cannula (p<0.001). Of note, salbutamol delivery is significantly increased with oxygen flow for all interfaces (p<0.05) except with nasal cannula. CONCLUSIONS The nasal cannula is a more comfortable and tolerable interface despite the lower fraction of the delivered drug compared to other tested interfaces. The use of oxygen-flow with aerosol delivery within a high flow system positively affects the delivered drug fraction and the pulmonary deposition of the drug.
The impact of changing patient interfaces on delivering aerosol with titrated oxygen in the high flow system.