Aerosol Therapy in Adults Receiving High Flow Nasal Cannula XXXX Therapy.

@entity1 @entity3045 @entity26 @entity649 @entity2133 @entity1576
BACKGROUND: High flow nasal cannula @entity26 therapy (HFT) is increasingly used in intensive and emergency care departments. @entity1 suffering from @entity1576 , who are likely to benefit from HFT, may require aerosolized bronchodilators; therefore, combining nebulization with HFT may be relevant. This study aimed to identify the optimal settings for the implementation of nebulization within an adult HFT circuit. METHODS: We assessed the mass and the particle size distribution of the aerosol emitted from the nasal cannula (inhalable mass) using mesh- and jet-nebulizers placed at various positions in the HFT circuit. Thereafter, the most relevant combination was used to evaluate the mass of @entity3045 delivered downstream of an anatomical model reproducing aerosol deposition and leakage at the nasal and pharyngeal levels (respirable mass). The influence of HFT flow rate (30, 45, and 60   L/min), of breathing pattern (quiet and @entity649 pattern) as well as of opened and @entity2133 breathing was assessed. RESULTS: The most efficient position was that of a nebulizer placed upstream from the humidification chamber (inhalable mass ranging from 26% to 32% of the nebulizer charge). Using a mesh nebulizer, we observed a respirable mass ranging from 2% to 10% of the nebulizer charge. Higher HFT flow rates and @entity2133 breathing were associated with a lower efficiency. Simulating @entity649 (i.e., increasing the simulated @entity1 inspiratory flow) did not hamper drug delivery as compared to a quiet breathing pattern. CONCLUSIONS: Placing nebulizers within a HFT circuit upstream from the humidification chamber may enable to deliver clinically relevant masses of aerosol at the cannula outlet, but more importantly downstream of the nose and pharynx, even in case of high @entity1 ' inspiratory flow. This method of aerosol therapy is expected to produce a bronchodilatatory effect to be evaluated in the clinical settings.
