| Abstrakt: |
Background: Delivery of inhaled medication for the treatment of bronchoconstrictive disease in the ED is complicated by the loss of some of the inhaled dose to the upper airway. This laboratory-based study mimicking adult use sought to evaluate the magnitude of such losses from different nebulizer types in relation to delivery to the lungs using a new anatomic upper airway model. Methods: Three different nebulizers (n=9 replicates/device type) were evaluated with albuterol sulfate solution (2.5 mg/3 ml). Nebulizer types included Solo*/ Ultra* vibrating mesh with Pro-X Controller, Aerogen Ltd. Ireland; Nebutech* HDN* continuous jet (Salter Labs, Arvin, CA), operated with 50 psig compressed air at 7 L/min; AeroEclipse*-Il breath actuated (Monaghan Medical Corp., Plattsburgh, NY) operated with compressed air under similar conditions. The neb mouthpiece was attached to the mouth opening of the Aerosol Delivery to Anatomic Model (ADAM-III) adult upper airway model (Trudell Medical International, London, Canada), where a filter was located at the airway outlet, representing the carina. The filter was connected to a breathing simulator (ASL 5000, IngMar Medical, Pittsburgh, PA) simulating tidal breathing (Vt = 600 mL; 10 cycles/min; inspiratory: expiratory ratio 1:2). 5 breathing cycles were undertaken, following which the model was disconnected from the test apparatus and the mass of albuterol deposited in the model airway (O-P) and on the filter (CARINA) assayed by HPLC-UV spectrophotometry. Results: The table contains measurements of total mass albuterol (mg; mean ± SD) recovered from the model. All nebulizer types generated droplets that were large enough to deposit in the model oropharynx and would therefore be unavailable for delivery to the lungs. More importantly, there were differences between nebulizer types and the mass of medication that penetrated as far as the 'carina', with the breath-actuated nebulizer delivering significantly more albuterol than the other two devices (1-way ANOVA, p < 0.001). Conclusions: Nebulizer type is a consideration for the delivery of rescue medication where the goal is to deliver as much drug to the constricted airways rapidly. This in vitro study indicated that the breath-actuated nebulizer has the potential for optimizing medication delivery, but clinical studies would be required to confirm this finding. Disclosure: J Schloss participates in Monaghan Medical's (MMC) Speaker Bureau. J Mitchell is a consultant to MMC. [ABSTRACT FROM AUTHOR] |
