Measurement of Inspiratory Flow Through Three Different Dry Powder Inhalation Devices Using In-Check TM in Children with Asthma

Abstract

Inspiratory flow, generated by the patient through a dry powder inhalation device, determines particle size and dose delivered to the lungs. Children may have difficulty in generating the appropriate inspiratory flow to use these devices effectively. The aim is to evaluate inspiratory flow of children with asthma inhaling through In-Check^TM (Clement Clark International, Edinburgh Way, UK), equipped with adapters simulating resistance of three devices and to relate it to spirometric values and age.

Forced spirometric parameters and inspiratory flow values through In-Check^TM were evaluated in stable children with asthma, aged 6 to 16 years. The inhalation devices tested were: Aerolizer^TM (Novartis, East Hanover, NJ), Turbuhaler^TM (Astra Zeneca, Lund, Sweden), and Diskus^TM (GlaxoSmithKline, Research Triangle Park, NC). Inspiratory flow through all devices exceeded 60 L/min in all but 1 child. More than half of the children (16/30) were able to generate a flow 120 L/min or more through Aerolizer^TM, 8 of 30 through Diskus^TM, and 1 of 30 through Turbuhaler^TM. For the Turbuhaler^TM, inspiratory flows were significantly positively correlated with age. Inspiratory flows were significantly correlated with peak inspiratory flow (PIF) for all the devices. More children were able to obtain higher inspiratory flows through Aerolizer^TM. In-Check^TM is a valuable instrument to evaluate the inspiratory flow a child can generate through a dry powder inhalation device. (Pediatr Asthma Allergy Immunol 2006; 19[1]:6–13.)