Guidelines suggest that pressurized metered dose inhalers (pMDI) plus spacers are the delivery system of choice for children. However, they are bulky, which makes them inconvenient. It was suggested that the smaller dry-powder inhalers (DPIs) may be suitable for delivering short-acting bronchodilators to preschool children. This study considered whether preschool children could reliably generate sufficient inspiratory flows to use the Clickhaler DPI. Twenty-seven asthmatic and 34 nonasthmatic children, aged 2-5 years, were recruited. Following training, they were asked to inhale four times through a Clickhaler flow monitoring system, twice "steadily" and twice "forcefully." Inspiratory flow data were collected during each inhalation. Of the 3-, 4-, and 5-year-old asthmatics, 62.5, 100, and 100%, respectively, could reliably differentiate between inhaling and exhaling through the DPI. For nonasthmatics, the figures were 66, 60, and 88%, respectively. All but one of the children who understood the instructions generated a PIF of greater than 15 l/min (range, 13.9-88.3 l/min and 21.2-84.5 l/min in asthmatic and nonasthmatic children, respectively). These data indicate that the majority of children aged 3 years and above could reliably inhale rather than exhale through a dry-powder inhaler, and that they generate inspiratory flows sufficient to use the Clickhaler effectively. The results indicate that the device could be a suitable delivery system for beta(2)-agonists in preschool children.
Copyright 2003 Wiley-Liss, Inc.