Measurement of peak inspiratory flow rates with an in-check meter to identify preschool children's ability to use dry powder inhalers; Diskus and Turbuhaler

Abstract Rationale Although current guidelines recommended the pressured metered dose inhaler with a spacer for preschool children with asthma, dry powder inhalers may be a valuable treatment alternative in some cases who do not like a face mask. Methods To identify preschool children's ability to generate enough inspiratory flow, peak inspiratory flow (PIF) rates of 57 healthy children aged 3 to 6 yrs were measured with an In-Check Meter after practicing with an instructor. Two different calibrated resistances were attached to the Meter to mimic the internal resistance of each inhaler; Diskus and Turbuhaler. Results The ability of children to generate adequate inspiratory flow increased with age. The percentages of the 3-, 4-, 5-, 6-year-old children who were able to inhale reliably through the devices were 30% (3/10), 79.0% (15/19), 100% (16/16), and 100% (12/12), and respectively. In these children, 100%, 93.3%, 100%, and 100% achieved the PIF rate enough for Diskus (30 L/min). In contrast, 66.7%, 66.7%, 62.5%, and 91.7% generated the adequate PIF rate for Turbuhaler (60 L/min). Conclusions Thus most of children ≥5 yr could use dry powder inhalers, and Diskus might be more useful for preschool children than Turbuhaler.