Inspiratory Flowthrough Dry-Powder Inhalers (DPIs) in Asthmatic Children 2 to 12 Years Old

The objective of the study was to measure peak inspiratory flow (PIF) generated through Turbuhaler, Aerolizer, and Diskus inhalers in children 2 to 12 years old. An open-labeled, stratified, randomized, crossover comparison of the 3 dry-powder inhalers (DPIs) in asthmatic children presenting to the Pediatric Pulmonary Clinic, UNM Hospital. Patients were excluded if they had used a DPI previously or were experiencing an asthma exacerbation during their visit. Patients were instructed how to use one device at a time and were asked to demonstrate the use without coaching from the study coordinator or parents. PIF was measured by a pneuomotachograph placed inline with each inhaler and patients completed a questionnaire about their device preference. A total of 60 patients completed at least one part of the study, 10 in each age group. The mean PIF through Aerolizer (55.7 ± 23.7 L/min) was significantly higher than Diskus (48.4 ± 18.9L/min) and Turbuhaler (37.5 ± 14.8 L/min) (p < 0.05 for all the comparisons). The mean PIF through Diskus was significantly higher than Turbuhaler (p < 0.001). The percentage of total patients who could generate a PIF ≥ 30L/min with Aerolizer (96%) was statistically higher than those with Diskus (84%) or Turbuhaler (69%) (p < 0.05). No difference was found in the percentage of patients who generated PIF ≥ 60L/min with different devices. Eighty-seven percent of generated PIF measurements in children younger than 5 years old were less than 60L/min, whereas 85% of generated PIF measurements in children older than 2 years old were at least 30L/min. When asked which device they preferred, a greater percentage overall (41%) chose Diskus. (Pediatr Asthma Allergy Immunol 2006; 19[4]:223–230.)