Concurrent Use of Metered-Dose and Dry Powder Inhalers by Children with Persistent Asthma Does Not Adversely Affect Spacer/Inhaler Technique

Abstract

Background: Studies conducted in adults have suggested that patients who use a metered-dose inhaler/holding chamber spacer (MDI/S) and dry powder inhaler (DPI) concurrently will have poorer MDI/S technique than that of patients who use MDI/S exclusively. To our knowledge, as of August 31, 2006, no studies have been performed in pediatric patients. Objective: To compare MDI/S technique scores of children using only MDI/S with scores of those using both MDI/S and DPIs. Methods: The MDI/S technique of children aged 6–17 years, with persistent asthma, recruited from a general pediatric practice population for an asthma intervention study project was scored using a standardized checklist. MDI/S scores of children who were being treated with maintenance and rescue medication delivered only by MDI/S were compared with those treated with both MDI/S (rescue) and DPI (maintenance). Scores lower than 70% were considered to be inadequate. Results: A total of 117 patients (73 male, 44 female), aged 9.70 ± 3.1 years (mean ± SD), with persistent asthma, participated in the study. There were 83 children (54 male, 29 female, age 9.4 ± 3.2 y) in the MDI/S only group and 34 (19 male, 15 female, age 10.3 ± 2.9 y) in the MDI/S + DPI group. In the MDI/S + DPI group, Diskus was the DPI used for 32 patients, and Turbuhaler was used by 2 children. Sixteen patients had severe persistent asthma, 80 had moderate persistent asthma, and 21 had mild persistent asthma as classified by National Heart Lung and Blood Institute guidelines. No difference in sex and age demographics existed; however, there was a difference in the distribution of asthma severity between groups (ie, no patients with mild persistent asthma in the MDI/S + DPI group; p ≤ 0.01). Mean score for the MDI/S only group was 86 ± 17% and, for the MDI/S + DPI group, 90.1 ± 12% (p = 0.15). More patients in the MDI/S group had inadequate scores (18%) compared with those in the MDI/S + DPI group (3%; p < 0.05). Conclusions: While DPI and MDI/S techniques are markedly different in several significant ways, concurrent use of these inhalers did not adversely affect MDI/S technique scores of pediatric patients with persistent asthma, compared with those using MDI/S alone. Patients in the MDI/S only group had an inadequate MDI/S score (<70%) more often than did patients in the MDI/S + DPI group.