Spacer inhalation technique and deposition of extrafine aerosol in asthmatic children

¹ UWA School of Paediatrics and Child Health, Princess Margaret Hospital for Children, GPO D184, Perth. Western Australia. 6840: Fax: +61 8 9388 2097 E-mail: christinar@ichr.uwa.edu.au
² Dept of Nuclear Medicine, Princess Margaret Hospital for Children, Perth. Western Australia. 6840
³ Lovelace Respiratory Research Institute, Albuquerque, NM USA

^* To whom correspondence should be addressed. E-mail: christinar{at}ichr.uwa.edu.au.

	Abstract

The aim of this study was to measure airway, oropharyngeal and gastrointestinal deposition of ^99mTc labelled HFA-BDP, after inhalation via pMDI-spacer (Aerochamber Plus^TM) in asthmatic children.

A total of 24 children (aged 5-17 yrs) with mild asthma inhaled the labelled drug. 12 children took 5 tidal breaths after each actuation (tidal). 12 children used a slow maximal inhalation followed by a 5-10 s breath hold (breath hold). Simultaneous anterior and posterior planar gamma scintigraphic scans (120 s acquisition) were recorded.

For the "tidal" group, mean (SD) lung deposition (%ex-actuator, attenuation corrected) was 35.4 (18.3)%, 47.5 (13.0)% and 54.9 (11.2)% in patients aged 5-7 (n=4), 8-10 (n=4) and 11-17 (n=4) years. Oropharyngeal and gastrointestinal deposition was 24.0 (10.5)%, 10.3 (4.4)% and 10.1 (6.2)%. With the "breath hold" technique, lung deposition was 58.1 (6.7)%, 56.6 (5.2)% and 58.4 (9.2)%. Oropharyngeal and gastrointestinal deposition was 12.9 (3.2)%, 20.1 (9.5)% and 20.8 (8.8)%.

Inhalation of the extrafine formulation with the "breath hold" technique showed significantly improved lung deposition compared with "tidal" breathing across all ages. Oropharyngeal and gastrointestinal deposition was markedly decreased, regardless of which inhalation technique was applied, compared with a previous paediatric study using the same formulation delivered via a breath-actuated MDI.