Analysis of Tidal Breathing in Healthy Japanese Children for Optimized Nebulizer Dosing

抄録

Background and Objective: Lung function parameters are used to evaluate drug delivery by nebulization. The uniform breathing profiles indicated for adults and pediatrics are shown in The United States Pharmacopeia. However, lung capacity generally increases in proportion to the physical development and few reports describe reference values for Japanese children. The aim of this study was to establish normal reference values for tidal breathing in healthy Japanese children, to provide appropriate settings for evaluation of drug delivery by nebulization.

Methods: Tidal breath loops and lung function parameters were obtained from 65 healthy children (26 males and 39 females) aged 1-12 years using a flow analyser system. Regression analysis was performed to evaluate the relationship between the subjects' demographics and the following parameters: tidal volume, respiratory rate, and minute ventilation.

Results: There was significant correlation between these parameters and the subject age, and normal reference values were established for tidal volume in healthy Japanese children of various ages; these correlated well with age. No difference was found in tidal volume with respect to positioning (sitting or supine) or sex.

Conclusions: With reference to these data, we created equations that predict the tidal volume, as a guide in establishing appropriate settings for nebulization. These parameters can be applied to the in vitro breath simulator to evaluate the drug delivery rate and total amount of drug delivered by nebulization to support selection of appropriate dose regimens for nebulized inhalation.