INTERRUPTER TECHNIQUE

Merkus, PJFM., Stocks, J., Beydon, N., Lombardi, E., Jones, M., McKenzie, SA., Kivastik, J., Arets, B., Stanojevic, S. 2010. Reference Ranges for Interrupter Resistance Technique: The Asthma UK Initiative. European Respiratory Journal. 36:157-163

RATIONALE:

Measuring interrupter resistance (Rint) is an increasingly popular lung function technique and especially suitable for preschool children because it is simple, quick and requires only passive cooperation. An ERS/ATS task force recently published empirical recommendations related to procedures, limitations and interpretation of the technique. However, for valid interpretation, high quality reference equations are required and these have been lacking.

OBJECTIVES:

To collate Rint data from healthy children to produce more robust reference equations and to examine the influence of methodological differences on predicted Rint values

METHODS:

Rint data from healthy children were collected from published and unpublished sources. Reference equations for expiratory and inspiratory Rint were developed using the LMS method.

RESULTS:

Data from 1090 children aged 3-13 years (51% boys) were collated to construct sex-specific reference equations for expiratory Rint and 629 (51% boys) children for inspiratory Rint. Height was the best and only independent predictor of both expiratory and inspiratory Rint. Differences between centres were clinically irrelevant, and differences between ethnic groups could not be examined.

CONCLUSIONS: