Clinimetric properties of breath‐stacking technique for assessment of inspiratory capacity

Abstract

Breath stacking (BS) is used as an alternative method for lung expansion therapy and the assessment of inspiratory capacity in uncooperative patients. The aims of the present study were to identify the reproducibility of the BS technique in healthy volunteers and to compare BS with conventional spirometry with regard to inspiratory capacity. A cross-sectional study was carried out. Eighty-five healthy volunteers (21.78 ± 2.79 years; 41 men, 44 women) underwent spirometry and BS. Lung function, anthropometric and cardiopulmonary parameters were evaluated prior to the intervention. BS was performed with a unidirectional inspiratory valve by two different examiners. The order of each examiner was randomized. Spirometric tests were performed three times, and the BS manoeuvre was evaluated three times by each examiner. Respiratory rate, heart rate and peripheral arterial oxygen saturation were determined before, during and following the manoeuvre. There were no statistically significant differences in the intra-examiner and inter-examiner analyses for the volume mobilized during BS, respiratory rate, duration of BS manoeuvre or perceived effort index (p > 0.05). The intra-class correlation coefficient was greater than 0.7 for all variables analysed. Maximal volumes achieved using the BS technique were significantly higher than those achieved with conventional spirometry (p < 0.0001). Data from both the intra-examiner and inter-examiner analyses suggest that the BS technique is reproducible. This technique mobilizes greater lung volumes than conventional spirometry.