[Measurement of inspiratory flow for the selection of the inhalation treatment device for asthma and COPD].

AIM

To assess the proportion of patients with asthma or chronic obstructive pulmonary disease (COPD) with significant bronchoobstruction who do not have inspiratory flows necessary for the adequate use of dry powder inhaler (DPI) devices Diskus and Turbuhaler.

PATIENTS AND METHODS

multicentre cross-sectional study that included 400 patients with asthma or COPD (with FEV1 < 60%) aged 5-91 years tested during exacerbation or usual control visit. All patients underwent lung function testing and measurement of inspiratory flows using In-check Dial.

RESULTS

Significantly lower proportion of patients didn't have inspiratory flows necessary for the regular adequate use of Diskus than for Turbuhaler (21.0% vs 87.0%, chi2 = 350.72, p < 0.0001). In patients tested during exacerbation these proportions were marginally greater. Regression analysis showed a weak association of inspiratory flows measured with different resistance settings with parameters of lung function (best association was seen between resistance setting for Diskus and PEF [%], r2 = 0.104).

CONCLUSIONS

Significant proportion of patients with asthma or COPD with significant bronchoobstruction do not exhibit satisfactory inspiratory flows for the use of dry powder inhaler (DPI) devices (Diskus < Turbuhaler). Spirometry is not to be used for selection of the device for drug application and In-check Dial should be used instead.