[The variability of peak inspiratory flow (PIF) on valves imitating dry powder inhalers resistance during asthma and COPD exacerbations].
BACKGROUND
Drugs used in asthma or COPD exacerbation are delivered to the lungs by inhalation. This is facilitated, among other factors, by the use of dry powder inhalers (DPIs). Lung deposition from DPI depends predominantly on peak inspiratory flow (PIF). The aim of the study was to asses the variability of PIF generated by patients using different types of DPI inhalers during asthma or COPD exacerbation and to trace possible relationships between PIF value and some spirometric values.


METHODS
There were 28 patient fulfilling inclusion criteria, among them 17 (4 women) were suffering from COPD and 11 (8 women) from asthma. Spirometry, PEF and PIF measurements were performed in the first and the last day of hospitalisation. Peek inspiratory flow was obtained using In-Check DIAL - a device which simulated airflow resistances equivalent to Turbuhaler, Diskus and Aeroliser respectively.


RESULTS
The significant improvement in PIF was observed only in patients with COPD. There were no statistically significant correlations between PIF and both FEV1 and PEF except those in the first day of hospitalization in COPD patients (r = 0.66-0.81). Optimal PIF was achieved in all patients only with Diskus.


CONCLUSIONS
Measurements of peek inspiratory flow are useful in choosing the most suitable DPI for patients with COPD and asthma exacerbations. We conclude that in those patients, PIF measurement should complement a standard spirometry.
Grabowski
Marcin
M
Katedra i Klinika Chorób Wewnetrznych i Alergologii Akademii Medycznej we Wrocławiu, Wroclaw, Poland.
Barg
Wojciech
W
Chmielowicz
Beata
B
Kopeć
Agnieszka
A
Panaszek
Bernard
B
D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy / Q000503:physiopathology*; D001993:Bronchodilator Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D001239:Inhalation / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D010366:Peak Expiratory Flow Rate; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000503:physiopathology*; D015203:Reproducibility of Results; D013147:Spirometry; D018709:Statistics, Nonparametric
D001993:Bronchodilator Agents