Abstract
Peak inspiratory flow (PIF 1/min) was measured to assess PIF value of four inhalers: Aeroliser, Diskus, EasiBreathe and Turbuhaler. The PIF meter (In-Check Dial, Clement Clark, U.K.) was used.
There were performed four successive measurements by means of cross over method. PIF was evaluated from the points of view: diagnosis, severity of bronchial obstruction, sex, age and smoking habit.
The study of four centers involved 502 subjects, 255 men, 247 women, average age 58.6 of years (men 60.8 women 56.4), chronic obstructive lung disease (COPD) 284, bronchial asthma 218. PIF values (L/min) of individual inhalers were: Easi-Breathe 110.9 (+-39), Aeroliser 99.8 (+-35), Diskus 87.8 (+-31), Turbuhaler 66.3 (+-24), respectively.
All relaUonships of PIF among in halers were significantly different (ANOVA P < 0.001). PIF was decreased significantly with age, mostly after 55 of years.
Significantly higher values of PIF (P < 0.01) were in men compared to women in all inhalers. Average PIF of inhalers was significantly lower in COPD compared to asthma (P < 0.01-0.001) and surprisingly lower (P < 0.05) in non-smokers compared to smokers as well.
Mild asthma had higher PIF compared to severe asthma (P < 0.001) but severity of COPD had no effect on PIF values. Optimal values of PIF were in Easi-Breathe inhaler because there were no values under 30 1/min.
Three other inhalers had PIF under 30 1/min: Aeroliser in 1 %, Diskus in 2.8 % and Turbuhaler in 7.8 % of patients. In all 502 COPD or asthma subjects the studied inhalers were able to generate sufficient PIF in a great majority subjects with bronchial obstruction.