The potential benefit of continuous metered-dose inhaler inhalation technique verbal counselling on asthmatic

Subjects' improper usage of their metered-dose inhalers (MDI) is considered a chief cause of poor asthma control. The work presented here aims to evaluate the effect of MDI verbal counselling on subjects' lung function and inhalation technique.

A total number of 900 asthmatic subjects (450 female) were gathered from University hospital outpatient clinics from January 2017 to May 2019 with a mean (SD) age 45.2 (17.1) years old. They were divided into two groups. The first was monthly asthma follow-up, for three visits, (450 (266 females) subjects). The other group was monthly asthma follow-up, for three visits plus MDI inhalation technique verbal counselling (450 (184 female) subjects). At the beginning of studying group 2 and at every monthly visit (three visits), each subject was asked to show the investigator his MDI inhalation technique and the number of mistakes was noticed and adjusted. Additionally, at each visit, their forced expiratory volume in one second (FEV₁ ) as a percentage of the forced vital capacity (FVC) and peak expiratory flow (PEF) were measured.

No subject dropped out from group 2; however, 95 subjects dropped out from group 1 with no improvement in the lung function tests. The mean number of accurate steps of the MDI inhalation technique observed in group 2 was improved significantly (P < .001) as the number of visits increased particularly in children. "Start to inhale slowly, through the mouth and at the same time press the canister to actuate a dose and maintain a slow and deep inhalation, through the mouth, until the lungs are full of air (This should take an adult 4-5 seconds)" was the common repetitive mistake. There was a significant improvement (P < .05) in the lung function test scores after the counselling in group 2, especially in old subjects.

MDI's counselling must be continually offered to the asthmatic subject at any possible chance to improve and sustain the optimal MDI inhalation technique and probably improve subjects' lung function score.