The Effect of Training Inhalation Technique with or without Spacer on Maximum Expiratory Flow Rate and Inhaler Usage Skills in Asthmatic Patients: A Randomized Controlled Trial

Background: The most common treatment for asthma is transferring the drug into the lungs by inhaler devices. Besides, correct use of inhaled medication is required for effectiveness of pharmacotherapy. Thus, it is necessary to train the patients how to use Metered Dose Inhaler (MDI). This study aimed to determine the effect of training about MDI usage with or without spacer on maximum expiratory flow rate and inhaler usage skills in asthmatic patients. Methods: This randomized clinical trial was conducted on 90 asthmatic patients who were randomly divided into inhalation technique group with spacer, inhalation technique group without spacer, and a control group. Then, the Peak Expiratory Flow Rate (PEFR) was measured using a peak flow meter, as a basic test. In addition, the patients’ functional skills of inhalation technique were assessed using two checklists. Afterwards, 3 sessions of training were arranged for both groups. PEFR and the ability to use the MDI were evaluated immediately and 1 month after the intervention. Finally, the data were entered into the SPSS statistical software (v. 18) and analyzed using independent t-test and repeated measures ANOVA. Results: After the intervention, MDI usage skills improved in the two intervention groups compared to the control group (P<0.001). In addition, a significant difference was found between the intervention groups and the control group regarding the mean of PEFR after the intervention (P<0.001). However, no significant difference was observed between the two intervention groups (P=0.556). Conclusion: According to the results, providing appropriate training for asthmatic patients increased MDI usage skills, and both methods of inhalation (with or without spacer) could improve the PEFR among the patients. Trial Registration Number: IRCT2013091514666N1