Mishandling of pMDI and DPI inhalers in asthma and COPD - Repetitive and non-repetitive errors

Background: Pharmacological treatment of asthma and chronic obstructive pulmonary disease (COPD) is based mainly on inhaled medications. There is a continuous need to examine and train patients in their inhalation technique. The objective of the presented study is to determine whether the errors which patients made during inhalations are repetitive, and therefore easier to eradicate, or rather accidental, hence require more attention and effort from the health care professionals. Methods: It was a prospective, cohort study which included adults with asthma or COPD, who have used at least one inhaler daily on a regular basis. Inhalation technique was evaluated twice in a six months interval basing on a list of the most common errors in the inhalation technique. There was no training of inhalation skills between visits. Results: There were 92 patients (46 asthmatics, 46 with COPD; median age 66 years, median duration of the disease 10 years) included into the analysis. 92% of patients made at least one error during their inhalation. Among pMDI users the most common device mishandlings were: no or too short breath-holding after inhalation (60% of the patients during the first visit; 50% during the 2nd), too rapid and too forceful inhalation (52%; 61%) and lack of exhalation before the use of the medicine (48%; 43%). Among the DPI users, the most numerous errors were: no or too short (less than 3 s) breath-holding after inhalation (62%; 55%) and slow and not forceful enough inhalation (38%; 36%). When comparing the mishandlings in the inhalation technique conducted during the first and second visit the majority of the errors conducted by the patients were repetitive. However, some errors such as too early termination of inhalation (p = 0.016), inhalation through the nose during actuation (p = 0.002) among pMDI users and lack of expiration before inhalation (p = 0.027) among DPI users, were non-permanent. Conclusions: Improper inhalation technique is very common and the majority of errors made in inhalation technique are repetitive. This emphasizes the role of an ongoing verification and training of a proper inhalation technique in all patients that are regularly treated with inhalers.