Inhaled medication for asthma management: evaluation of how asthma patients, medical students, and doctors use the different devices

Abstract

Asthma results from a combination of three essential features: airflow obstruction, hyperresponsiveness of airways to endogenous or exogenous stimuli and inflammation. Inadequacy of the techniques to use different inhalation devices is one of the causes of therapeutic failure. The main purpose of this study was to evaluate how 20 medical students, 36 resident physicians of Internal Medicine/Pediatrics, and 40 asthma patients used three devices for inhalation therapy containing placebo. All patients were followed at the Pulmonary Outpatient Service of Botucatu Medical School and had been using inhaled medication for at least six months. The following devices were evaluated: metered dose inhalers (MDI), dry powder inhalers (DPI), and MDI attached to a spacer device. A single observer applied a protocol containing the main steps necessary to obtain a good inhaler technique to follow and grade the use of different devices. Health care professionals tested all three devices and patients tested only the device being used on their management. MDI was the device best known by doctors and patients. MDI use was associated with errors related to the coordination between inspiration and device activation. Failure to exhale completely before inhalation of the powder was the most frequent error observed with DPI use. In summary, patients did not receive precise instruction on how to use inhaled medication and health care professionals were not well prepared to adequately teach their patients.