Dynamic hyperinflation impairs daily life activity in asthma

Introduction Dynamic hyperinflation has been documented in asthma, yet its impact on overall health and daily life activities is unclear. We assessed the prevalence of dynamic hyperinflation in moderate to severe asthma and its relationship with the scores of a set of specific and general respiratory health questionnaires. Methods 77 non-smoking asthma patients (GINA step 4–5) were consecutively recruited and completed 5 questionnaires: Asthma Control Questionnaire, Clinical COPD Questionnaire, St. George9s Respiratory Questionnaire, London Chest Activity of Daily Living scale (LCADL), Shortness of Breath with Daily Activities (SOBDA). Dynamic hyperinflation was defined as ≥10% reduction in inspiratory capacity induced by standardised metronome-paced tachypnea. Associations between level of dynamic hyperinflation and questionnaire scores were assessed and adjusted for asthma severity. Results 81 percent (95 CI: 71.7–89.4%) of patients showed dynamic hyperinflation. Higher levels of dynamic hyperinflation were related to poorer scores on all questionnaires (r=0.228–0.385, p Conclusion Dynamic hyperinflation is associated with poorer overall health and impaired daily life activities, independent of asthma severity. Because of its major impact on everyday life activities, dynamic hyperinflation is an important target for treatment in asthma.