Dynamic hyperinflation in patients with asthma and exercise-induced bronchoconstriction

Publication date: Available online 14 February 2017
Source:Annals of Allergy, Asthma & Immunology
Author(s): Olga Mediano, Raquel Casitas, Carlos Villasante, Elisabet Martínez-Cerón, Raúl Galera, Ester Zamarrón, Francisco García-Río
BackgroundLittle is known about the behavior of operative lung volumes during exercise in patients with asthma and exercise-induced bronchoconstriction (EIB).ObjectivesTo compare the presence of dynamic hyperinflation (DH) in patients with mild asthma with and without EIB and in healthy individuals and to relate the changes in end-expiratory lung volume (EELV) with postexercise airflow reduction.MethodsA total of 122 consecutive stable patients (>12 years of age) with mild asthma and 38 controls were studied. Baseline lung volumes were measured, and all patients performed an exercise bronchial challenge. At each minute of exercise, EELV and end-inspiratory lung volume (EILV) were estimated from inspiratory capacity measurements to align the tidal breathing flow-volume loops to within the maximal expiratory curve.ResultsDH was more frequent in patients with asthma and EIB (76%) than in patients with asthma but without EIB (11%) or controls (18%). The EELV increased in patients with asthma and EIB and decreased in patients with asthma without EIB and controls during exercise. In the patients with asthma, the decrease in forced expiratory volume in 1 second after the exercise challenge correlated with age (r = −0.179, P = .05), baseline forced vital capacity (r = 0.255, P = .005), EELV increase (r = 0.447, P < .001), and EILV increase (r = 0.246, P = .007). Age, baseline forced vital capacity, and magnitude of DH were retained as independent predictors of EIB intensity.ConclusionIn patients with asthma and EIB, the development of DH is very frequent and related to the intensity of postexercise bronchoconstriction. This finding could implicate DH in the development of EIB.



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