Avaliação da capacidade funcional de crianças e adolescentes com asma grave utilizando o teste de caminhada de 6 minutos e o teste de exercício cardiopulmonar

Abstract

Introduction: Limited physical activities is a common cause of failure in disease control in children and adolescents diagnosed with severe asthma. There are several causes of limitation, as: asthma itself, physical deconditioning and exercise induced bronchoconstriction (EIB). Therefore, research is needed to investigate the cause of physical limitation in this population, in order to carry out a targeted therapeutic approach capable of improve quality of life. Objective: Evaluate the complaint of physical activities limitation in children and adolescents with severe asthma by comparing the distances walked in the 6 minute walk test (6MWT), and evaluate the impact of deconditioning and EIB, previously identified by cardiopulmonary exercise test (CPET), in the functional capacity of these patients. Methods: Cross sectional study, between 2018 and 2020, with children aged 7 18 years. Severe asthmatics were included (described as patient using doses ≥ 800 μg equivalent budesonide, with adherence rate ≥ 80%, adequate inhalation technique and medicated comorbidities AG), which presented only limitation to physical exercise as failure to asthma control. They were paired with healthy controls (control group CG) by sex, age and body mass index. AG and CG performed a cardiopulmonary exercise test on a cycle ergometer, according to international recommendations, and a 6 minute walk test according to the recommendations of the American Thoracic Society (ATS). Exercise induced bronchoconstriction (EIB) was defined as a reduction of ≥ 10% in FEV1 in the end of the CPET and the 6MWT. Additionally, the following were evaluated: difference in the distance walked between the groups and impact of deconditioning (measured by VO2 in CPET) and physical inactivity (measured by questionnaire), in the distance walked in the 6MWT. Results: The prevalence of EIB in asthmatics was 60% vs 30% in the control group. Deconditioning was found in 60% of asthmatics and in 57% of controls. Physical inactivity was reported in 100% of asthmatics and in 37% of controls. The 6MWT showed 33.33% sensitivity, 43.62% accuracy and 87.5% specificity in the diagnosis of EIB when compared to TECP. Asthmatic patients walked shorter distances than controls, and these distances were shorter when associated with EIB and, mainly, with deconditioning. Results: The prevalence of EIB in asthmatics was 60% and in the control group, 30%. Deconditioning was found in 60% of asthmatics and in 57% of controls. Physical inactivity was 100% for asthmatics and 37% for controls. Asthmatic patients traveled shorter distances than the controls, these distances becoming shorter and shorter when associated with EIB and, mainly, with deconditioning. Conclusion: The study results suggest that the reduction in the distance walked in the 6MWT is multifactorial, and not only as consequence of asthma, signaling that the disease control, conditioning and physical activity improvement may play a crucial role in quality of life in this population.