ABSTRACT
BACKGROUND: Patients with severe refractory asthma (SRA), even when using high doses of multiple controller medications in a regular and appropriate way, can have persistent complaints of exercise limitation. METHODS: This was a cross-sectional study involving patients with SRA (treated with ≥ 800 µg of budesonide or equivalent, with ≥ 80% adherence, appropriate inhaler technique, and comorbidities treated), who presented no signs of a lack of asthma control other than exercise limitation. We also evaluated healthy controls, matched to the patients for sex, age, and body mass index. All participants underwent cardiopulmonary exercise testing (CPET) on a cycle ergometer, maximum exertion being defined as ≥ 85% of the predicted heart rate, with a respiratory exchange ratio ≥ 1.0 for children and ≥ 1.1 for adolescents. Physical deconditioning was defined as oxygen uptake (VO2) < 80% of predicted at peak exercise, without cardiac impairment or ventilatory limitation. Exercise-induced bronchoconstriction (EIB) was defined as a forced expiratory volume in one second ≥ 10% lower than the baseline value at 5, 10, 20, and 30 minutes after CPET. RESULTS: We evaluated 20 patients with SRA and 19 controls. In the sample as a whole, the mean age was 12.9 ± 0.4 years. The CPET was considered maximal in all participants. In terms of the peak VO2 (VO2 peak), there was no significant difference between the patients and controls, (P = 0.10). Among the patients, we observed isolated EIB in 30%, isolated physical deconditioning in 25%, physical deconditioning accompanied by EIB in 25%, and exercise-induced symptoms not supported by the CPET data in 15%. CONCLUSION AND CLINICAL RELEVANCE: Physical deconditioning, alone or accompanied by EIB, was the determining factor in reducing exercise tolerance in patients with SRA and was not therefore found to be associated with a lack of asthma control.
ABSTRACT
Objetivo: avaliar o valor do pico de fluxo expiratório, obtido através de medidores portáteis, como método alternativo de acompanhamento da função oulmonar na fibrose cística. Métodos: quarenta e nove pacientes, de 5 a19 anos, clinicamente estáveis e aptos a realizar a manobra para obtenção do pico do fluxo foram incluídos no estudo. Na mesma visita, pontuou-se o escore de Shwachman-Kulczycki e registrou-se o valor do pico do fluxo expiratório. Analisou-se a correlação entre esses dois parâmetros pele regressão linear, com nível de significância de p= 0,05. Resultados: obteve-se uma correlação discreta, mas estatisticamente significante, entre os valores absolutos e percentuais desses parâmetro funcional com o escore clínico-radiológico (r=0,31, p=0,02 e r=0,30, p=0,03, respectivamente). Conclusões: conclui-se que a significância estatística observada não corresponde necessariamente a uma relevância clínica e, portanto, a função pulmonar na fibrose cística deve ser avaliada pela espirometria convencional
Subject(s)
Humans , Child, Preschool , Child , Adolescent , Cystic Fibrosis , Peak Expiratory Flow RateABSTRACT
OBJECTIVE: To verify the role of peak expiratory flow, measured through portable meters, as an alternative test to assess pulmonary disease in cystic fibrosis. METHODS: Forty-nine patients aged five to 19 years old in stable health condition and able to perform the peak expiratory flow maneuver were included. In the same visit, Shwachman-Kulczycki score was recorded. Linear regression was used to assess the correlation between the Shwachman-Kulczycki score and the peak expiratory flow rate. A P value of 0.05 was considered to be significant. RESULTS: A slight, but statistically significant correlation between absolute and percent values for this functional parameter and the Shwachman-Kulczycki score (r = 0.31, P = 0.02 and r = 0.30, P = 0.03, respectively) was found. CONCLUSIONS: Although this correlation was statistically significant, these findings are not clinically relevant, i.e., the lung involvement in this disease should be assessed by classic pulmonary function tests, such as spirometry.
