Hiperinsuflação dinâmica em crianças e adolescentes diagnosticadas com fibrose cística em testes clínicos de campo e sua relação com a participação e qualidade de vida

Abstract

The cystic fibrosis (CF) health condition is a progressive genetic disease, caused due to mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, making the mucus thick and sticky, and the lungs are usually most critically affected. Many studies investigated exercise intolerance in individuals with CF and showed several compromised mechanisms, such as musculoskeletal abnormalities, ventilatory limitation, deconditioning, dynamic hyperinflation (DH). Exercise performance must therefore be assessed and the Cardiopulmonary Exertion Test (CPET) is the gold standard tool for this assessment, however when CPET equipment is not accessible field tests can be used such as the Modified Shuttle Test (MST) that correlates with the VO2peak measured during CPET. The purpose of the study is to assess the prevalence of HD using two clinical field tests: SWT and the PAY (Performance Activity in Youth) test, to assess whether these tests are associated with participation and quality of life questionnaires. This is a cross-sectional observational study, in clinically stable children and adolescents diagnosed with fibrosis between 6 and 17 years old. The MST an externally paced walking and running test, and the PAY Test, which consists of five activities: walking, standing up and sitting down, going up and down stairs, doing jumping jacks, shoulder flexion with weight, were performed. To assess DH in the field tests, spirometry was performed with measurement of the inspiratory capacity (IC) before and after each test. It was considered HD when there was a 100ml drop from the IC. Participation Questionnaire at home, school and community – Participation and Environment. Measure for Children and Youth (PEM-CY) and the Cystic Fibrosis Quality of Life Questionnaire (CFQ) were answered by guardians and/or volunteers, depending on age. Statistical significance was considered when p < 0.05. Of the 30 patients evaluated, 16 had mild obstructive disorders (53.3%), 5 had normal spirometry (16.7%), 4 had moderate obstructive disorders (13.3%), 1 volunteer had severe obstructive disorders (3.3 %) and 4 mixed obstructive disorder volunteers (13.3%). On average, the volunteers covered more than 80% of the predicted distance covered in the MST. There was no statistically significant change in IC before and after the PAY test (1.60  0.69L) and the MST (1.57  0.69L), p = 0.57. Only 2 volunteers presented HD in the clinical tests, 1 (one) presented it only in the MST, and the other presented it in the MST and in the PAY test. There was no correlation between the CFQ of children and adolescents and the clinical field tests. However, a correlation was identified in the physical (r = 0.50, p = 0.04), treatment) r = 0.60, p = 0.01) and health (r = 0.68, p = 0.004) domains of the CFQ answered by those responsible with the distance covered in the MST. Additionally, significant correlations were observed between volunteers' participation at home (PEM-CY) and the PAY test (r = -0.41, p = 0.02). In children and adolescents diagnosed with CF with mild airway obstruction, there was a low prevalence of DH during two clinical field trials. The domains of quality of life and participation correlate with the distance covered in the MST and the PAY Test.