The aim of the present study was to compare the results of standardization of ventilatory muscle strength data using three international reference values and one Brazilian reference in children and adolescents with cystic fibrosis (CF). This was a retrospective study, which included patients with CF aged 8 to 12 years and in regular follow-up at an outpatient facility. Demographic and anthropometric data were collected. All patients included in the sample should have had ventilatory muscle strength and lung function measured in the past 12 months. The standardization of the results was made using predicted values from each equation. Data were compared using one-way ANOVA. We included 24 patients, 62.5% males, with mean age of 10.5±1.53 years, height 138.0±0.08 cm, weight 34.6±7.9 kg, FEV1 93.29±29.02% and FVC 103.78±26.12%. The maximum inspiratory (MIP) and expiratory (MEP) pressures (cmH2O) observed were 92.1±22.8 and 98.9±24.5, respectively. After standardization by the different equations, we found that the international reference tend to overestimate the findings. The Brazilian equation showed values significantly lower (p<0.05) for MIP and MEP compared to international reference equations, and these would consider MIP values above normal (>100%) in 91.6, 79.1, and 75.0% of the subjects and MEP in 66.6, 87.5 and 50% of them, while using the national equation only 50.0 and 37.5% of subjects were above 100%, respectively. The results of standardization of ventilatory muscle strength in children and adolescents with CF aged 8 to 12 years using international equations overestimate the values of maximal respiratory pressures.
Muscle Strenghth; Respiratory Muscles; Cystic Fibrosis
