Pulmonary function
Spirometry was performed by KOKO Sx1000® device (n-Spire-HealthTM, Longmont, USA) previously calibrated according to recommendations.12 The variables analyzed were forced vital capacity (FVC), forced expiratory volume in the first second (FEV1) , FEV1 / FVC ratio, forced expiratory flow between 25-75% of FVC (FEF 25-75%) and peak expiratory flow (PEF)12, 13 Values were expressed in absolute values and as a percentage of the predicted value.12
Maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured with a manovacuometer (GERAR®, scale between +120 to –120cmH2O) following the guidelines.14 To measure MIP, maneuvers were performed from the residual volume; and, to measure MEP from total lung capacity. The patient was asked for a maximum inspiratory or expiratory effort. At least five maneuvers were performed or until reproducible values were obtained.8 The best value was used for analysis. Values are expressed in absolute terms and as a percentage of the predicted value.15