Objective: To evaluate whether the application of bilevel positive airway pressure in the postoperative period of bariatric surgery might be more effective in restoring lung volume and capacity and thoracic mobility than the separate application of expiratory and inspiratory positive pressure. Method: Sixty morbidly obese adult subjects who were hospitalized for bariatric surgery and met the predefined inclusion criteria were evaluated. The pulmonary function and thoracic mobility were preoperatively assessed by spirometry and cirtometry and reevaluated on the 1st postoperative day. After preoperative evaluation, the subjects were randomized and allocated into groups: EPAP Group (n=20), IPPB Group (n=20) and BIPAP Group (n=20), then received the corresponding intervention: positive expiratory pressure (EPAP), inspiratory positive pressure breathing (IPPB) or bilevel inspiratory positive airway pressure (BIPAP), in 6 sets of 15 breaths or 30 minutes twice a day in the immediate postoperative period and on the 1st postoperative day, in addition to conventional physical therapy. Results: There was a significant postoperative reduction in spirometric variables (p<0.05), regardless of the technique used, with no significant difference among the techniques (p>0.05). Thoracic mobility was preserved only in group BIPAP (p>0.05), but no significant difference was found in the comparison among groups (p>0.05). Conclusion: The application of positive pressure does not seem to be effective in restoring lung function after bariatric surgery, but the use of bilevel positive pressure can preserve thoracic mobility, although this technique was not superior to the other techniques.

Introduction: Obesity and aging may cause changes in lung function. Objective: to assess whether body mass, body mass index (BMI) and age influences vital capacity (VC) and forced expiratory volume in the first second (FEV 1 ) in women. Methods: 81 women aged between 30 and 75 years participated in the study. The sample included obese and morbidly obese, non-smoking, sedentary individuals without chronic lung disorders. Anamnesis, anthropometric and spirometric evaluations were performed. Statistical analysis was carried out using the Pearson correlation and Spearman tests, adopting a significance level of 5%. Results: It was observed that age had significant and negative correlations with VC and its components: inspiratory reserve volume (IRV), expiratory reserve volume (ERV) and tidal volume (TV), and with FEV 1 . There was also a significant positive correlation between body mass and VC and IRV and a significant negative correlation between BMI and ERV. Conclusion: Pulmonary function declines over time. Body mass appears to exert a greater influence on IRV, whereas a greater BMI is associated with a decline in ERV.