The effectiveness of chest physiotherapy techniques in pulmonary function recovery after mitral valve surgery: comparative study between breathing exercises and incentive spirometry

INTRODUCTION: Pulmonary expansion techniques are routinely used in the recovery of pulmonary function in the postoperative period of heart valve surgery. Our hypothesis is that the techniques of breathing exercises and incentive spirometry present effects of non-inferiority in pulmonary function when applied in patients evaluated by a risk score, which present postoperative pulmonary dysfunction features and were classified as level 1 of physiotherapeutic assistance. OBJECTIVES: a) to compare the pulmonary function of patients with postoperative pulmonary dysfunction, submitted to the techniques of breathing exercises and incentive spirometry in the postoperative mitral valve surgery; b) to study the influence of the type of mitral valve disease, stenosis and regurgitation in the pulmonary function evolution; c) to compare the pulmonary function evolution between patients with severe and non-severe pulmonary arterial hypertension. METHODS: The data were collected in the preoperative, on the return to the patient's ward (postoperative) and 5 days after intervention of the techniques of lung expansion. The patients were randomized to the EXE group (breathing exercises) and IS group (incentive spirometry) performed three sets of exercises with 10 repetitions, followed by cough, mobilization exercises and ambulation. Pulmonary function was assessed by spirometry, oxygenation, maximal respiratory muscle pressures and pulmonary collapse using chest X-rays. The statistical analysis ANOVA for repeated measures, chi-square test or Fisher, Student's t-test for significance level of p <0.05. RESULTS: Of 153 patients 116 were included and classified as level 1 physiotherapeutic assistance with 59 patients (51%) in the EXE group and 57 (49%) in the IS group. There were no statistically significant differences between groups, except for the thoracoabdominal motion in the EXE group had a greater number of cases with earlier recovery. Lung function decreased significantly in the postoperative period, with partial recovery at 5th day of intervention (p <0.05). Heart and respiratory rate remained high (p <0.05). The lung collapse rates before and after the study were 61% and 43% in the EXE group and 51% and 35% in IS group. There were no statistically significant differences when we compared the patients with stenosis and mitral regurgitation. PAP≥50mmHg patients (n= 55) had mild restrictive ventilatory pattern and reduced oxygenation in the pre-operative. CONCLUSIONS: The evolution of pulmonary function of EXE and IS groups with pulmonary dysfunction, classified by physiotherapeutic assessment system showed non-inferiority between techniques in the mitral valve surgery postoperative. The recovery of pulmonary function was not different between mitral stenosis and regurgitation. The presence of severe pulmonary hypertension no affects the evolution of pulmonary function in patients in the postoperative mitral valve surgery.