Statistical analysis
For data analysis, the Statistical Package for Social Sciences (SPSS) version 20.0 was used. Normality was analyzed using the Shapiro-Wilks test. Categorical variables were verified using the Chi-square. Continuous data were expressed as mean and standard deviation. To assess the oxygenation, functional and length of stay, intra and intergroup, the paired Student’s t-test and the independent test were used, respectively. The variables pulmonary complications and mortality were assessed using the Chi-square. A p <0.05 was considered significant.