Effect of Different Levels of Peep on Oxygenation during Non-Invasive Ventilation in Patients Submitted to CABG Surgery: Randomized Clinical Trial

Introduction: During and after coronary artery bypass grafting, a decline in multifactor lung function is observed. Due to this fact, some patients may benefit from non-invasive ventilation after extubation targeting lung expansion and consequently improved oxygenation. Objective: To test the hypothesis that higher levels of positive end expiration pressure during non-invasive ventilation improves oxygenation in patients undergoing coronary artery bypass grafting. Methods: A randomized clinical trial was conducted at Instituto Nobre de Cardiologia in Feira de Santana. On the first day after surgery, the patients were randomized: Group PEEP 10, Group PEEP 12 and Group PEEP 15 who underwent non-invasive ventilation with positive end expiration pressure level. All patients were submitted to analysis blood pressure oxygen (PaO2), arterial oxygen saturation (SaO(2)) and oxygenation index (PaO2/FiO(2)). Results: Thirty patients were analyzed, 10 in each group, with 63.3% men with a mean age of 61.1 +/- 12.2 years. Mean pulmonary expansion pre-therapy PaO2 was generally 121.9 +/- 21.6 to 136.1 +/- 17.6 without statistical significance in the evaluation among the groups. This was also present in PaO2/FiO(2) and SaO(2). Statistical significance was only present in pre and post PEEP 15 when assessing the PaO2 and SaO(2) (P=0.02). Conclusion: Based on the findings of this study, non-invasive ventilation with PEEP 15 represented an improvement in oxygenation levels of patients undergoing coronary artery bypass grafting.