INTRODUCTION
Cardiac surgery (CS) is a widely used treatment process due to the high incidence of cardiovascular disease worldwide1. Among the most common surgeries, coronary artery bypass grafting (CABG) stands out, a procedure that improves the quality of life of patients with symptomatic myocardial ischemia, when one or more coronary arteries are obstructed by atheroma plaques leading to a decrease in blood flow to the heart muscle2. Patients undergoing CABG show significant results, but the vast majority develop postoperative pulmonary disorders3.
After surgery, there is a decrease in ventilatory muscle strength and pulmonary function, causing a negative impact on these patients4. Thus, the appearance of pulmonary complications can cause unfavorable clinical outcomes such as atelectasis, pneumonia, pulmonary edema and acute respiratory failure (ARF), favoring negative functional results5,6. Some factors such as age, overweight, sex, type of surgery and intraoperative conditions can contribute to the development of these complications7.
Noninvasive ventilation (NIV) can be used right after extubation in order to minimize pulmonary dysfunction, reduce the length of stay in the intensive care unit (ICU) and represent an improvement in the functional capacity of these patients8,9,10,11. According to the mechanical ventilation (MV) guideline, NIV should be performed immediately after extubation, however in some services it appears on the first postoperative day as the institution’s protocol12. There is still little evidence for validation in relation to clinical and functional outcomes if NIV immediately after extubation may be more appropriate when compared to that performed in the first postoperative day.
Despite being a recommendation of Brazilian guidelines, the application of NIV immediately after extubation is not yet a reality in most ICUs. Therefore, this work can confirm the importance of this therapy in patients undergoing CABG12. The purpose of this study was to compare the clinical and functional impact of two post-extubation (or prophylactic) non-invasive mechanical ventilation protocols for patients undergoing coronary artery bypass graft surgery.