Effects of noninvasive mechanical ventilation in pulmonary function and functional capacity after cardiac surgery:A Randomized Controlled trial

INTERVENTION: 54 patients with coronary artery disease who underwent an elective coronary artery bypass grafting submitted an anesthesia and mechanical ventilation, under anesthesia with etomidate and midazolam and maintained with isoflurane and associated with sufentanyl 0.5% to 1% , and under ventilation with tidal volume 8 mL/kg of predict body weight and respiratory rate adjusted to achieve a PaCO2 between 35 and 45 mmHg, without positive end‐expiratory pressure (PEEP) , with a fraction of inspired oxygen (FiO2) between 50 % to 60 % . After surgery, they were ventilated in volume controlled ventilation (VCV) with 12 to 14 breaths per minute, inspiration/expiration ratio of 1:2, PEEP of 5 cmH2O, tidal volume of 8 mL/kg predict weight, pressure support to maintain this volume and FIO2 to maintain the arterial oxygen saturation above 90% . After extubation and other procedures, were underwent a daily program of physical therapy until discharge, with noninvasive mechanical ventilation with bilevel positive pressure (BiPAP) with BiPAP ® Synchrony ® manufactured by Respironics , adjusted: IPAP of 20 cmH2O and EPAP 10 cmH2O , FiO2 to maintain SpO2 > 90%. Continuous Noninvasive Mechanical Ventilation Group: 21 patients on continuous NIV for 6 hours in the immediate postoperative period and 60 minutes twice a day from 1st to 5th postoperative supine with elevated 45° head, adjustable face mask. Intermittent Noninvasive Mechanical Ventilation Group: 19 patients on intermittent NIV for 60 min in the immediate postoperative period and 10 min twice daily from 1st to 5th postoperative supine with elevated 45° head, adjustable face mask. E01.370.386.700 E02.041.625.790.259 Procedure/surgery CONDITION: C14.280.434 heart failure. ; C14.280.434 PRIMARY OUTCOME: Outcome expected:; 1)‐Reduction of the inflammatory response in postoperative coronary artery bypass grafting, assessed by serum levels of Interleukin (IL1, IL6, IL8) and TNFa, C3a, ICAM, CRP, through the samples in the intra‐surgery, after induction of anesthesia and postoperative immediately after extubation and after NIV protocol.; SECONDARY OUTCOME: Expected Outcomes: ; 1)‐Accelerated recovery of volumes and capacities in postoperative coronary artery bypass grafting, assessed by increased forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) compared preoperatively, 1st. 3rd. and 5th. day postoperatively. ; 2)‐Accelerated recovery of respiratory muscle strength in postoperative coronary artery bypass grafting, assessed by increased maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) compared preoperatively, 1st. 3rd. and 5th. day postoperatively. ; 3)‐Improved functional capacity in postoperative coronary artery bypass grafting, assessed by the distance walked during the 6‐minute walk test (6MWT) compared preoperatively and 5th. postoperative day. ; 4)‐Improved tissue perfusion and reduced tissue hypoxia in postoperative coronary artery bypass grafting, assessed by reduced dosages of blood lactate and increased central venous oxygen saturation (ScVO2) collected directly from the central venous catheter in intra‐surgery after induction of anesthesia and postoperative immediately after extubation and after NIV protocol. Outcomes found: ; ; ; 1)‐Improvement of volumes and capacities in postoperative coronary artery bypass grafting assessed by increased forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) compared preoperatively, 1st. 3rd. and 5th. day postoperatively ; 2)‐recovery of respiratory muscle strength in postoperative coronary artery bypass grafting assessed by increased maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) compared preoperatively, 1st. 3rd. and 5th. day postoperatively ; 3)‐Was not found improvement in functional capacity in postoperative coronary artery bypass grafting, assessed by the distance walked during the 6‐minute walk test (6MWT) compared preoperatively and 5th. postoperative day. ; 4)‐Improved tissue perfusion and reduced tissue hypoxia in postoperative coronary artery bypass grafting, assessed by reduced dosages of blood lactate and increased central venous oxygen saturation (ScVO2) collected directly from the central venous catheter in intra‐surgery after induction of anesthesia and postoperative immediately after extubation and after NIV protocol. INCLUSION CRITERIA: Both gender, age between 35 and 75 years; proven coronary disease by coronary angiography; Surgery elective CABG with CPB and use of the LITA; ventricular ejection fraction greater than 50%; Absence of acute pulmonary disease or chronic, patients who, after surgery, keep in spontaneous ventilation on the first day after surgery.