Effects of conventional physiotherapy, continuous positive airway pressureand non-invasive ventilatory support with bilevel positive airway pressureafter coronary artery bypass grafting

Background: Coronary artery bypass graft (CABG) surgery with the use of mam mary arteries is associated with severe alteration of lung function paramet ers. The purpose of the present study was to compare the effect on lung fun ction tests of conventional physiotherapy using incentive spirometry (IS) w ith non-invasive ventilation continuous positive airway pressure (CPAP) and with non-invasive ventilation on bilevel positive airway pressure (BiPAP o r NIV-2P). Methods: Ninety-six patients were randomly assigned to 1 of 3 groups: NIV-2 P (1 h/3 h), CPAP (1 h/3 h) and IS (20/2 h). Pulmonary function tests and a rterial blood gases analyses were obtained before surgery. On the 1st and 2 nd postoperative days, these parameters were collected together with cardia c output and calculation of venous admixture. Results: For the 3 groups a severe restrictive pulmonary defect was observe d during the Ist postoperative day. On the 2nd postoperative day, in opposi tion to IS, intensive use of CPAP and NIV-2P reduced significantly the veno us admixture (P<0.001) and improved VC, FEV1 and PaO2 (P<0.01). Conclusion:We conclude that preventive use of NIV can be considered as an e ffective means to decrease the negative effect of coronary surgery on pulmo nary function.