OBJECTIVE: To compare the dynamic and static compliance, airway resistance values (Cdyn, Cst and Raw) and to gas exchange index (PaO2/FiO2) postoperative to Coronary Artery Bypass Surgery Graft (CABG) with normality parameters, and to compare the values of these variables between groups with and without preoperative risk factors. METHOD: Questioning the patients about previous pulmonary diseases, respiratory symptomology, smoking, and comorbidities. After CABG measures were taken for Cdyn, Cst, Raw and the PaO2/FiO2. Variables were compared with normality and related to pre- and postoperative variables by the Mann-Whitney non-parametric Test and the Test for one proportion (p<0.05). RESULT: Seventy patients were evaluated (61% men) aged between 26 and 77 years. With regard to normality, diminution of Cdyn and Cst was presented in 64 and 66 patients, respectively, and increase of Raw in 24. Approximately 50% presented reduction in PaO2/FiO2. There was no significant difference in postoperative variables about previous pulmonary diseases, respiratory symptomology and smoking. In patients with comorbidities was PaO2/FiO2 significantly less and, in men, Cdyn and Cst were greater than in women. CONCLUSION: Pulmonary compliance is diminished in more than 90% of patients that undergo CABG; and the airway resistance is increased in one third of them. The gas exchange index is reduced in half of them. The present previous pulmonary diseases, respiratory symtomology and smoking did not influence mechanical variables, but the gas exchange index is influence by the presence of comorbidities.
Respiratory mechanics; Thoracic surgery; Respiration, artificial; Postoperative complications; Myocardial revascularization
