Evaluation of pulmonary function in patients following on- and off-pump coronary artery bypass grafting

Objective: To evaluate and compare the pulmonary function in patients following onand off-pump coronary artery bypass grafting (CABG). Method: Thirty patients (mean age 56.76 ± 10.20 years) were allocated to two groups, according to the use or not of cardiopulmonary bypasses: group A (n=15) off-pump and group B (n=15) on-pump, with all patients undergoing preand post-operative evaluation of the pulmonary function as well as arterial blood gases analysis. Forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1) were recorded in the preoperative period, and on the first, third and fifth postoperative days. Blood gases were evaluated in the preoperative period and on the first postoperative day. Results: In both groups, significant falls in the FVC and FEV1 were detected up to the fifth postoperative day (p<0.05). When both groups were compared, the decreases in FCV and VEF1 were higher in group B (p<0.05). PaO2 values and the PaO2/FiO2 ratio presented significant drops on the first postoperative day in both groups, however the fall was higher in group B (p<0.05). Conclusion: Patients who undergo CABG, regardless of the use of CPB, display a significant reduction in the postoperative pulmonary function. However, patients who undergo off-pump CABG have a better preservation of the lung function compared to on-pump CABG. Descriptors: Myocardial revascularization. Extracorporeal circulation. Respiratory function tests. Resumo Objetivo: Avaliar e comparar a função pulmonar em pacientes submetidos à cirurgia de revascularização do miocárdio (RM) com e sem circulação extracorpórea (CEC). Método: Trinta pacientes (média de idade 56,76±10,20 anos) foram alocados em dois grupos, de acordo com a utilização ou não da CEC: grupo A (n=15) sem CEC e grupo