Pulmonary complications are a major cause of postoperative morbidity and mortality in those patients undergoing operations utilizing cardiopulmonary bypass. The purpose of this study was to evaluate the pulmonary function after myocardial revascularization without cardiopulmonary bypass using a intraluminal shunt. Twenty-three patients with coronary disease were submitted to surgery by this technique and pulmonary function testing was conducted consecutively. The surgeries were performed via a median sternotomy with a reversed saphenous vein and/or an internal mammary artery graft. The age ranged from 36 to 69 years (mean 56,3 years). The group was comprised by 16 men and seven women. The pulmonary function tests consisted of spirometric investigations and blood gases measurements with evaluation of intrapulmonary shunt degree, both analyzed during the preoperative period, at the 4th (PO4) and at the 10th (PO10) postoperative day. In spirometry were determinated the vital capacity (VC), forced vital capacity (FVC), forced expiratory volume at one second (FEV), forced expiratory flow over middle half of FVC (FEF 25-75), coefficient of the one second expiratory volume (FEV/FVC), coefficient of middle expiratory flow (FEF 25-75/FVC) and maximal voluntary ventilation (MVV). The VC showed at the PO4 a mean decrease of 37.80% (p<O,O1) in comparison with the preoperative value and at the PO10 it had an improvement but there was still a mean decrease of 26.85% (p<0,01). The FVC also showed a mean decrease of 38.37% (p<0,01) at the PO4 and an improvement at PO10 when persisted a mean decrease of 28.80% (p<0,01). The FEV1 and the FEF 25-75 were decreased at the PO4 in a mean rate of 36.88% (p<0,01) and 30.47% (p<0,01) respectively. At the PO10 there was a decrease of 29.29% (p<0,01) for the FEV1 and 27.61% (p<O, 01) for the FEF25-75. The maximal voluntary ventilation (MVV) was decrease and it showed a mean rate of 37.40% (p<0,01) at the PO4 and 26.22% (p<0,01) at the PO10. The coefficients FEV/FVC and FEF25:75/FVC showed non-significant alterations. The blood gases measurements showed a reduction in arterial oxygen tension (PaO2) with a mean rate of 12.92% (p<0,01) at PO4 and 10.80% (p<0,01) at PO10. The carbon dioxide tension showed mean reduction at PO 4 of 5.22% (p<O, 05) and at PO10 returned to normal values. The shunt (Q/Q1) increased at the postoperative period at the PO4 mean rate was 69,03% (p<0,01) and PO10 mean rate was 58.73% (p<0,01). In conclusion, all patients showed at PO4 decrease of the spirometric tests (VC, FVC, FEV1, FEF 25-75 and MMV) and the blood gases measurements (PaO2 and PaCO2. There was a increase of the shunt. At the PO10 was observed a improvement in VC, FVC, FEV1, MMV and PaCO2. In relation to the preoperative period whe still found at PO10 changes in VC, FVC, FEV1, FEF 25- 75 , MMV, PaO2 and shunt.
Pulmonary function; Myocardial revascularization; Cardiopulmonary bypass