THE IMPACT OF PULMONARY FUNCTION TESTS ON EARLY CLINICAL OUTCOMES AFTER SURGERY OF THE ASCENDING AORTIC ANEURYSM

Objective : To evaluate the impact of preoperative pulmonary function tests (PFTs) on clinical outcomes in patients undergoing surgery for ascending aortic aneurysm. Methods: 321 patients undergoing surgery for ascending aortic aneurysm were included into the study. All patients underwent PFTs before the surgery. By analysing pulmonary function, the types of respiratory dysfunction were determined based on forced expiratory volume (FEV1) in one second and forced vital capacity (FVC), according to the recommendations of the American and European Respiratory Societies. The criterion for obstructive pattern was a FEV1/FVC ratio <70%, restrictive pattern was defined as reduced VC (vital capacity), FVC <80% while maintaining normal FEV1/FVC ratios, and mixed pattern was characterized by reduced FEV1, FVC <80% and a FEV1/FVC ratio ≤70%. An analysis of the relationship between PFTs and early clinical outcomes of surgical treatment was performed. Results : PFTs were abnormal not only in 74 patients with a diagnosed chronic obstructive pulmonary disease (COPD) but also in patients without COPD (64 patients). In this group, the obstructive pattern was most frequently observed in 14.2% patients, while restrictive and mixed patterns were detected in 6.5% and 5.3% of cases, respectively. According to multifactorial regression analysis, decreased forced vital capacity, restrictive and mixed patterns, duration of cardiopulmonary bypass, aortic clamping time, obesity, type I aortic dissection, and Marfan syndrome significantly increased the duration of mechanical ventilation, stay in the intensive care unit (ICU), and hospital length of stay. Concomitant COPD increased the frequency of respiratory failure after surgery (p = 0.02) and the rate of mortality (p = 0.036). Conclusions: Assessment of preoperative PFTs prior to surgery allows to predict the complicated outcomes, thus facilitating perioperative planning.