Cardiorespiratory complications after coronary artery bypass grafting

Aim. The study was designed to analyze the relationship between a baseline function of the respiratory system and the incidence of cardiorespiratory complications in patients with coronary artery disease following planned coronary artery bypass grafting under cardiopulmonary bypass. Methods. A prospective cohort of 662 coronary artery disease patients was studied after approval by the local ethics committee. The patients were divided into 3 groups depending on the presence of respiratory diseases and ventilation disorders. The 1st group included 48 (7.2%) patients with respiratory system pathology having no obstructive disorders. The 2nd group had 248 (37.5%) patients with pulmonary diseases and respiratory obstruction. The 3rd group comprised 366 (55.3%) patients without diseases and instrumental signs of ventilation disorders. Results. The largest amount of postoperative complications was observed in patients with bronchial obstruction. Thus, respiratory complications in this group accounted for 20.9% vs. 8.3% (р = 0.036) of patients with respiratory pathology but without ventilation disorders and 4.6% (р = 0.001) of patients with isolated coronary artery disease. The development of cardiac complications had no differences among the patients with pulmonary diseases (35.4% and 48.8%, р>0.05) regardless of the presence of respiratory obstruction, but as compared to the patients without indications of respiratory system pathology, the number of complications prevailed in patients with bronchial obstruction (48.8% and 25.4%; р = 0.001). The patients of these groups differed in the incidence of such complications as development of lower respiratory tract infections [nosocomial pneumonia (5.2% and 2.3%, р = 0.024), acute bronchitis and/or recrudescence of chronic bronchitis 14.1% and 2.9%; р = 0.001)], pneumothorax (4.1% and 0.6%, р = 0.006), as well as in the duration of artificial pulmonary ventilation (1003.7 min vs. 781 and 747.6 min, with p equaling 0.003 to 0.004). These complications more often developed in patients with respiratory obstruction, the incidence of complications was the same among the patients with the burdened respiratory history without ventilation disorders and the patients with isolated coronary artery disease. A similar tendency was observed when comparing the incidence of cardiac complications development. Paroxysms or a persistent form of atrial fibrillations (29% and 15.8%; р = 0.001), as well as decompensation of heart failure (25.4% and 13.9%; р = 0.001) were the most frequent complications. Conclusion. The presence of respiratory obstruction is an unfavorable prognostic factor for postoperative cardiorespiratory complications.