Bronchial obstruction syndrome as a predictor of mortality in cardiac surgery: interim results of prospective cohort study

Objective. To investigate the effect of bronchial obstruction syndrome on perioperative characteristics in patients undergoing coronary artery bypass grafting (CABG). Methods. Body plethysmography and spiroergometry at rest were used to study respiratory function and consumption of 02. To evaluate the effectiveness of pulmonary ventilation, the oxygen utilization coefficient of (02CU) was calculated in 178 patients prior to scheduled surgery. The relationship of external ventilation parameters and perioperative clinical characteristics was analyzed. Results. A bronchial obstruction syndrome was detected in 30 (16.9%) patients, with 21 (11.2%) of them having no chronic obstructive pulmonary disease diagnosis. 4 patients (2.3%) with obstructive pulmonary disease had no bronchial obstruction. Thus, chronic obstructive pulmonary disease was misdiagnosed in 13.5% cases. In patients undergoing isolated CABG, negative relationship was revealed between the Tiffno index and hospital stay (regression coefficient-6.9, 95%, confidence interval -14.4... 0.6; p = 0.07). In patients operated with the myocardium stabilized, bimammary grafting tended to increase hospital stay by an average of 4.3 days (95% Cl 1.5-7.1; p=0.003). The majority of patients had a low 02CU. 02CU lower than 16.2 ml/l is associated with an increased risk of postoperative atrial fibrillation (AF) in the postoperative period (OR 2.96; 95% Cl 1.01-9.83; p = 0.04). No significant associations were observed between the degree of bronchial obstruction and the number of perioperative complications. Conclusion. The degree of bronchial obstruction could be positively associated with the length of hospital stay. A critically low level of 02CU is explained by an increased risk of postoperative AF. Further research might result in the identification of predictors for respiratory complications and long-term mortality in patients after CABG.