Study on the distribution,drug resistance,and related influencing factors of pathogens causing pulmonary infections after coronary artery bypass grafting

CHONG Xu-fang; LYU Xiang-ni

doi:10.3969/j.issn.1672-5301.2025.03.004

Abstract：Objective To examine the drug resistance and distribution of the pathogens that cause pulmonary infections following coronary artery bypass grafting(CABG),as well as the factors that influence these infections.Methods A total of 1488 patients who received CABG treatment at Cardiovascular Surgery Department of the First Affiliated Hospital of Air Force Medical University between September 2022 and August 2024 were the subject of a retrospective study.Depending on whether they experienced a pulmonary infection following surgery,patients were split into two groups:45 infected patients and 1443 uninfected patients.Compile patient clinical data,analyze the distribution of pathogens in the infection group,perform drug sensitivity testing,and use Logistic regression analysis to determine risk factors for postoperative pulmonary infection following CABG.Results In 45 patients with pulmonary infections,58 different strains of pathogenic bacteria were found.Of these,47(81.03%)were gram-negative bacteria,primarily Klebsiella pneumoniae,Pseudomonas aeruginosa,and Burkholderia cepacia,8(13.79%)were gram-positive bacteria,and 3(5.17%)were fungi.According to the results of the drug sensitivity test,Pseudomonas aeruginosa was extremely sensitive to cefoperazone/sulbactam,meropenem,and piperacillin,whereas Klebsiella pneumoniae was extremely sensitive to imipenem,meropenem,azuron,levofloxacin,and amikacin.Burkholderia cepacia was the most cefotaxime-sensitive(all<10%).In this study,Klebsiella pneumoniae and Pseudomonas aeruginosa displayed resistance to other antibiotics ranging from 10%to 50%.Burkholderia cepacia has a high resistance rate to cefoperazone/sulbactam,cefepime,and imipenem,all of which are greater than 70%.Additionally,Burkholderia cepacia is naturally resistant to tranexamic acid and amikacin.Multiple factor analysis revealed that the following independent risk factors for pulmonary infection following CABG surgery were found to be significant:hemoglobin[OR=0.947,95%CI 0.921-0.973],cardiopulmonary bypass time(OR=1.094,95%CI 1.069-1.120),tracheal intubation time≥3 d(OR=0.175,95%CI 0.068-0.451),and postoperative acute kidney injury[OR=0.155,95%CI 0.062-0.388](P<0.05).Conclusion Following CABG surgery,pulmonary infections are rather common,and the majority of the pathogens are gram-negative bacteria.There is a limited selection of anti-infective medications,and clinical use should be cautious due to the pathogens'distribution characteristics.Independent risk factors for pulmonary infection following CABG surgery include hemoglobin,cardiopulmonary bypass time,tracheal intubation time≥3 days,and postoperative acute kidney injury.To improve prognosis,clinical practice should actively take the required precautions.