Multidrug-resistant bacterial infection in adult patients following cardiac surgery: clinical characteristics and risk factors

BACKGROUND: The prevalence of infections with multidrug-resistant organism (MDRO) pose great challenges for anti-infective therapy. Previous research on MDRO infections after cardiac surgery was limited. Therefore, understanding and mastering the clinical characteristics and risk predictors of MDRO infection after cardiac surgery is of great significance for standardized management of perioperative patients. METHODS: The medical records of adult patients with MDRO infection after cardiac surgery from January 2018 to October 2021 were collected, and patients were divided into MDR infection group (n = 176) and non-MDR infection group (n = 233). Univariate and multivariate regression analysis of variables was performed to determine the risk predictors of MDRO infection. RESULTS: The incidence of MDRO infection was 8.6%. Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa were the most common, accounting for 37.3%, 23.5% and 18.0%, respectively. The main infection type were lower respiratory tract infection (LTRI = 29.0%). Univariate analysis showed that underwent coronary artery bypass graft (CABG) (P = 0.001) and secondary operation (P = 0.008), pre-infection exposure to vancomycin (P < 0.001) and linezolid (P = 0.002), combination antibiotics (P < 0.001), four antibiotics in combination (P = 0.005), glucocorticoid use (P = 0.029), preoperative hypoalbuminemia (P = 0.003) were risk factors for post-operative MDRO infection. Multivariate regression analysis showed that underwent CABG (OR = 1.228, 95%CI = 1.056∽1.427, P = 0.008), secondary operation (OR = 1.910, 95%CI = 1.131∽3.425, P = 0.015) and pre-infection exposure to linezolid (OR = 3.704, 95%CI = 1.291∽10.629, P = 0.005) were independent risk predictors for MDRO infection. The risk of MDRO infection increased with the length of stay in the ICU (P < 0.001) and the length of stay before diagnosis of infection (P = 0.003), and the difference was statistically significant. Meanwhile, the length of stay after infection (P = 0.005) and the total length of hospital stay (P < 0.001) were significantly longer in the MDRO infection group, and the all-cause mortality was numerically higher in the MDRO infection group (31.3% versus 23.2%). CONCLUSIONS: The morbidity and mortality of MDRO infection was high in adult cardiac surgery, and many risk factors influence the occurrence of MDRO infection. In the future, clinicians should focus on high-risk patients, strengthen multidisciplinary collaboration on infection prevention and control measures, reduce the morbidity and mortality of MDRO infection, and improve the prognosis of in-hospital patients.