Risk factors and pathogen distribution of nosocomial infection in adult patients undergoing extracorporeal membrane oxygenation after cardiac surgery

Abstract

Objective To analyze the risk factors and pathogen distribution of nosocomial infection in adult patients undergoing extracorporeal membrane oxygenation (ECMO) after cardiac surgery. Methods The clinical data of 325 patients who underwent ECMO support in the Department of Adult Cardiac Surgery of Beijing Anzhen Hospital from January 2012 to December 2017 were retrospectively analyzed. There were 132 patients with nosocomial infection (infected group) and 193 patients without nosocomial infection (non-infected group). Multivariate logistic analysis was used to analyze the risk factors of nosocomial infection, and the distribution of pathogens in infected patients was also analyzed. Results Among 132 infected patients, 67 cases (50.76%) had respiratory infection, 40 cases (30.30%) had blood infection, 15 cases (11.36%) had surgical wound infection, and 10 cases (7.58%) had urinary tract infection. The case fatality rates of the infected group and non-infected group were 61.37% (81/132) and 52.85% (102/193), respectively (χ2=6.356, P<0.05). Univariate analysis showed that long operation time, application of extracorporeal circulation and long-term ECMO support were associated with nosocomial infection. Multivariate logistic regression analysis found that ECMO time (OR=5.565, 95% CI=2.868-10.799, P<0.01) was an independent risk factor for nosocomial infection after ECMO treatment in adult patients after cardiac surgery. Among the 132 infected patients, 364 strains of pathogens were detected, of which 233 were Gram-negative bacteria, including 79 strains of Acinetobacter Baumann (33.9%) and 32 strains of K. pneumoniae (13.73%); 101 strains were Gram-positive bacteria, including Streptococcus aureus (14.85%), Micrococcus (14.85%) and catarrhal bacteria (14.85%); 30 strains were fungi and Candida albicans accounted for 70% of fungi infections. Conclusion The long ECMO support time is an independent risk factor for ECMO-related hospital infections in adult patients undergoing cardiac surgery, and the pathogens are mainly Gram-negative bacteria. Key words: Cross infection; Risk factors; Extracorporeal membrane oxygenation; Cardiac surgery; Etiology analysis