CVC provides effective venous access for patients in critical condition and those with renal failure and cancer. It improves the success rate of resuscitation, alleviates the pain of patients, and prolongs their survival time. The International Nosocomial Infection Control Consortium (INICC) reported CLABSI is 4.9/1000 catheter days [1, 2]. The incidence of CLABSI in China is 5–15% and 2.9–11.3/1000 catheter days . One study in Argentina found a 5.4% incidence of CLABSI and an infection rate of 8.7/1000 catheter days . In this study, the incidence of CLABSI was 2.32%, and the infection rate of indwelling catheters was 1.64/1000 catheter days, which was consistent with the results of CLABSI epidemiological studies in the United States.
The patients with CLABSI in this study were younger and had severer conditions. Dialysis catheter is used for patients with renal failure requiring alternative therapy. Conventional CVC is more commonly used for monitoring treatment of cardiac failure. PICC and PORT are more commonly used for patients with malignant tumors, in which the indwelling time is long. In this study, age, severity, and comorbidities were included in the multivariate analysis, and the results were consistent with the univariate results. The number of CVC type and the duration of CVC were correlated with the incidence of CLABSI. A previous study showed that reducing the number of CVC and the duration of indwelling catheter can reduce the incidence of CLABSI .Parameswaran et al  found that the rate of femoral vein, intrajugular vein, and subclavian vein catheter-related infections was 33.3%, 22.2%, and 21.3%, respectively.Lorente et al  analyzed 2595 patients found that the femoral vein had a higher risk of CRBSI than the internal jugular vein and the subclavar vein.This study also confirmed a higher risk of CRBSI in the femoral vein.
Once CLABSI occurs, it requires more intensive antibiotic treatment, so it is also correlated with the number of antibiotic types and the duration of antibiotic treatment. Lee JH et al. also confirmed that antibiotic use was an independent risk factor for CLABSI . Huerta et al. also found a significant association between duration of antibiotic use and early mortality and relapse .
Many studies have shown that CLABSI can significantly increase mortality and prolong hospital stay . However, this study found an increase in in-hospital mortality in the CLABSI group, which was not statistically significant compared with the NO CLABSI group. The outcome of this study was in-hospital mortality. Without out-of-hospital follow-up, there may be deviations in mortality. The improvement of CLABSI prevention concept and treatment level can greatly reduce morbidity and mortality. A Study study in South Korea reduced the average CLABSI pooling rate from 3.40 in 2006 to 2.20/1,000 catheter days in 2015 . In the United States, many randomized controlled trials focused on preventing CLABSI, with a 50% decline in CLABSIs between 2008 and 2014 , and the mortality of CLABSIs decreased . Most of the previous studies are aimed at conventional CVCs, excluding PICC and PORT. The study has confirmed that the incidence of CLABSI caused by PICC is significantly lower than that of other types of CVC. The in-hospital mortality of PICC CLABSI and PORT CLABSI has not been well studied, thus affecting the overall mortality. CVC is increasingly maintained outside the hospital, and out-of-hospital CLABSI needs further study.
In this study, the positive rate of catheter culture was significantly higher than that of blood culture. The six most common microorganisms in catheter culture were Staphylococcus epidermidis, Staphylococcus aureus coag, Pseudomonas aeruginosa, Serratia, and Enterobacter aerogenes. G + cocci accounted for 80.48%, followed by G- bacilli and fungi. Fungi were mainly yeast. A number of studies in China showed that the most common microbe was Acinetobacter, followed by Staphylococcus epidermidis and Candida albicans . A study in Spain showed that G + cocci accounted for the majority, followed by G- bacilli and yeasts , which was consistent with our results. According to CLABSI data from the Centers for Disease Control and Prevention and the National Healthcare Safety Network, fungal infections are high in adult ICUs, and Enterobacteriaceae and fungi are increasing in oncology wards . Due to the different prevention and treatment plans of hospitals in different regions, the distribution of pathogenic microorganisms may be different. Iatrogenic factors may greatly influence catheter microbial colonization and catheter-associated infections. Hospital managers need to strengthen environmental and human monitoring and nosocomial infection control.
The distribution of microorganisms in blood culture was not consistent with that in catheter culture. The proportion of G + cocci decreased, while those of G- bacilli and fungi increased. Staphylococcus, Enterococcus, Staphylococcus aureus coag, Escherichia coli, Candida albicans, and intestinal bacteria increased significantly. Enterogenic bacteria enter the blood after intestinal barrier destruction, which is an important mechanism of blood-borne infection . The proportion of Candida albicans in fungi increased. Although yeast prevalence has geographical differences, the overall level of yeast prevalence is increasing globally [24, 25]. In addition, repeated exposure to broad-spectrum antibiotics, complex surgical procedures, glucocorticoids, and other factors increases the risk of fungal infections, especially Candida .
The three most commonly monitored antibiotics in the both cultures included gentamicin, erythromycin, vancomycin, The five antibiotics with the highest drug resistance in the both cultures included penicillin G, oxacillin, erythromycin, levofloxacin, and ampicillin. Three kinds of sensitive antibiotics were found: daptomycin, linezolid, and carbapenems (meropenem, imipenem), which are all third-line antibiotics. Other sensitive antibiotics included enzyme inhibitors (piperacillin tazobactam), sulfa (trimethoprim sulfamethoxazole), rifampin (anti-tuberculosis), and amikacin. In the NO CLABSI group and CLABSI group, the distribution of antibiotics used for treatment was consistent, and the difference was not statistically significant. The overall distribution showed that the most commonly used antibiotics were vancomycin, cefepime, piperacillin tazobactam, and cefazolin. The sensitivity of blood culture was 62–82%, and that of catheter culture was 51–91%, with vancomycin and cefazolin having the highest and lowest sensitivities. Studies have shown that on the basis of etiological predictions, early source control, when initiated with antimicrobial therapy, improves prognosis . Antibiotics are often used empirically at the beginning, advocating broad spectrum and high efficiency, and replaced with narrow-spectrum and high-sensitivity drugs according to etiology and drug sensitivity results. To prevent the development of resistance, antibiotic management needs to be followed . At the same time, economic factors should be taken into account. This study showed that the use of antibiotics basically conformed to the results of drug sensitivity. Currently, research on the application of antibiotics for the treatment of CLABSI is insufficient.