A meta-analysis of risk factors for a Dacron-cuffed catheter related infection in hemodialysis

Long-term catheters for hemodialysis are also known as tunneled central venous catheters (TCVC). Dacron sleeves are installed outside the catheters. When the dacron sleeves are inserted, a subcutaneous tunnel needs to be made. It can also reduce the catheter with dacron sleeve protruding. TCVC catheterization is widely used in clinic because it solves the problem of poor vascular condition and no vascular channel due to repeated fistula failures. However, due to the long catheter indwelling time, the catheter-related infection (CRI) rate increases, which adversely affects the prognosis and also increases the risk of death in hemodialysis patients [1]. Here, we used a meta-analysis to explore the risk factors associated with TCVC CRI in hemodialysis to provide theoretical basis for prevention and treatment of CRI.

Although TCVC overcomes some shortcomings of deep venous catheter and arteriovenous fistula, it also increases the risk of CRI due to long-term indwelling catheter. Infection is one of the known and serious complications of hemodialysis, which can easily induce other complications and lead to the death of patients [15]. Therefore, it is extremely important to correctly understand the risk factors of CRI and actively prevent them. We used meta-analysis to find that the main risk factors of CRI in hemodialysis are combined-diabetes, age, hemoglobin level, catheter indwelling time, serum albumin level, femoral vein catheterization and catheterization times.

Studies [16] have shown that patients with a central venous catheter have a higher incidence of infectious complications than those with a fistula. The results of our analysis showed that the number of catheterization was one of the main risk factors for the occurrence of CRI, and the OR value reached 5.40 (2.65 ~ 11.02). Repeated puncture during catheterization could cause damage to subcutaneous tissues and the inner wall of blood vessels, thus increasing the opportunity for bacterial invasion [17]. Among patients receiving continuous hemodialysis, the incidence of CRI is relatively low, and it is not significantly affected by the first new vein puncture [18]. Therefore, it is necessary to strengthen the operation proficiency of catheterization personnel, strive to use the least number of catheterization times, and achieve satisfactory catheterization effect. The more skilled the catheterist is, the fewer vascular insertions will be made, and the more strictly regulated aseptic procedures will reduce infection [19]. In addition, due to the lack of long-term indwelling catheter nursing awareness and professional knowledge, non-inpatient patients with TCVC catheterization have poor awareness of catheter maintenance, which will increase the risk of infection when the catheter outlet site is flooded, the film is damaged and loose, etc., such as unplanned operations such as extubation and re-catheterization.

Our study found that the OR values of CRI at the site of catheter indwelling (femoral vein catheterization) and diabetes were 3.29 and 1.94, respectively, second only to the number of catheterization. Patients with this kind of disease should develop good personal hygiene habits, keep the catheterization site dry and clean, and patients with femoral vein catheterization can easily lead to indwelling catheter slip due to vigorous activities when getting up. Therefore, all patients, especially those discharged from hospital with catheter, should be provided with standard education on infection prevention, and patients with femoral vein catheterization should be advised to exercise as little as possible and pay attention to personal hygiene.

Our study showed that long catheter indwelling time was an important independent risk factor for CRI. Some studies [20] have shown that patients undergoing hemodialysis through tunnel catheterization are prone to Gram-positive CRI, and the pathogenic bacteria are mainly coagulase negative Staphylococcus, and the pathogens mainly come from the skin of the puncture site and the hands of catheterizers. During summer catheterization, the reproduction rate of pathogenic microorganisms in the operating environment can be significantly accelerated due to the high ambient temperature, while during winter catheterization, the incidence rate of CRI can be increased due to the reduced frequency of skin cleaning. Therefore, sealing the tube with citrate combined with antibiotics during catheterization can reduce the risk of infection associated with long-term indwelling catheter [21]. When catheter infection is highly suspected, intravenous empiric antibiotic treatment is given immediately and antibiotic type is adjusted according to blood culture results. For clinical staff, hand hygiene should be checked monthly and hand hygiene reports should be shared. Other studies [22] confirmed that there was a positive correlation between the duration of catheter indentation and the occurrence of CRI, with the duration of catheter indentation > 15d, and the incidence of CRI could reach more than 20%. The catheter can not only form a channel connecting the body with the outside world, which can provide convenience for pathogen invasion, but also, due to the repeated opening of the port, pathogens can successfully invade the blood circulation and cause systemic infection through the blood circulation [23].

We found that low serum albumin was another important risk factor for CRI, and the OR value of low serum albumin for CRI was 2.26. Albumin can effectively evaluate the nutritional status and death risk of dialysis patients, and patients with low albumin have a higher risk of infection [24]. In our study, age and low hemoglobin level were also independent risk factors for CRI, with OR values of 2.38 and 1.82, respectively, which reflected the patient's physical condition and nutritional level. As people age, they are more likely to experience multiple organ dysfunction, malnutrition, weakened and weakened immune function, which increases the risk of catheter infection. More than 500,000 Chinese patients have received renal replacement therapy, and more than 90% of them suffer from renal anemia. Anemia can increase the incidence of cardiovascular complications in dialysis patients, reduce the quality of life and increase the mortality of dialysis patients. Moreover, anemia reflects the poor nutritional status of patients, weak resistance and easy occurrence of CRI. Therefore, in clinical work, it is necessary to improve the relevant examination of pre-dialysis albumin and hemoglobin, arouse the attention of patients and their families, and timely improve the malnutrition of pre-dialysis patients, so as to reduce the infection rate and mortality of hemodialysis patients.

In clinical work, it is found that CRI is not only affected by a single factor. TCVC hemodialysis patients are mostly patients with advanced renal disease complicated with other underlying diseases, and the interaction between multiple risk factors often leads to increased difficulties in clinical treatment. In addition to the 7 risk factors identified in this study, another important factor in the occurrence of catheter-associated infection in TCVC is whether stereosis is strictly observed during the use of TCVC and whether the TCVC tunnel is properly protected. Studies have shown that the initiation of standardized nursing protocols and the regular review of compliance with the protocols can significantly reduce the CRI rate of hemodialysis patients [25]. Therefore, education and ability inspection of medical staff in dialysis room should be strengthened. Catheterization personnel should strictly grasp indications of tunnel catheterization and standardize catheterization operation. Nursing staff should carry out strict nursing process to reduce infection caused by improper operation. In addition, education and participation of patients and their families should be strengthened. Joint efforts between health care providers and patients are essential to prevent CRI. For routine infection prevention, an infection control team, namely an infection monitoring team, can be established to monitor and track CRI (electronic database) and help prevent and evaluate the consequences of pathway infection [26].

At present, there are few Meta-analyses on CRI in hemodialysis at home and abroad. Our study had strict inclusion and exclusion criteria. We selected patients with long-term central vein catheterization, namely TCVC catheterization, and selected literatures with logistic multivariate regression analysis, which reduced the influence of confounding factors to a certain extent. The results of our analysis provide a basis for clinical prevention and treatment of CRI in hemodialysis. However, due to the influence of the population and case selection, the results of this meta-analysis need to be verified by multi-center and prospective studies. Moreover, due to inconsistent data recording methods in the included literature, the incidence and risk factors of CRI with different TCVC indwelling times could not be analyzed, and also the lack of consensus on the definition of the risk factors studied and that this heterogeneity influences the generalization of the results derived from the review.

In summary, our present evidence shows that the main risk factors of CRI in hemodialysis were combined with diabetes, hemoglobin level, age, catheter indwelling time, serum albumin level, femoral vein catheter indwelling and catheterization times. In other words, hemodialysis patients are at higher risk of CRI if they have diabetes, or if they have a lower hemoglobin level, or if they are older, or if they have a longer duration of catheterization, or if they have a lower serum albumin level, or if they have a femoral vein catheter, or if they have more catheters.