Introduction
Bloodstream infections are a significant cause of hospitalizations, illness, and death in patients undergoing hemodialysis. The Centers for Disease Control and Prevention (CDC) has prioritized eliminating these infections through initiatives like the making dialysis safer for patients coalition and the nephrologists transforming dialysis safety initiative in partnership with the American Society of Nephrology. Most bloodstream infections related to vascular access occur in patients using central vein catheters for dialysis.
The CDC's core interventions for preventing these infections are considered the best practices for catheter care in hemodialysis settings and have effectively reduced catheter-associated bloodstream infections. Despite this, the rate of these infections in the United States remains unacceptably high, likely due to inconsistent adherence to strict aseptic techniques or other factors not covered by the CDC's guidelines. Therefore, there is a pressing need for new preventive treatments. In the United States in 2020, over 14,000 bloodstream infections occurred among dialysis patients, with more than one-third caused by staph.
The risk of staph bloodstream infections is heavily influenced by the type of vascular access used to connect a patient’s blood circulation to the dialysis machine. These infections are more prevalent among Black and Hispanic dialysis patients compared to White patients, though factors beyond race and ethnicity may also play a role.
Additionally, staph bloodstream infections are more common in regions of the U.S. with higher poverty rates, more crowded households, and lower education levels, according to U.S. census data. This article explains bloodstream infections during dialysis.
How Does Bloodstream Infection Occur During Dialysis?
Dialysis treatment increases patients' risk of serious infections due to the frequent need to access the bloodstream with needles or catheters (soft plastic tubes inserted into large veins). If germs enter the blood, they can cause severe infections that might lead to sepsis (a potentially life-threatening immune response) and even death.
Various germs can cause bloodstream infections in dialysis patients, with Staphylococcus aureus (staph) being the most common. Staph infections are challenging to treat and can be fatal. Bloodstream infections (BSIs) during dialysis can occur through several pathways, primarily related to the need for frequent and direct access to the bloodstream.
Here is a detailed breakdown of how these infections happen:
1. Vascular Access
Central Venous Catheters (CVCs): These are the most common sites of infection. CVCs are soft plastic tubes inserted into large veins, allowing bacteria to enter the bloodstream. CVCs have a higher risk of infection due to their invasive nature and prolonged use.
Arteriovenous (AV) Fistulas and Grafts: Although less prone to infections than CVCs, AV fistulas and grafts can still become infected. These involve surgical connections between an artery and a vein (fistula) or using a synthetic tube (graft) to join the artery and vein.
2. Breach of Skin Barrier
Needle Insertion: Dialysis requires the repeated insertion of needles into the vascular access site, which breaches the skin barrier. This repeated penetration provides an opportunity for skin bacteria to enter the bloodstream.
3. External Contaminants
Environmental Exposure: The dialysis process involves exposure to the external environment, which can introduce pathogens. Contaminated surfaces, equipment, or supplies can be sources of infection.
Improper Handling: Healthcare staff who use inadequate aseptic technique during catheter insertion, maintenance, or dialysis procedures can introduce bacteria into the bloodstream.
4.Patient Factors
Impaired Immunity: Many dialysis patients have weakened immune systems due to underlying conditions such as diabetes or chronic kidney disease, making them more susceptible to infections.
Comorbidities: Other health conditions can increase the risk of infection.
5. Healthcare Practices
Aseptic Technique: Failure to strictly adhere to aseptic techniques during catheter care, dressing changes, and dialysis procedures can lead to infections.
Staff Education and Training: Insufficient training and awareness among healthcare providers regarding infection prevention protocols can contribute to the incidence of BSIs.
6. Biofilm Formation
Catheter Surfaces: Bacteria can form biofilms on the surfaces of catheters and other medical devices. Biofilms are communities of bacteria more resistant to antibiotics and the immune system, making infections difficult to treat.
How To Prevent Bloodstream Infections?
To mitigate the risk of BSIs, several preventive strategies can be employed:
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Strict Adherence to Aseptic Technique: Ensuring healthcare providers follow stringent infection control practices.
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Education and Training: Continuous staff education and training on infection prevention protocols.
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Antimicrobial Devices: Using antimicrobial-coated catheters and dressings.
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Regular Monitoring and Audits: Implementing checklists and audits to ensure compliance with infection control measures.
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Patient Education: Educating patients on proper care and hygiene practices related to their vascular access sites.
Understanding these pathways and implementing effective preventive measures can significantly reduce the risk of bloodstream infections during dialysis.
What Is Bloodstream Infection?
Bloodstream infections (BSIs) are a significant cause of illness and death among hemodialysis (HD) patients. Those on HD have higher morbidity and mortality rates from BSIs compared to the general population. The annual death rate due to sepsis, a severe BSI complication, is 50 to 100 times greater in this group than in the general population. The most common pathogens found in BSIs among HD patients are Staphylococcus aureus (often methicillin-resistant), coagulase-negative staphylococci (CONS), and other gram-positive bacteria.
HD patients are at a higher risk for BSIs due to various factors, including existing health conditions, weakened immune systems, and the necessity of vascular access for HD therapy, which involves breaking the skin barrier and increased exposure to external and skin pathogens. Although several preventive measures have been introduced recently to reduce BSIs related to vascular access, the infection rate remains high.
What Are Challenges During Dialysis?
The following are the challenges during dialysis:
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High Risk of Infection—Dialysis patients are at a higher risk of developing staph bloodstream infections than those not on dialysis. These infections can be severe or even fatal, and some strains resist the most commonly used antibiotics, rendering these treatments ineffective.
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Racial and Ethnic Gaps - End-stage kidney disease disproportionately impacts Black and Hispanic individuals compared to White individuals. Black and Hispanic people have higher rates of conditions like high blood pressure and diabetes, which elevate their risk of developing end-stage kidney disease. Additionally, there are disparities in the therapies and treatments received by Black and Hispanic patients for this condition. Moreover, Black and Hispanic dialysis patients experience staph bloodstream infections more frequently than their White counterparts.
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Social and Economic Factors - Social and economic factors contributing to differences in end-stage kidney disease treatment include inadequate prevention and care of kidney disease, socioeconomic and insurance status, and insufficient patient education about treatment options.
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Catheter Use - The type of vascular access is the primary risk factor for bloodstream infections, regardless of race, ethnicity, or socioeconomic status. There are three types of access: fistula, graft, and central venous catheter. While infections can occur with any type of access, fistulas have the lowest infection risk, whereas central venous catheters have the highest.
Conclusion
Avoiding catheter use is the best strategy to reduce bloodstream infections. Effective interventions include early referral to nephrologists, using multidisciplinary teams, and having vascular access coordinators educate patients. Early-cannulation arteriovenous grafts for hemodialysis and urgent-start peritoneal dialysis can also decrease catheter use; a comprehensive approach to infection prevention is crucial for patients who must use a catheter.
This involves active patient involvement, staff education on proper catheter care, and strict adherence to the CDC’s core interventions. Utilizing electronic checklists and audit tools for catheter care may enhance antiseptic techniques and patient education in dialysis units.
New strategies for preventing catheter-associated bloodstream infections include chlorhexidine-impregnated transparent exit-site dressings, chlorhexidine-coated rod hub devices, and non-antibiotic antimicrobial locks.
