Dialysis is a life-sustaining treatment for individuals whose kidneys can no longer effectively filter waste and excess fluid from the blood. This process, delivered through hemodialysis (HD) or peritoneal dialysis (PD), requires a physical connection to the body. These access points, whether tubes or surgically altered blood vessels, create a gateway for infection. Dialysis access infections are a leading cause of hospitalization and a major contributor to death in this patient population, emphasizing the need for prevention and prompt treatment.
How Dialysis Access Creates Vulnerability
The nature of dialysis requires repeated or constant entry into the body, bypassing the natural protective barrier of the skin. Hemodialysis requires vascular access, while peritoneal dialysis relies on an abdominal catheter, and each type presents distinct infection risks. The most common bacteria involved in these infections are staphylococcal organisms, which are typically found on the skin.
Central Venous Catheters (CVCs)
CVCs carry the highest risk for severe bloodstream infections among all access types. They provide a direct, indwelling conduit into the central circulation, inserted into a large vein, often in the neck or chest. Bacteria can travel along the external surface of the catheter from the skin. They can also enter through the internal hub when the line is connected or disconnected for treatment.
Arteriovenous (AV) Fistulas and Grafts
Arteriovenous fistulas, created by surgically connecting an artery and a vein, are the preferred access method due to their lower infection rate. They still risk localized skin or soft tissue infection, such as cellulitis, especially at the site of repeated needle sticks. Grafts use a synthetic tube to connect the artery and vein and have an intermediate risk of infection. The foreign material in grafts can serve as a surface for bacteria to colonize, making infections difficult to clear and often requiring removal of the synthetic material.
Peritoneal Dialysis (PD) Catheters
Peritoneal dialysis uses a catheter placed into the abdominal cavity to cycle cleaning fluid. The specific infection risk is the development of peritonitis, an infection of the peritoneal lining. This occurs when bacteria enter the abdominal cavity through the catheter tunnel or the external exit site. Localized infections at the catheter exit site can also occur, which may track down the catheter tunnel and lead to the internal infection.
Identifying Symptoms of Infection
Recognizing the early signs of infection is important for initiating timely treatment and preventing complications like sepsis. Infections related to dialysis access can manifest as localized problems at the access site or as widespread systemic illness. Patients and caregivers should perform daily checks and understand which symptoms require immediate medical attention.
Localized Access Site Symptoms (HD)
For fistulas, grafts, and central venous catheter exit sites, localized signs of infection involve changes to the surrounding skin. Symptoms include new or increasing redness, tenderness or pain upon touching the site, and swelling or warmth. The presence of purulent discharge, or pus, draining from the access site or needle insertion points indicates a localized infection. Any red streaking extending away from the access site may indicate a spreading infection and requires urgent evaluation.
Systemic Symptoms (General)
Systemic infections occur when bacteria have entered the bloodstream, presenting with symptoms that affect the entire body. The most common signs are fever and chills, sometimes accompanied by rigors, or severe shaking. Other generalized signs suggesting a serious bloodstream infection include unusual fatigue, general malaise, or confusion. A rapid heartbeat or low blood pressure can also indicate a developing infection progressing toward sepsis.
Symptoms Specific to Peritonitis (PD)
Peritonitis presents with symptoms distinct from hemodialysis access infections because the infection occurs inside the abdomen. The most telling sign is cloudy effluent, which is the dialysate fluid drained from the abdomen during an exchange. Patients may also experience abdominal pain, tenderness, or a swollen abdomen. Nausea, vomiting, and loss of appetite can also accompany a peritonitis episode.
Essential Prevention Strategies
Proactive prevention is the most effective way to protect the dialysis access and minimize infection risk. Since the majority of infections are caused by skin-dwelling organisms, meticulous care during any manipulation of the access site is paramount. This responsibility falls on the patient, caregivers, and all members of the healthcare team.
Hand Hygiene and Aseptic Technique
Proper hand hygiene is the most important step in preventing the transfer of bacteria to the access site. Hands must be thoroughly washed with soap and water or an alcohol-based hand sanitizer before touching the access or related equipment. During any connection or disconnection procedure, strict aseptic technique must be followed, involving sterile gloves, masks, and materials. Staff and patients may be required to wear masks when a central venous catheter is accessed or a dressing is changed to prevent airborne contamination.
Catheter Care and Dressing Changes
For patients with central venous or peritoneal dialysis catheters, the exit site must be kept clean and dry at all times. The dressing should only be changed by trained personnel using sterile technique, and the skin is typically cleaned with an antiseptic solution like chlorhexidine. Patients must avoid getting the site wet while bathing. Any dressing that becomes wet, soiled, or loose must be promptly replaced to maintain the protective barrier and prevent bacteria introduction.
Patient Education and Monitoring
Patients must be educated on how to inspect their access site daily for any changes, such as new pain, redness, or swelling. For fistulas and grafts, patients should wash the access area with soap and water daily and immediately before a dialysis session. They should also be instructed to avoid scratching, picking, or applying unnecessary pressure to the access site. Any signs of trouble must be reported to the care team right away, as early reporting improves the chances of successful treatment.
Antibiotic Prophylaxis
Antibiotics are sometimes used to prevent infection in specific, high-risk situations, rather than routinely. An antibiotic lock solution, a concentrated antibiotic mixture instilled into the catheter lumen when not in use, can reduce the risk of catheter-related bloodstream infections. Prophylactic antibiotics may also be prescribed before certain dental procedures or surgeries to prevent bacteria from entering the bloodstream and traveling to the access site.
Treating Infections and Protecting Future Access
Once an infection is confirmed, medical teams must act quickly to eradicate the bacteria while attempting to preserve the patient’s long-term access options. This involves balancing aggressive infection treatment with the need to maintain a functional connection for ongoing dialysis.
Standard Treatment Protocols
The first step in treating an infection is drawing blood and access site cultures to identify the specific bacteria causing the illness. While awaiting results, doctors usually begin treatment with broad-spectrum antibiotics, often administered intravenously, covering common organisms like Staphylococcus aureus. The antibiotic regimen is then narrowed once culture and sensitivity results are available, with treatment generally lasting seven to fourteen days. For certain catheter infections, an antibiotic lock solution may be used in combination with systemic antibiotics to help clear the infection from inside the catheter.
Access Preservation vs. Removal
The decision to preserve or remove the infected access depends on the type of access, the severity of the infection, and the type of bacteria identified. Catheters are frequently removed if the infection is severe, the patient is seriously ill, or the bacteria is aggressive, such as Staphylococcus aureus or Pseudomonas aeruginosa. Infected grafts often require surgical removal of the foreign material to fully clear the infection. Preserving a fistula is generally attempted more often because of its lower risk and superior long-term function.
Consequences of Severe Infection
A severe, untreated dialysis access infection can quickly lead to sepsis, a life-threatening response that requires immediate hospitalization. Sepsis carries a high risk of death, especially in dialysis patients whose immune systems are compromised. If an infected access must be removed, the patient will need a new access created. This loss limits future options for long-term access and may lead to temporary reliance on a suboptimal access type or a change in dialysis modality.