Catheter exit-site infections (ESI) are closely related to peritonitis and remain a significant source of morbidity and technique failure among PD patients. Patients with exit site infections have many more problems with catheter loss (5-10% of ESI result in catheter loss), peritonitis from the same or other organisms and overall PD technique failure1.
There are many factors that could have an impact on exit site infections and catheter loss have been described in the literature. These include the type of catheter used, exit site and tunnel configuration, PD exchange method or PD modality (Table 1).
Table 1: Potential factors influencing ESI and catheter loss
|
Potential Factors |
Evidence |
|
Type of catheter |
|
|
|
Not available |
- Swan-neck vs Cruz vs Moncrief vs straight
|
Not available |
|
Exit and tunnel configuration |
|
|
|
+ |
|
|
Not available |
- Downward orientation of exit-site and external catheter
|
++ |
|
PD exchange method (standard vs disconnect systems) |
+++ |
|
PD modality (CAPD vs APD) |
++ |
|
|
|
|
|
There is no evidence that the type of catheter used has any influence on exit-site infections. Several types of catheters have been designed to optimize the configuration of the subcutaneous tunnel, but the data do not support an advantage of one type over another and the results vary more with the operators experience than with the type of catheter used. Therefore, no specific configuration can be recommended and standard double-cuff catheters remain the most commonly used.
It is important to create a tunnel deep enough and away from the dermis to avoid superficial erosion of the external cuff. Common practice is to place the external cuff 1-2 cm from the skin opening. There is no evidence to suggest that the length of the tunnel has any impact on the incidence of ESI. A downward orientation of the catheter exit was first recommended by Tenckhoff and is the general practice of most practitioners2. Although there are no randomized studies to show the superiority of this method over a cephalad orientation, the general opinion is that it reduces exit site infections by facilitating drainage.
The use of disconnect systems have markedly reduced infectious complications of PD including ESI. Similarly, APD, being a disconnect system has been known for many years to have fewer ESI than CAPD, perhaps due to the less frequent manipulation of the catheter3.
Other factors may influence the occurrence of exit site infections. Extruding granulation tissue or "proud flesh" can become inflamed at the exit site. If this occurs, it is often treated by simple excision or cauterization. Other primary skin or allergic conditions can also cause local inflammation and complicate exit site care. Materials used in the manufacturing of the catheter may have an impact. The silastic material used in the manufacturing of most catheters can produce mild local inflammation that usually goes away quickly, but the Dacron cuff can cause a foreign body reaction that can last much longer. This local inflammation could leave the exit site and tunnel vulnerable to bacterial growth1.
Exit site care itself can impact complication rates. Recommendations range from the use of soap and water to more vigorous cleansing with an antiseptic agent. Povidone iodine and hydrogen peroxide have been recommended for cleaning the exit postoperatively. However, there is evidence showing that disinfectants, including hydrogen peroxide and povidone iodine are cytotoxic, causing tissue damage and delaying clean wound healing4. In addition, chronic use of povidone iodine can cause chemical burn to the skin.
Early Exit Site Care
Chronic Care of the Healed Exit Site
Diagnosing Exit Site Infections
Causative Organisms
Preventing Exit Site Infections: Prophylaxis
Treatment
References:
- Swartz RD. Exit-site and catheter care: Review of important issues. Adv Perit Dial 15:201-204,1999
- Tenckhoff H, Schechter H. A bacteriologically safe peritoneal access device. Trans Am Soc Artif Intern Organs 14:181-186, 1968
- Holley JL, Bernardini J, Piraino B. Continuous cycling peritoneal dialysis is associated with lower rates of catheter infections than continuous ambulatory peritoneal dialysis. Am J Kidney Dis 16:133-136, 1990
- Lineweaver W, Howard R, Soney D. Topical antimicrobial toxicity. Arch Surg 120:267-270,1985