Peritoneal catheter exit-site and tunnel infections in peritoneal dialysis in adults

INTRODUCTION — Peritoneal dialysis requires the placement and maintenance of a catheter that transverses the patient's abdominal wall and extends from the outer abdominal surface into the peritoneal cavity. The catheter exit site, tunnel, and peritoneum are prone to bacterial infection, which can cause morbidity and result in catheter removal.

This topic reviews the prevention, evaluation, and treatment of catheter-related infections including exit-site infections (ESIs) with or without tunnel infections. The microbiology and treatment of peritonitis and diagnosis of peritonitis in peritoneal dialysis patients are discussed elsewhere. (See "Microbiology and therapy of peritonitis in peritoneal dialysis" and "Fungal peritonitis in peritoneal dialysis" and "Clinical manifestations and diagnosis of peritonitis in peritoneal dialysis".)

PATHOGENESIS — The catheter and exit site become colonized with bacteria soon after catheter placement. Bacteria secrete a biofilm, which encourages further bacterial growth and protects the colonizing organisms from antibodies, white blood cells, and antimicrobial agents.

Colonization predisposes to infection, which can occur following mild exit-site trauma. The infection may involve the exit site alone or the exit site and tunnel in which the catheter resides. A tunnel infection usually occurs only in the presence of an exit-site infection (ESI) [1].

Most exit site with or without tunnel infections are caused by gram-positive bacteria, usually Staphylococcus species [2-7]. Gram-negative organisms (Pseudomonas aeruginosa and Escherichia coli) cause the majority of the remainder [2-7].

EPIDEMIOLOGY AND MICROBIOLOGY — Exit-site infections (ESIs) have decreased since clinicians started using antimicrobial prophylaxis and other preventive measures [2,8-10]. Since daily topical antibiotic cream for infection prophylaxis became the standard of care, the reported rate of ESIs is approximately 12/100 patient-years [11]. (See 'Prevention' below.)

Risk factors associated with development of ESI include [12-14]:  

●Poor competency of exit-site care

●Catheter mobilization

●Catheter pulling-out injury

●Mechanical compression of the catheter by a waist belt

●Swimming

●Presence of pets during exchanges

●Compression of the exit site by a peritoneal dialysis catheter bag (used in some countries)

Demographic factors such as age, sex, and race, and clinical factors such as diabetes or insulin dependence are not predictive of ESI [6,15].

The causative agents have also changed with routine antibiotic prophylaxis. Although most infections are still caused by gram-positive organisms, the percentage caused by Staphylococcus aureus appears to have decreased with relative increases in other gram-positive organisms and gram-negative organisms [2-7]. In one study in which prophylactic topical gentamicin was used at the exit site, ESI was caused by S. aureus in 33 percent, other gram-positive organisms in 27 percent, and gram-negative organisms in 7 percent [6]. A sterile culture was obtained in 13 percent.

In addition, several studies have reported infection caused by uncommon organisms such as atypical mycobacteria, non-diphtheria Corynebacteria, and Burkholderia cepacia [4-7,16].

The relative proportion of fungal infections has increased with prophylactic antibiotics, although the frequency has not, which reflects the overall decrease in bacterial infections [3,11]. In the study cited above in which prophylactic topical gentamicin was used at the exit site, 20 percent of ESIs were caused by yeast [6].

The selection of the topical antimicrobial agent used for prophylaxis may alter the epidemiology of causative organisms. In a trial comparing mupirocin and gentamicin prophylaxis, 9 of 15 infections in the gentamicin group were from gram-positive organisms, and only one was from a gram-negative organism, whereas, in the mupirocin group, 17 of 29 were from gram-positive organisms and 9 of 29 were from gram-negative organisms [6]. In another study of 147 patients on peritoneal dialysis who received mupirocin prophylaxis for seven years, 11 percent of patients were S. aureus carriers, and 25 percent of these (representing 2.7 percent of the patient population) had mupirocin-resistant S. aureus [17].

PREVENTION — The risk of exit-site and tunnel infection is decreased by preventive measures instituted prior to and immediately after catheter placement, as well as throughout the life of the catheter [18]. The following measures are largely consistent with the International Society for Peritoneal Dialysis (ISPD) published guidelines [1,19].

Prior to catheter placement — We administer systemic antibiotics immediately prior to surgery. The 2017 Kidney Disease: Improving Global Outcomes (KDIGO) and ISPD guidelines recommend screening and treating patients for S. aureus nasal carriage prior to peritoneal dialysis catheter insertion. However, we do not routinely test for S. aureus carriage because patient adherence to treatment of it is often suboptimal and because routine exit-site care includes the application of either gentamicin or mupirocin cream, which treat S. aureus [1,20]. Specific recommendations for systemic antibiotics are discussed elsewhere. (See "Placement of the peritoneal dialysis catheter".)

Immediately after surgery — After placement of the catheter, the incision should be covered and the dressing left undisturbed for five to seven days. Any dressing changes required during this time should be done by a peritoneal dialysis nurse rather than the patient. The site should be kept dry, which precludes taking showers for at least three weeks [21].

Maintenance preventive care — Routine maintenance measures to prevent infection include daily or every-other-day washing of the exit site and topical antimicrobial agents.

Washing and general care of the exit site — Once the exit site is healed, it should be washed daily or every other day with antibacterial soap or an antiseptic. Povidone iodine solution (10%) and chlorhexidine solution (0.05 to 2%) have been shown to reduce the incidence of exit-site infection (ESI) compared with soap and water [1,22,23]. Hydrogen peroxide should not be used, since it tends to dry out the site and may be toxic to the normal granulation tissue.

When cleaning the exit site, crusts, if present, should not be forcibly removed. The exit should be dabbed dry after cleaning using a clean cloth or towel. We, and most other nephrologists, use a nonocclusive dressing (such as gauze) to cover the exit site, although one study suggests that a dressing may not be necessary [24].

We suggest that patients immobilize the catheter with tape to prevent accidental injury to the exit site, although there are no data that specifically support this practice [12].

Antimicrobial prophylaxis

Daily topical antibiotics at exit site — We prescribe a daily topical antimicrobial agent in addition to measures defined above [1]. (See 'Washing and general care of the exit site' above.)

Topical antibiotics decrease the risk of ESIs and peritonitis [8,25-31]. We suggest daily application of a topical antibiotic. Daily, compared with less frequent, application of topical antibiotics was associated with fewer ESIs and a lower level of antimicrobial resistance [17,32-34].

Two commonly used topical antibiotics are mupirocin and gentamicin. Some experts prefer mupirocin while others use 0.1 percent topical gentamicin sulfate. Some peritoneal dialysis centers alternate between mupirocin and gentamicin by the month. Each approach is reasonable. Gentamicin is as effective as mupirocin against S. aureus and other gram-positive organisms and may be more effective against gram-negative organisms [6,35-37]. Gentamicin is generally less expensive than mupirocin.

Many other topical and oral antimicrobial agents, including Medihoney, have been studied but are generally considered experimental or unproven [7,30,38-49].

Topical nasal antibiotics — We do not use nasal antimicrobial agents for maintenance prophylaxis. Application of nasal antimicrobial agents is uncomfortable and of limited clinical benefit. In one trial of 267 patients, nasal application of mupirocin was associated with reduced incidence of ESI due to S. aureus (14 versus 44 infections over 18 months); however, the rates of peritonitis and all ESI were similar (33 per 1390 versus 55 per 1236 patient-months) [20,50,51].

Oral antibiotics following catheter trauma — We administer systemic oral antibiotics to all patients who report trauma to their exit site, although there are no data that specifically support this approach.

We give cephalexin for three days (table 1). If the patient is allergic to cephalosporins, we give ciprofloxacin for three days (table 1).

Granulomas may occasionally occur at the exit site. A trained nurse can apply silver nitrate to the granuloma on one occasion for cauterization. Another option is for the patient to apply chlorhexidine daily. In a randomized trial of 44 patients with exit-site granulomas, rates of healing were similar between chlorhexidine and silver nitrate (94 versus 100 percent, respectively) [52]. There was less pain associated with chlorhexidine application.

Environment and lifestyle — A clean environment and certain lifestyle changes may help reduce the rate of exit-site and tunnel infections, as suggested by observational data looking at environmental exposures [53,54].

Peritoneal dialysis patients are generally discouraged from taking baths, using hot tubs, or swimming in rivers, lakes, or the ocean. Swimming in swimming pools and salt water bodies may be safer, but not completely without risk of ESI and peritonitis [13]. In a cross-sectional survey of 39 Australian peritoneal dialysis units where swimming among patients was near-universal, seven episodes of ESI and two of peritonitis were attributed to swimming [13].

However, when patients choose to swim or take a bath, we advise them to cover the catheter and exit site with an ostomy bag and to immobilize the catheter (ie, with tape). We instruct patients to do their daily exit-site care after swimming or bathing in a tub.

Pets in the house may increase the risk of infection, although zoonotic bacteria account for a low percentage of peritonitis episodes (0.03 to 0.54 percent) [55]. Although we generally do not actively discourage patients from having pets, we advise that pets remain out of the room when exchanges are performed.

ROUTINE MONITORING — The exit site should be examined daily by the patient and monthly by a clinician or the home unit medical staff in order to detect infection as early as possible. In addition, the exit site should be examined by a clinician whenever the patient detects a change in the appearance of the exit site.

Examination of the exit site begins with gross visual inspection. Some clinicians use a magnifying glass for closer observation, though we do not. The catheter tract should be milked to see if any drainage is present and observed for evidence of erythema overlying the tunnel, which is the part of the catheter between the two cuffs. Some clinicians routinely grade the exit during these monthly visits according to grading systems that have been developed for adult (table 2A-B) [56] and pediatric patients (table 3) [57].

We maintain a photographic record of the exit site (ie, using a mobile phone) so that accurate comparisons between visits are possible [1].

CLINICAL PRESENTATION AND EVALUATION — Any change from the patient's normal, healthy exit site may be a sign of a new exit-site infection (ESI) (table 2A-B).

Exit-site infection — Typically, infection presents initially as increased crust formation and/or erythema surrounding the exit site and progresses to serous and purulent drainage arising from the exit site. Patients generally do not have fever or chills in the early stages of infection.

While any change from the patient's normal, healthy exit site may be a sign of a new ESI (table 2A-B), changes limited to mild erythema, skin induration, or increased crust formation may alternatively reflect mild trauma involving the catheter or an allergic reaction [57,58].

We carefully examine the exit site and catheter tract. We milk the catheter tract to express drainage. Any drainage should be sent for Gram stain and culture to direct antibiotic therapy. Culture of the site is not helpful if drainage is not present, since, in the absence of discharge, positive cultures may just represent colonization. (See 'Treatment' below.)

Tunnel involvement — Tunnel involvement manifests as erythema, edema, induration, or tenderness over the catheter pathway [1]. If untreated, infection may progress to abscess formation within the tunnel. Tunnel abscess is more likely with infections caused by S. aureus or P. aeruginosa.

We obtain an ultrasound of the catheter tract only if we suspect a tunnel abscess based on symptoms and physical examination (such as marked tenderness over the catheter pathway and drainage from the site after milking the tract) or if ESI is resistant to treatment. Ultrasound is effective in revealing fluid collections [59]. (See 'Resistant infection' below.)

DIAGNOSIS — We diagnose exit-site infection (ESI) if there is purulent discharge from the exit site, with or without erythema, or if there is severe acute erythema without purulent discharge that develops in the absence of acute trauma to the catheter [1,60].

We diagnose tunnel infection if there is erythema, edema, induration, or tenderness over the catheter pathway.

Even in the absence of drainage or severe erythema, any change in appearance of the exit raises the suspicion of infection, but we do not diagnose ESI, at least initially, among patients who present with only mild erythema, skin induration, or increased crust formation, since these changes alone may not represent an infection [57,58].

Erythema without infection is commonly observed following placement of the catheter or after mild trauma involving the catheter [61]. Skin erythema may also be a manifestation of an allergic reaction [61].

Patients with mild erythema, skin duration, or crust formation are closely followed for progression of local changes. We ask patients to examine the exit site daily and report any increase in erythema or crust formation or the development of discharge. The exit site should be evaluated by the clinician or home unit medical staff in one week. Serial photographs may be helpful to assess progression or improvement. It is important during this time to make sure that the patient is adhering to optimal catheter hygiene and preventive care. (See 'Maintenance preventive care' above.)

TREATMENT — We agree with the 2017 International Society for Peritoneal Dialysis (ISPD) guidelines that all exit-site infections (ESIs) with or without tunnel involvement should be treated with antibiotics [1,19]. The initial treatment of exit-site and tunnel infections is the same.

Untreated ESIs commonly lead to peritonitis [62]. In one retrospective study, over 30 percent of all cases of peritonitis associated with catheter infection were preceded by an exit site or tunnel infection [62]. Antibiotics are effective in treating ESIs.

Empiric therapy — We agree with the 2017 ISPD infections guidelines that empiric antibiotic therapy should be initiated based on Gram stain (algorithm 1) [1]:

●Gram-positive organism – A first-generation oral cephalosporin (such as cephalexin) or a penicillinase-resistant penicillin (such as dicloxacillin). We use clindamycin if the patient is allergic to penicillin (table 1).

●Gram-negative organism – Ciprofloxacin (table 1). If the patient cannot take ciprofloxacin, we use intraperitoneal ceftazidime. Ceftazidime may be given continuously (500 mg/L loading dose followed by 125 mg/L in all subsequent exchanges) or intermittently (1000 to 1500 mg in one exchange daily). For intermittent dosing of intraperitoneal antibiotics, the dwell time should be at least six hours to allow adequate absorption [1].

●Gram stain results unavailable or inconclusive – Both a first-generation oral cephalosporin or a penicillinase-resistant penicillin and ciprofloxacin (table 1). We use clindamycin if the patient is allergic to penicillin (table 1). If the patient cannot take ciprofloxacin, we use intraperitoneal ceftazidime as described above for gram-negative organisms [1].

There are two exceptions to the approach defined above.

●The patient who has had prior infection or colonization with methicillin-resistant S. aureus (MRSA) and Gram stain showing gram-positive organisms should receive empiric treatment for MRSA. We use oral cephalexin or ciprofloxacin for broad-spectrum coverage and also give intraperitoneal vancomycin (15 to 30 mg/kg every five to seven days) to cover possible MRSA. Serum vancomycin levels should be checked prior to redosing to assure that a therapeutic level (goal 15 to 20 microgram/mL) is achieved, particularly among patients with residual kidney function, who may require a higher maintenance dose or more frequent dosing. For intermittent dosing of intraperitoneal antibiotics, the dwell time should be at least six hours to allow adequate absorption [1].

●The patient who has had prior infection or colonization with Pseudomonas and Gram stain showing gram-negative organisms should receive an antipseudomonal antibiotic. We usually use ciprofloxacin monotherapy, as we do for all gram-negative organisms, but we treat for three weeks rather than two weeks, which is standard duration for other organisms [56]. If the patient cannot take ciprofloxacin, we use intraperitoneal ceftazidime as described above for gram-negative organisms [1].

Some clinicians treat potential Pseudomonas infections with two-drug therapy such as oral ciprofloxacin and with an intraperitoneal aminoglycoside (preferably amikacin [2 mg/kg in one exchange per day] or tobramycin [0.6 mg/kg in one exchange per day]) or intraperitoneal ceftazidime (using dose defined above). Continuous dosing (ie, adding antibiotic to each exchange) is not recommended for aminoglycosides. Pseudomonas infections are more likely to be associated with the development of antibiotic resistance with monotherapy [1].

Occasionally, empiric therapy may need to be based on local patterns of infection and trends in antibiotic resistance, although generally this does not overly influence the choice of initial antibiotic [6]. Vancomycin should not be used in routine therapy, since there is a high incidence of vancomycin-resistant organisms.

Treatment duration and follow-up — Antibiotic therapy is adjusted depending on culture and sensitivity results. In addition, we re-evaluate clinically after one week.

If the patient is improving, we continue antibiotics until the infection is completely resolved and for a minimum of two weeks for all organisms except Pseudomonas. If the patient has a Pseudomonas infection, we treat for a minimum of three weeks.

If the patient is not improving at the one-week evaluation, our approach depends on the culture and sensitivity results. If the organism is a Staphylococcus species and there is no improvement after one week, then oral rifampin should be added to the regimen. Rifampin has good tissue penetration and acts synergistically with antistaphylococcal penicillins and vancomycin. Rifampin should not be given as single-agent therapy (table 1) [57,58].

If the organism is a Pseudomonas species and the patient has not responded by one week, a second antipseudomonal drug, such as intraperitoneal ceftazidime (dosed continuously [500 mg/L loading dose followed by 125 mg/L in all subsequent exchanges] or intermittently [1000 to 1500 mg in one exchange daily]) or intraperitoneal aminoglycoside (such as amikacin, 2 mg/kg in one exchange per day, or tobramycin, 0.6 mg/kg in one exchange per day). Intraperitoneal aminoglycosides should be given intermittently rather than continuously. For intermittent dosing of intraperitoneal antibiotics, the dwell time should be at least six hours to allow adequate absorption [1].

Other antipseudomonal drugs, such as cefepime, piperacillin, imipenem, or meropenem, may also be used with ciprofloxacin [56-58].

For all other organisms, we rely on the sensitivities to direct antibiotics. The culture may be repeated at this point if initial results are considered unreliable. In addition, assess compliance with the regimen.

If appropriate antibiotic therapy has no effect on the infection after two weeks, the exit-site/tunnel infection is considered resistant. Surgical interventions are often indicated at this point [58]. (See 'Resistant infection' below.)

However, if at least some improvement is observed, we will continue antibiotic treatment for up to six weeks before surgical intervention. Patients who receive prolonged antibiotics should also receive antifungal prophylaxis. (See 'Antifungal prophylaxis' below.)

Fungal infections — Fungal infections are a rare cause of ESI, and there are little published data to direct treatment. It is important to ascertain that the fungus identified in the culture is not a contaminant. Repeat culture or demonstrating the absence of other micro-organisms will help to confirm this. The catheter should usually be removed if there is definite fungal ESI to prevent progression to fungal peritonitis. (See 'Catheter removal and replacement' below.)

Antifungal prophylaxis — Our approach towards antifungal prophylaxis, choice of agent, and dosing among patients on peritoneal dialysis are discussed elsewhere. (See "Fungal peritonitis in peritoneal dialysis", section on 'Prevention' and "Microbiology and therapy of peritonitis in peritoneal dialysis", section on 'Role of antifungal prophylaxis'.)

Resistant infection — Resistant infection is defined by persistent clinical findings despite optimal antibiotics. For all patients with resistant infection, we make certain that they are adherent to the therapeutic regimen, and also perform an ultrasound to help identify a fluid collection in the tunnel. For patients whose external cuff is not exposed and there is no evidence of abscess or tunnel infection, we treat with another week of antibiotic therapy. For patients whose external cuff is exposed, or if a fluid collection is observed, we refer them to a qualified clinician (eg, surgeon) to remove the external cuff of the catheter. Alternatively, these patients who have the cuff exposed can undergo simultaneous catheter removal and replacement. For patients whose peritoneal catheter or tunnel infection is due to a fungus, we refer them directly for catheter removal. (See 'Catheter removal and replacement' below.)

A thorough repeat examination should be performed for all patients with a resistant infection. We also perform an ultrasound to help identify a fluid collection in the tunnel [63]. When obtaining an ultrasound, it is important to specify that the catheter tract is the suspected site of infection so that the ultrasound gain is adjusted accordingly. In one study, ultrasonography revealed findings suggestive of abnormal fluid collections in 21 of 22 cases of ESI with tunnel infection (but also in 4 of 20 controls without an ESI) [59]. Computed tomography (CT) scanning or gallium scanning may be alternatives to ultrasound.

Movement of the exposed cuff in and out of the exit site may cause local trauma, thereby disrupting healthy granulation tissue and causing persistent infection. In addition, bacteria may be adherent to the cuff, resulting in resistance to antibiotics. Thus, if the external cuff is exposed, or if a fluid collection is observed, we remove the external cuff of the catheter to improve drainage. If the external cuff is not exposed and there is no evidence of abscess or tunnel infection, then another week of therapy may be helpful.

Removal of the external cuff is typically performed under sterile conditions and local anesthesia either at the patient's bedside or in an outpatient office [64]. The techniques used vary depending upon the clinician's preference and experience. As examples, cuffs can be teased away from the catheter using blunt forceps [65]. Another method of cuff removal is called "cuff shaving." While some clinicians use scalpels for cuff shaving, others prefer to use abrasives such as sandpaper, emery boards, or bovine scrapers to remove the cuff, which have a much lower risk of damage to the catheter compared with scalpels. Because cuff shaving can damage the catheter, it needs to be performed by a clinician experienced with the technique [66]. If the cuff is only partially exposed, the tunnel may need to be deroofed for complete exposure and removal.

Conflicting results have been observed with the cuff-shaving procedure [2,65,67-69]. In some studies, cuff shaving was effective for resistant ESIs [66,68,69]. In one study, for example, 48 patients underwent 53 cuff-shaving procedures [66]. Among these patients, 34 percent of the infections were due to S. aureus, 17 percent due to Corynebacterium spp, 15 percent due to P. aeruginosa, and 8 percent due to fungal agents. Cuff shaving was associated with resolution of 39 of the 53 infections (74 percent), with the remaining patients requiring catheter removal due to persistent infection or leak.

After a total of three weeks of antibiotics, if there is still no improvement, the patient should have the catheter removed. (See 'Catheter removal and replacement' below.)

An alternative to cuff shaving is relocation of the exit site with removal of the external cuff, which can also be performed as a day procedure under local anesthesia. One retrospective study from the United Kingdom analyzed outcomes of 27 patients with a resistant ESI (mostly Pseudomonas and S. aureus infections) who were treated with exit-site relocation and cuff removal [70]. Patients were permitted to resume peritoneal dialysis immediately following the procedure, and oral antibiotics were continued for two to four weeks until healthy granulation tissue was observed. At a follow-up of four years (range 11 to 79 months), most patients (74 percent) had long-term resolution of infection; seven required catheter removal due to recurrent ESI (n = 5) or tunnel infection (n = 2). While these findings are encouraging, the independent benefit of the procedure is difficult to assess given the lack of a control group and the administration of cointerventions, including cuff removal and additional antibiotic therapy.

Other observational studies have also found benefit with relocation of the exit site. In one study of 52 patients with intractable exit-site or tunnel infections who underwent cuff shaving and creation of a new tunnel, infection-free catheter survival at 6 and 12 months was 57 and 35 percent, respectively [71]. Another study that evaluated 40 catheter diversion procedures among 33 patients with exit-site or tunnel infection found the infection-free rate was 90 percent at 30 days and 67 percent at 90 days [72]. Importantly, the median peritoneal dialysis catheter survival was 84 months, and patients undergoing catheter diversion had longer catheter survival and were more likely to stay on peritoneal dialysis than patients who had their catheters removed and replaced.

Catheter removal and replacement — Catheter removal is required for some exit-site and tunnel infections. The following are indications for catheter removal [1]:

●Exit-site or tunnel infection occurring simultaneously with or progressing to peritonitis during antibiotic treatment.

●The exit-site or tunnel infection is resistant to antibiotics. A resistant infection is defined as one that shows no improvement after three weeks of appropriate antibiotics with/or without cuff shaving or has not completely resolved after six weeks.

●The exit-site or tunnel infection is caused by fungus. (See 'Fungal infections' above.)

In all cases, perioperative antibiotics should be given [57] and then continued for one to two weeks after catheter removal.

The catheter should be removed by surgical dissection rather than by traction. Removal by traction may result in retention of the peritoneal and/or subcutaneous cuffs, which could lead to local infection or sepsis. In one study, a change in removal practice from traction to surgical dissection resulted in a significant reduction in the incidence of local infections (0 versus 24 percent) [73].

If there is no peritonitis associated with the ESI, the infected catheter can be removed and a new catheter placed simultaneously in the opposite lower quadrant [74]. The "clean" step of inserting the new catheter on the opposite side of the abdomen is performed before the "dirty" step of removing the old catheter, with care to avoid cross-contamination of wounds. This procedure is commonly performed in the pediatric population and has also been shown to be effective in adults [75,76]. In one study, simultaneous catheter placement and removal was successful in 30 of 36 patients [75]. In the remaining six, persistent infection developed in two, and the procedure was not successful for technical reasons in four.

A new catheter should not be placed at the time the infected catheter is removed if active peritonitis is present. We wait at least two weeks after catheter removal and complete resolution of peritoneal symptoms before placing a new catheter. This practice is consistent with the 2017 update of the ISPD catheter-related infection recommendations [1]. However, simultaneous catheter removal and replacement can be performed for relapsing peritonitis caused by the Staphylococcus species if antibiotic therapy resolves abdominal symptoms and the peritoneal fluid cell count is <100/microL. This practice is consistent with the 2019 ISPD guidelines on creating and maintaining the peritoneal dialysis catheter [77]. (See "Microbiology and therapy of peritonitis in peritoneal dialysis".)

PROGNOSIS — Most exit-site infections (ESIs) resolve with appropriate treatment. However, some infections do not resolve. Catheter infections with Pseudomonas are particularly problematic, with lack of response to treatment in approximately 50 percent of cases [60]. In a series of 14 patients with Pseudomonas ESI treated with oral and intraperitoneal antibiotics, only six patients had a cure with no recurrence [78].

If the ESI is not treated or does not respond to treatment, two major complications may result, including peritonitis and removal of the catheter.

Peritonitis is the most serious complication [62]. Patients who develop an ESI are much more likely to develop peritonitis, even if the ESI was appropriately treated [79].

Peritonitis most commonly results from S. aureus or P. aeruginosa-related ESIs with tunnel infections. In the study cited above, among 14 patients with Pseudomonas ESI, two patients had Pseudomonas peritonitis at presentation, and four developed Pseudomonas peritonitis [78].

Resistant ESIs may also result in removal of the catheter, requiring the temporary or permanent switch from peritoneal dialysis to hemodialysis [62]. In the study above, of 14 patients, the catheter was removed in four patients because of peritonitis and in three patients because of the severity or recurrence of the ESI [78]. (See "Microbiology and therapy of peritonitis in peritoneal dialysis", section on 'Prognosis'.)

ESIs are rarely a direct cause of mortality unless they are untreated and progress to bacterial or fungal peritonitis.

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Beyond the Basics topic (see "Patient education: Peritoneal dialysis (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Microbiology – Peritoneal dialysis requires the placement and maintenance of a catheter in the peritoneal cavity. The exit site and catheter tunnel are prone to bacterial infection. More than 50 percent of infections are caused by gram-positive organisms, with Pseudomonas aeruginosa and Escherichia coli causing the majority of the remainder. (See 'Introduction' above and 'Pathogenesis' above.)

●Prevention – Exit-site and tunnel infections are decreased by preventive measures. In addition to washing the exit site daily, we recommend application of topical antibiotics versus no antibiotics (Grade 1B). Multiple studies have shown that topical antibiotics reduce the risk of exit-site infections (ESIs). We use 0.1% topical gentamicin sulfate administered daily; mupirocin is also effective. (See 'Antimicrobial prophylaxis' above.)

Preventive systemic antibiotics are also given prior to catheter placement and following any inadvertent trauma to the catheter. (See 'Prior to catheter placement' above and "Placement of the peritoneal dialysis catheter" and 'Oral antibiotics following catheter trauma' above.)

●Clinical presentation and evaluation – The exit site should be examined daily by the patient and at least monthly by a clinician and whenever the patient detects a change in the appearance of the exit site. The clinical presentation of exit-site or tunnel infection is described above. (See 'Clinical presentation and evaluation' above.)

●Empiric therapy – We treat all patients with exit-site and/or tunnel infections with systemic antibiotics. Antibiotics are effective in treating most ESIs. Our approach to patients is defined above. (See 'Empiric therapy' above.)

●Catheter removal and replacement – The catheter should be removed if the exit-site or tunnel infection occurs simultaneously with or progresses to peritonitis. Catheter removal or exit-site diversion should be performed for exit-site or tunnel infection that shows no improvement after three weeks of appropriate antibiotics with or without cuff shaving, or the exit-site or tunnel infection is caused by fungus. (See 'Catheter removal and replacement' above.)