A five-year study of the microbiologic results of exit site infections and peritonitis in continuous ambulatory peritoneal dialysis

We studied the culture results from 321 continuous ambulatory peritoneal dialysis (CAPD) related infections (exit site, tunnel infections, and peritonitis) in 137 patients over a 5-year period to determine the contribution of exit site and tunnel infections to peritonitis and catheter loss. Seventeen percent of peritonitis episodes were associated temporally and by microbiologic results with exit site or tunnel infections. Twenty-one percent of exit site and tunnel infections and 20% of peritonitis episodes resulted in catheter loss. Peritonitis due to Staphylococcus aureus was more likely to be associated with an exit site or tunnel infection and was more likely to result in loss of the catheter than peritonitis due to Staphylococcus epidermidis. Peritonitis and exit site infections due to Pseudomonas sp also frequently resulted in catheter removal. We found that exit site infections cause significant morbidity in CAPD patients. Further studies in this area are needed.     

Exit-site and tunnel infections in continuous ambulatory peritoneal dialysis patients

One hundred two exit-site infections (ESI) were diagnosed in 63 of 163 (38.6%) patients, with an incidence of one episode every 23.7 patient-months in patients with a history of ESI, whereas in the overall continuous ambulatory peritoneal dialysis (CAPD) population the incidence was one episode every 48.7 patient-months. In diminishing order of frequency, the bacteria isolated were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. The probability of remaining free of ESI was 72% at 1 year and 45% at 5 years. The ESI that led to catheter removal were due to S aureus and gram-negative rods. In 13 (48%) of 27 S aureus ESI unresponsive to antibiotics and local care, deroofing and outer cuff shaving completely resolved the ESI. Despite this treatment, the catheters of the remaining 14 patients had to be removed because of peritonitis associated with the tunnel infection. In conclusion, ESI is a major cause of CAPD failure. In our series, shaving the cuff as a rescue treatment was effective for almost 50% of the patients with antibiotic-resistant S aureus ESI.     

Ultrasonography in the management of exit site infections in peritoneal dialysis patients

AIM: To assess the efficacy of using ultrasonography (USG) in monitoring the progress of exit site infection (ESI) in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: Twenty-two cases of newly diagnosed ESI and 20 cases with normal exit sites as controls were assessed by using USG. The exit sites were reassessed by using USG after finishing a course of antibiotic therapy, and the sonographic findings were correlated with the clinical outcome. RESULTS: Out of the 22 cases of ESI, 21 cases had definite sonolucent zones around the external cuffs, while one case had normal sonographic findings. Of the 20 control cases of normal exit sites, 16 had normal sonographic findings, and four had sonolucent zones around the external cuffs. Exit site infections correlated with positive sonographic findings as compared to normal exits (P <0.0001). The 21 cases of ultrasonic-positive ESI were re-examined after antibiotic therapy, and 10 of these had a post-treatment sonolucent rim around the distal cuff < or =1 mm thick, while 11 cases were persistently > mm thick. The former group was shown to have a more favourable outcome (P=0.013). And despite variable USG findings, all eight patients with Pseudomonas aeruginosa-related ESI had an unfavourable clinical outcome. CONCLUSION: Ultrasonography of the exit sites in CAPD patients is a useful adjunctive tool in the management of ESI. A sonolucent zone around the external cuff >1 mm thick following a course of antibiotic treatment and the involvement of the proximal cuff are associated with poor clinical outcome. In ESI caused by Pseudomonas aeruginosa, the clinical outcome was uniformly poor irrespective of the sonographic findings.     

Leptin in peritoneal dialysate from continuous ambulatory peritoneal dialysis patients.

The adipocyte-derived hormone leptin is the 16-kd product of the ob gene that regulates food intake and body weight. Plasma leptin level is elevated in patients with chronic renal failure, partly because of impaired clearance through the kidney. In this study, we examined whether leptin is cleared into peritoneal dialysate in patients with end-stage renal disease treated by continuous ambulatory peritoneal dialysis (CAPD). The subjects were 46 CAPD patients and 67 age- and gender-matched healthy subjects. Leptin concentration in peritoneal dialysate from CAPD patients was measurable by a sensitive enzyme-linked immunosorbent assay (ELISA), and the daily loss of leptin by the peritoneal route was estimated to correspond to the amount contained in approximately 2 L plasma. Dialysate leptin concentration correlated positively with plasma leptin level and with percent body fat measured by dual-energy X-ray absorptiometry. The dialysate-to-plasma (D/P) ratio of leptin concentration was twice higher than expected from its molecular weight. D/P ratios of beta2-microglobulin, albumin, and transferrin showed strong correlations with each other (r = 0.768 to 0.801), whereas the correlation between D/P ratios of leptin and beta2-microglobulin was less impressive (r = 0.378). This was also the case with the relationship between apparent peritoneal clearances of these macromolecules, suggesting that dialysate leptin had some origins other than passive transport of plasma leptin. To test the hypothesis that abdominal visceral fat may contribute to the unexpectedly raised peritoneal dialysate leptin concentration, multiple regression analysis was performed. Leptin concentration in peritoneal dialysate showed significant association with plasma leptin level and D/P ratio of beta2-microglobulin, and it also showed an independent association with abdominal visceral fat but not with subcutaneous fat assessed by ultrasonography. These results showed that peritoneal dialysate from CAPD patients contained a significant amount of leptin, which derived presumably from both plasma and local visceral fat tissue.     

Emergency laparotomy in patients on continuous ambulatory peritoneal dialysis.

Peritonitis is the most common complication of chronic ambulatory peritoneal dialysis (CAPD). It is often a diagnostic challenge to differentiate those patients with CAPD-associated infections from those who have unrelated gastrointestinal pathology as the cause of peritonitis and would benefit from surgical exploration. A retrospective chart review was performed on all patients at a single institution who were on CAPD between the years 1990 and 1998 and who underwent laparotomy for peritonitis. Six patients underwent laparotomy. Four were male and two were female; ages ranged from 34 to 80 years. Perforated appendicitis was the cause of peritonitis in three patients, perforated diverticulitis was present in two, and one was without any suppurative intra-abdominal process. In each case CT scan of the abdomen was nondiagnostic. There was a delay in diagnosis of 10 days (range 3-21 days) and an operative mortality of 16 per cent.     

Peritoneal tuberculosis in patients receiving continuous ambulatory peritoneal dialysis.

BACKGROUND: Patients with chronic renal failure have an increased risk of tuberculosis (TB). This occurs with much higher frequency within the first 12 months of initiating dialysis and is usually extrapulmonary in nature. Patients most at risk are those from susceptible ethnic groups, especially the Indian subcontinent. Peritoneal TB, otherwise relatively uncommon, has emerged as an important form of TB in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: All cases of peritoneal TB occurring at our institution in patients undergoing CAPD over a 13 year period were identified and analysed. RESULTS: Eight cases were identified, of which seven were non-Caucasian. These patients' characteristics and outcomes are presented. All were undergoing CAPD and most developed TB within 12 months of initiating dialysis. All presented with fever, but symptoms and signs were indistinguishable from bacterial peritonitis. Six were culture-positive, mainly from peritoneal dialysis fluid, but only two cases proved smear-positive. All were treated with standard anti-tuberculous chemotherapy. Three went on to permanent haemodialysis as a result of peritonitis and three have died, one of these as a result of TB. CONCLUSIONS: Peritoneal TB, whilst otherwise relatively uncommon, is an important manifestation of TB in CAPD patients and usually develops soon after commencing dialysis. The reasons for this are unknown and require further research.     

Potassium metabolism in continuous ambulatory peritoneal dialysis patients

Background: Hypokalemia is common and may have contributed to the poor clinical outcome in peritoneal dialysis (PD) patients. In this study, we made a detailed investigation on the potassium metabolism in continuous ambulatory peritoneal dialysis (CAPD) patients and tried to find out the possible factors associated with the high prevalence of hypokalemia in PD patients. Methods: A cross-sectional survey in 243 clinically stable CAPD patients was made in our PD center in 2010. Patients were divided into four groups according to whether they were anuric or not and different dialysis regimens. Patients’ demographic data and data on potassium metabolism including dietary potassium intakes, residual renal potassium, and peritoneal dialysis potassium removal were collected. Results: The average potassium intake in our 243 PD patients was 32.1?±?11.1?mmol/day. The total potassium removal was significantly higher in non-anuric patients as compared to anuric patients (33.2?±?9.1 vs. 23.0?±?4.7?mmol/day for 3 exchanges per day and 35.2?±?8.9 vs. 28.6?±?6.3?mmol/day for 4 exchanges per day, respectively, p?p?p?p?R² linear?=?0.645, p?Conclusions: Our study suggested that if potassium intake was limited in PD patients, we should be aware of the risk of hypokalemia with high doses of PD when patients have good RRF. Our study also suggested that potassium removal in PD patients may not necessarily reflect potassium intake even if serum potassium is normal, the effect of ICW should be considered when evaluating potassium homeostasis.     

Aspergillus peritonitis in continuous ambulatory peritoneal dialysis patients

Aspergillus peritonitis is a rare and serious cause of peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients. We report 3 cases of aspergillus peritonitis in CAPD which were successfully treated by catheter removal and amphotericin. Two of the 3 patients returned temporarily to CAPD, but were subsequently transferred to hemodialysis because of membrane failure. A novel finding in 2 of the 3 cases was a positive Limulus amebocyte lysate test, despite negative bacterial cultures. We discuss the possible relevance of this finding to the diagnosis of aspergillus infections and emphasize the importance of early catheter removal for successful treatment of this condition.     

Successful treatment of Pseudomonas peritonitis during continuous ambulatory peritoneal dialysis

Successful eradication of Pseudomonas peritonitis is described in 12 (57%) of 21 cases from a large continuous ambulatory peritoneal dialysis (CAPD) program at a tertiary care center. In successful cases, cure was achieved within 17 days using therapy which included aminoglycoside started routinely at the onset of symptoms and an antipseudomonal penicillin or cephalosporin derivative added as soon as pseudomonas infection was identified on culture. Of the 9 treatment failures which required catheter removal, 2 had failure of peritoneal drainage, 4 had infection with multiple and/or drug-resistant Pseudomonas strains, and 3 had persistent catheter tunnel infection which resulted in recurrent Pseudomonas peritonitis. Factors such as diabetes mellitus and pediatric age group did not prevent successful medical therapy. Predisposing factors favoring development of Pseudomonas peritonitis included technical failures and in a few cases recent antibiotic therapy. We conclude that Pseudomonas peritonitis complicating CAPD can be successfully cured without catheter removal or discontinuation of CAPD in many cases, particularly when complicating factors are not present.     

Management of bacterial peritonitis and exit‐site infections in continuous ambulatory peritoneal dialysis*

SUMMARY: Peritonitis and exit‐site infections remain the most important limitations to the delivery of continuous ambulatory peritoneal dialysis (CAPD). Contamination of the peritoneum, from endogenous or exogenous sources, is responsible for most peritonitis episodes. Patients usually present with a cloudy bag, although other causes should be distinguished. Clinical suspicion of peritonitis should be followed rapidly by microbiological examination and empirical treatment. Microbiological confirmation allows for subsequent treatment based on sensitivities. Other interventions such as catheter removal may be appropriate in some patients. Exit‐site infections should also be identified and treated early. Peritonitis may be further prevented by adequate exit‐site care, hygienic methods, and techniques to minimise early contamination of the exit site. Mupirocin may also have a role in preventing infections caused by Staphylococcus aureus.     

Eating behavior in continuous ambulatory peritoneal dialysis and hemodialysis patients.

Three groups consisting of 12 subjects each (continuous ambulatory peritoneal dialysis [CAPD] patients, hemodialysis patients, and healthy controls) matched for age, sex, and body weight were invited to a test meal for the study of hunger, fullness, and food preferences. They were served an excess portion of hash served on a plate placed on a hidden scale ("VIKTOR"), which was connected to a computer registering the eating process on-line. The patients filled in visual analogue scales (VAS) concerning appetite and food preferences before and after the test meal. Mean total intake of food (+/- SD) was significantly higher for healthy controls (357 +/- 175 g) compared with hemodialysis patients (295 +/- 105 g), which in turn was higher than in CAPD patients (206 +/- 70 g). Eating velocity was lower in both dialysis groups compared with controls. CAPD patients experienced less hunger and desire to eat compared with hemodialysis patients and controls. The reason for the low eating drive in CAPD patients despite their great need for protein and calories is unknown, but might be explained by gastric retention, insufficient dialysis, metabolic effects of the high sugar load from the dialysate, or combinations of these factors.     

Congestive cardiomyopathy in patients on continuous ambulatory peritoneal dialysis

We present a report of cardiac dilatation and symptomatic congestive heart failure in two patients receiving treatment with continuous ambulatory peritoneal dialysis (CAPD). Both patients had previous partial parathyroidectomies and persistent hypocalcemia prior to the development of a congestive cardiomyopathy. The hypocalcemia was unresponsive to treatment with activated vitamin D therapy; however, intravenous replenishment of the ionized serum calcium level was accompanied by improvement in cardiac functional parameters. In one of the two patients, chronic calcium repletion with high dialysate calcium was associated with significant improvement in cardiac symptoms and a decrease in left ventricular dilatation. These observations suggest that partial parathyroidectomy and associated hypocalcemia place patients on CAPD at increased risk of cardiac dysfunction.     

Vasoactive hormones in uremic patients on continuous ambulatory peritoneal dialysis.

Plasma levels of atrial natriuretic peptide (ANP), renin activity (PRA), and endothelin (ET) are often elevated in uremic patients on hemodialysis treatment. The profile of these vasoactive hormones and their relationships with hemodynamic indices in patients on continuous ambulatory peritoneal dialysis (CAPD), however, are not clear. We therefore measured plasma concentrations of ANP, PRA, ET, together with parathyroid hormone (PTH) in 17 patients (mean age 38.5 years) on maintenance CAPD over a period of 12 weeks. Baseline ANP, PRA, and ET levels were significantly higher than those of healthy subjects, and no significant changes in these indices were observed over the 12 week period. There was a significant positive correlation between levels of plasma ANP and PRA [rank correlation coefficient, R(s) = 0.496, p less than 0.05] as has been reported in cardiac failure. Despite the absence of clinically overt heart failure, a significant proportion (approximately 50%) of our patients demonstrated evidence of myocardial dysfunction on echocardiography. Furthermore, a significant positive correlation was demonstrated between plasma ANP and left atrial size [R(s) = 0.61, p less than 0.01] and an inverse correlation existed between plasma ANP and the left ventricular ejection fraction [R(s) = 0.51, p less than 0.05]. Twelve patients (71%) had biochemical evidence of hyperparathyroidism with raised levels of serum PTH. Our study demonstrates increased levels of plasma ANP, PRA, and ET in uremic patients on long-term CAPD. A positive correlation exists between plasma ANP and PRA suggesting their myocardial function may be compromised and this was confirmed on echocardiography. The possibility that high circulating PTH concentrations contribute to impaired cardiac function in such patients, deserves further study.     

Tuberculous lymphadenitis in patients undergoing continuous ambulatory peritoneal dialysis

The aim of this study was to review the clinical features of tuberculous (TB) lymphadenitis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Nine cases of TB lymphadenitis were diagnosed among 910 patients over a period of 10 years. There were five men and four women with a mean age of 51 ± 15.5 years. The TB lymphadenitis involved the cervical lymph nodes in six patients, supraclavicular lymph nodes in two patients and mediastinal lymph nodes in one patient. Six patients presented with clinically enlarged lymph nodes of whom four also had fever. Three other patients were incidentally found to have enlarged lymph nodes on routine chest X-ray or ultrasound examination of the neck. Diagnosis of TB lymphadenitis was made by demonstrating caseating granulomata with or without positive acid-fast bacilli on excisional lymph node biopsy. All patients were cured with standard anti-tuberculosis drugs for 12 months. No recurrence of the TB lymphadenitis was observed after a mean follow-up of 59 ± 30 months. We conclude that TB lymphadenitis is not uncommon among patients on CAPD. A high index of suspicion is needed for early diagnosis of this condition. Prompt initiation of anti-tuberculosis treatment is associated with good prognosis.     

Ofloxacin pharmacokinetics in patients on continuous ambulatory peritoneal dialysis

Pharmacokinetics of ofloxacin (OFX) was studied in patients on continuous ambulatory peritoneal dialysis (CAPD) carrying out three exchanges per day. In 11 patients given 300 mg of OFX orally, serum OFX concentration peaked at 2.44 mg/l 3.7 hours after administration and the mean elimination half-life of OFX was 25 hours. OFX concentrations in peritoneal fluid underwent cyclical changes with each change of solutions, reaching beyond 0.5 mg/l after 2 hours of equilibration. There was a highly significant correlation between corresponding serum and peritoneal fluid concentrations of OFX after an 8 h equilibration (r = 0.85, p less than 0.001). In 5 patients given a 400 mg loading dose followed by 200 mg of OFX per day for 7 days, trough serum OFX concentrations ranged from 1.35 to 7.00 mg/l and no adverse effects were noticed. CAPD per exchange removed less than 2% of the total dose of OFX given.     

Albumin homeostasis in patients undergoing continuous ambulatory peritoneal dialysis

Albumin and protein removal rates were studied in 18 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). In nine patients simultaneous studies of albumin distribution and turnover were performed. Total albumin loss was 4.23 +/- 1.42 g/1.73 m2/24 hr; total protein removed was 8.79 +/- 4.21 g/1.73 m2/24 hr. Although these values were well within the range for severe nephrosis, serum albumin concentration remained nearly normal, 3.7 +/- 0.5 g/dl. Plasma albumin mass, 120.0 +/- 25.2 g/1.73 m2, and total albumin mass, 249 +/- 29.1 g/1.73 m2, did not differ from those of the control group. Compared with the control group, patients had reduced albumin catabolism, 9.76 +/- 1.74 g/1.73 m2/24 hr versus 13.8 +/- 0.77 g/1.73 m2/24 hr (P less than 0.001). Within the patient group albumin synthesis increased with increased albumin loss. Serum albumin concentration correlated negatively with albumin losses (P less than 0.001). The CAPD patients maintained albumin homeostasis through decreased albumin catabolism and increased synthesis. All major albumin pools were maintained despite massive albumin loss.     

Protein losses in patients receiving continuous ambulatory peritoneal dialysis

Total protein and 12 specific proteins were measured in dialysates from 8 patients on continuous ambulatory peritoneal dialysis during training. Mean daily loss of total protein was 10.5 g and this included 5.2 g albumin, 805 mg of the immunoglobulins G, A and M, 323 mg transferrin and 530 mg of the remaining 7 proteins measured. The plasma to dialysate ratio of protein concentrations correlated with the natural logarithm of molecular weight, suggesting that proteins in dialysate are an ultrafiltrate of plasma. A greater loss of proteins overnight was due to longer dwell time as the mean rate of loss was similar for all exchanges. Losses were similar with 1.36% and 3.86% dextrose fluids, suggesting that the initial effects of hypertonicity are diminished or reversed by dilution and absorption of dextrose. Daily outflow volumes for 4 patients correlated inversely with the quantities of several proteins removed, probably due to effects of osmolality. It is concluded that protein losses are related to plasma concentration, molecular weight and osmolality of the dialysis solution and to the physiology of the patient.     

Procainamide pharmacokinetics in patients on continuous ambulatory peritoneal dialysis

The pharmacokinetics of procainamide in patients on continuous ambulatory peritoneal dialysis have been studied. A mean peak plasma concentration of 3.2 +/- 0.6 microgram/ml was achieved about 2 h after a single 500-mg oral procainamide hydrochloride dose. The procainamide elimination half-life ranged from 6.1 to 15.3 h. Apparent oral clearance, 183.7 +/- 63.2 ml/min, was less than half that observed in healthy adults suggesting markedly reduced dosage requirements. Continuous ambulatory dialysis patients exhibit similar procainamide pharmacokinetic parameters as do end stage renal disease patients, most notably a prolonged elimination half-life and reduced oral clearance.