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.     

Peritoneal clearance of leptin in continuous ambulatory peritoneal dialysis.

Leptin is a 16-kd protein that increases energy expenditure and limits food intake. Serum leptin (S-leptin) is elevated in dialysis patients, and little data have been reported on leptin clearance (Cl) during dialysis. We analyzed the peritoneal dialysis (PD) Cl of leptin in 15 continuous ambulatory peritoneal dialysis (CAPD) patients and compared the results to beta(2)-microglobulin (beta(2)-m), urea, and creatinine PD Cl. S-leptin was significantly elevated (Kruskal-Wallis, P < 0.005) in CAPD women (58.4 +/- 42.4 [SE] microg/L, n = 5) as compared with CAPD men (13.9 +/- 7.1, n = 10) and with healthy women (11.0 +/- 1.4, n = 13) and men (5.1 +/- 0. 9, n = 14). Correlations were found between percent of fat mass and S-leptin (P < 0.05); between S-leptin and the 24-hour PD leptin (P < 0.05); and between dialysate-to-plasma (D/P) beta(2)-m and D/P leptin (P < 0.01). PD leptin Cl (1.80 +/- 0.43 mL/min/1.73 m(2)) was higher than beta(2)-m Cl (1.22 +/- 0.31) (P < 0.01), but reduced as compared with urea Cl (8.84 +/- 1.20) (P < 0.005) and creatinine Cl (7.71 +/- 0.99) (P < 0.005). These results indicate that leptin is eliminated through the peritoneum membrane. However, peritoneal leptin clearance, as beta(2)-m, appears to be clearly restricted as compared with peritoneal transport of smaller molecules. Hence, leptin could use the same diffusion transport pathway as beta(2)-m. In addition, leptin, which has a higher molecular weight than beta(2)-m, was significantly more eliminated into the peritoneal dialysate. More studies are necessary to clarify whether this is an active leptin elimination process by peritoneal secretion or by a different restriction coefficient of diffusion through the peritoneum membrane.     

Peritoneal morphology in children treated by continuous ambulatory peritoneal dialysis

Fifty peritoneal biopsies (PB) from 35 patients with end-stage renal disease, treated by continuous ambulatory peritoneal dialysis (CAPD) and aged 2 months to 18 years, were examined by light microscopy (n=50) and/or scanning electron microscopy. PB were performed during surgical procedures immediately before the start of, during, or after the cessation of CAPD treatment. PB from 15 children without renal disease undergoing laparatomy were examined similarly. Before the start of CAPD, a scarcity and shortening of the mesothelial microvilli was observed by scanning electron microscopy. During and after CAPD, variable alterations of mesothelium, interstitium and capillaries were found. The mesothelial layer was absent in all 5 PB obtained during episodes of active peritonitis. In patients treated by CAPD for longer than 6 months, mesothelial denudation was observed more frequently (6/11) than in children treated for shorter periods (1/7) (P<0.08). Fibrosis of the peritoneal membrane was present in about 50% of patients during or after the cessation of CAPD without impairment of peritoneal function. No correlation was found between the presence of fibrosis and the frequency of peritonitis or the duration of CAPD treatment.     

Peritoneal mucormycosis in a patient receiving continuous ambulatory peritoneal dialysis

A 48-year-old man receiving maintenance hemodialysis for 3 years and continuous ambulatory peritoneal dialysis for 1 year developed a clinical picture compatible with peritonitis. Three successive fluid cultures were negative, and only after filtration of a large volume of peritoneal fluid a fungus identified as a Rhizopus sp was isolated in cultures of the filtering devices. The same fungus was also isolated from the peritoneal catheter cuff. Intravenous amphotericin B was administered and both the abdominal and general conditions of the patient improved transiently. Twenty days after initiation of antifungal treatment, a clinical suspicion of intestinal perforation arose and an exploratory laparotomy was scheduled, but the patient died during the anesthetic induction. The patient never received deferoxamine; any conditions predisposing to mucormycosis, such as diabetes or immunosuppression, were also absent.     

Peritoneal complications during continuous ambulatory peritoneal dialysis: surgical aspects

The principal complication of continuous ambulatory peritoneal dialysis (CAPD) is peritonitis in most cases benign and treated effectively by local, specific antibiotic therapy. In some cases, however, the infection fails to respond to medical treatment and surgical exploration occasionally reveals serious lesions such as sclerosing peritonitis or an intestinal perforation. Prognosis is dependent not only on the extent and severity of the lesion but also on the rapidity of operative intervention. The development of an appendicitis, often masked by early antibiotic therapy, represents a particular course of peritoneal infection during CAPD.     

Peritoneal elimination of homocysteine moieties in continuous ambulatory peritoneal dialysis patients

BACKGROUND: The amount of total homocysteine eliminated by peritoneal dialysis and its relationship to peritoneal transport characteristics in continuous ambulatory peritoneal dialysis (CAPD) patients are unknown. METHODS: The influence of total homocysteine, folate, and vitamin B12 plasma concentrations, serum albumin levels, age, sex, dialysate to plasma ratio (D/P) creatinine, D/D0 glucose, D/P albumin, dialysate effluent volume, and effluent albumin on the daily peritoneal excretion of total homocysteine was investigated in 39 CAPD patients. The relationship of D/P creatinine to D/P total homocysteine, D/P free homocysteine, and D/P protein-bound homocysteine was analyzed additionally in a subgroup of 25 patients. RESULTS: We observed a significant influence of plasma total homocysteine concentrations (P = 0.0001) of the daily dialysate effluent volume (P = 0.0221) and of the D/P creatinine (P = 0.0132) on peritoneal elimination of total homocysteine. The daily peritoneal excretion of total homocysteine was 38.94 +/- 20.82 mumol (5.27 +/- 2.81 mg). There was a positive linear association of the daily total homocysteine elimination with plasma total homocysteine concentrations (P = 0.0001). A significant linear correlation was observed between D/P creatinine and D/P total homocysteine (P = 0.0001), D/P free homocysteine (P = 0.0001), as well as D/P protein-bound homocysteine (P = 0.0001). CONCLUSIONS: The peritoneal elimination of total homocysteine primarily depends on the plasma total homocysteine concentration. Elevated total homocysteine plasma levels cannot be reduced efficiently by peritoneal dialysis.     

Peritoneal kinetics in children undergoing continuous ambulatory/cycling peritoneal dialysis

We present a report on peritoneal kinetics in children undergoing continuous ambulatory/cycling peritoneal dialysis (CAPD/CCPD). The effect of long-term treatment with CAPD/CCPD, peritonitis episodes, and dialysate inflow volume on peritoneal kinetics in children was evaluated. Peritoneal kinetic studies (PKSs) were performed in 47 pediatric patients at different times following initiation of CAPD/CCPD. In 18 of these patients, PKSs were repeated up to four times with an unchanged dialysate inflow volume after up to 55 months of CAPD/CCPD treatment. The PKS consisted of a 120-minute dwell with a 1.5% dextrose dialysate solution. Peritoneal clearance, dialysance, and dialysate to plasma (D/P) concentration ratios were calculated after 30, 60, and 120 minutes. The results of the serial PKSs demonstrate stable peritoneal creatinine and urea-N clearance, dialysance or D/P concentration ratios. Furthermore, there was no adverse effect of 32 peritonitis episodes. Finally, inflow volumes correlated directly with clearances of creatinine (P less than .01), urea-N (P less than .001), and potassium (P less than .001), and there was an inverse relationship to the D/P concentration ratios of creatinine (P less than .01), urea-N (P less than .01), potassium (P less than .01), and uric acid (P less than .01). Thus, CAPD/CCPD is a useful and effective long-term treatment modality for pediatric patients. Maximal dialysate inflow volumes should be provided to enhance peritoneal kinetics.     

Peritoneal eosinophilia associated with Paecilomyces variotii infection in continuous ambulatory peritoneal dialysis

A 65-year-old woman maintained on continuous ambulatory peritoneal dialysis (CAPD) presented with a 5-month history of intermittent cloudy bags and sterile peritoneal and peripheral blood eosinophilia, which failed to clear despite conventional antibiotics. Impaired catheter inflow and delayed effluent drainage gradually occurred and intracatheter streptokinase, administered to rectify catheter dysfunction, dislodged a catheter cast composed of fungal hyphae of Paecilomyces variotii. Fungal peritonitis and Paecilomyces fungemia ensued, which were treated with amphotericin B and catheter removal. Peripheral eosinophilia rapidly resolved. Paecilomyces is a saprophytic fungus found in soil and water that is capable of infecting prosthetic devices. Eosinophils may have accumulated in this case in response to particulate fungal cell antigens being washed into the peritoneal cavity during dialysis. Chronic fungal catheter infection should be excluded in cases of late onset, persistant peritoneal eosinophilia on CAPD.     

Peritoneal sodium mass removal in continuous ambulatory peritoneal dialysis and automated peritoneal dialysis: influence on blood pressure control.

BACKGROUND/AIM: Sodium and water retention is common in peritoneal dialysis patients and contributes to cardiovascular disease. As peritoneal sodium removal depends partly on dwell time, and automated peritoneal dialysis (APD) often uses short dwell time exchanges, the aim of this study was to compare the 24-hour peritoneal sodium removal in APD and standard continuous ambulatory peritoneal dialysis (CAPD) patients and to analyze its possible influence on blood pressure control. METHODS: A total of 53 sodium balance studies (30 in APD and 23 in CAPD) were performed in 36 stable peritoneal dialysis patients. The 24-hour net removal of sodium was calculated as follows: M = ViCi - VdCd, where Vd is the 24-hour drained volume, Cd is the solute sodium concentration in Vd, Vi is the amount of solution used during a 24-hour period, and Ci is the sodium concentration in Vi. Peritoneal sodium removal was compared between APD and CAPD patients. Residual renal function, serum sodium concentration, daily urinary sodium losses, weekly peritoneal Kt/V and creatinine clearance, 4-hour dialysate/plasma creatinine ratio, proportion of hypertonic solutions, net ultrafiltration, systolic and diastolic blood pressures, and need for antihypertensive therapy were also compared between the groups. RESULTS: Peritoneal sodium removal was higher (p < 0.001) in CAPD than in APD patients. There were no significant differences in residual renal function, serum sodium concentration, urinary sodium losses, peritoneal urea or creatinine clearances, 4-hour dialysate/plasma creatinine ratio, or proportion of hypertonic solutions between groups. The net ultrafiltration was higher in CAPD patients and correlated strongly (r = 0.82; p < 0.001) with peritoneal sodium removal. In APD patients, peritoneal sodium removal increased significantly only in those patients with a second daytime exchange. The systolic blood pressure was higher (p < 0.05) in APD patients, and the proportion of patients with antihypertensive therapy was also higher in APD patients, although no significant relationship between blood pressure values and amount of peritoneal sodium removal was found. CONCLUSIONS: The 24-hour sodium removal is higher in CAPD than in APD patients, and there is a trend towards better hypertension control in CAPD patients. As hypertension control and volume status are important indices of peritoneal dialysis adequacy, our results have to be considered in the choice of the peritoneal dialysis modality.     

Peritoneal eosinophilia in patients on continuous ambulatory peritoneal dialysis: a prospective study

A prospective study on peritoneal eosinophilia was conducted in 23 continuous ambulatory peritoneal dialysis (CAPD) patients for a mean period of 7.9 months. Peritoneal eosinophilia as defined by peritoneal eosinophil count exceeding 100/mm3 was found in 60.8% of patients. Most developed peritoneal eosinophilia within 3 months of the initiation of dialysis, although the phenomenon could occur as early as one day or as late as 6 months after dialysis. Fifty-seven percent of those with peritoneal eosinophilia also had peripheral blood eosinophilia. Although most peritoneal eosinophilic episodes subsided in a month, in one patient the process grumbled on for 150 days. The number of peritonitis episodes was not significantly different between patients with peritoneal eosinophilia and those without. The only distinction between the two groups of patients was that those who developed peritoneal eosinophilia had a significantly (P = .002) higher serum IgE concentration initially as well as throughout the period of observation.     

Peritoneal permeability to proteins in diabetic and non-diabetic continuous ambulatory peritoneal dialysis patients

Peritoneal permeability to proteins was measured in diabetic and non-diabetic continuous ambulatory peritoneal dialysis patients during peritonitis and control periods. Clearances of albumin, transferrin, IgG, C3 and alpha 2-macroglobulin appeared to decrease as molecular weight increased. This relationship could be described by a power curve fit. The decrease was more than could be explained by differences in free diffusion only, indicating a size-selective barrier in the peritoneum. For all measured proteins clearances were higher in the diabetic patients. This may reflect a generally increased permeability due to their microangiopathy. The largest increase in protein loss and protein clearances was found during peritonitis. Our results do not suggest increased local production of any of the investigated proteins during the inflammation. Therefore, an increase in either peritoneal permeability or effective surface area or both is the most likely explanation. It is concluded in this study that peritoneal protein clearances are dependent on their molecular weight and that they are proportionally increased in patients with diabetes and during peritonitis.     

Biocompatibility parameters in in-vitro simulated automated versus continuous ambulatory peritoneal dialysis

BACKGROUND: In peritoneal dialysis, the usage of automated peritoneal dialysis (APD) has been steadily increased. As APD means larger volumes of solution and more frequent contact times with fresh dialysate, an additive negative impact on biocompatibility data, exceeding the known effect of conventional PD fluids, seems possible. For an in-vitro comparison of APD and CAPD, a new cell culture system has recently been established. METHODS: A double chamber cell culture system with human mesothelial cells on top of a permeable membrane and growth medium beyond was used for mimicking CAPD and APD. Reflecting the in vivo equilibration pattern, we compared an eight-hour CAPD with a CCPD setting, using a conventional PD solution. Cell viability was assessed with a MTT assay and cell function via constitutive and stimulated IL-6 release. CA125 was measured as a parameter of mesothelial cell integrity, and TGF-1beta was measured as an index of induction of fibrosis. RESULTS: Both the CAPD and the CCPD mode resulted in a significantly lower MTT assay and stimulated IL-6 release compared to growth medium. TGF-1beta and CA125 release did not differ between the PD modes and control. The CAPD and the CCPD mode itself did not differ with regard to MTT assay, IL-6 release, TGF-1beta and CA125 generation. CONCLUSION: From the in-vitro model imitating the acute exposure of mesothelial cells with conventional PD fluid in a CCPD and CAPD mode, there is no evidence that APD, due to the larger volumes of solution and more frequent contact times with fresh dialysate, has an acute, additive negative impact on biocompatibility parameters indicative for peritoneal host defense, mesothelial cell integrity and peritoneal fibrosis.     

Catheter-related complications of continuous ambulatory peritoneal dialysis.

OBJECTIVE--To assess the effectiveness of continuous ambulatory peritoneal dialysis (CAPD) with particular reference to morbidity. DESIGN--Open study. SETTING--Two city general hospitals. SUBJECTS--104 Adults and 11 children with end stage renal failure. MAIN OUTCOME MEASURE--Morbidity. RESULTS--There were 29 complications (25%), the most common being obstruction of the tube (n = 8, 7%), and migration of the tube (n = 7, 6%). Others were peritonitis (n = 5), haemorrhage (n = 4), infection at the exit site (n = 3), and leakage of fluid (n = 2). All were readily treatable. CONCLUSIONS--Fixing the catheter in two places may prevent its migration. The complication rate of CAPD is acceptable, and in children with end stage renal failure it is a suitable alternative to haemodialysis while they are waiting for renal transplantation.     

Factors influencing peritoneal catheter survival in continuous ambulatory peritoneal dialysis.

The success of continuous ambulatory peritoneal dialysis (CAPD) is to a great extent determined by the survival of the peritoneal catheter. The aim of this study was to identify technical factors which influence CAPD catheter survival. A total of 453 CAPD catheters inserted into 310 patients over an 8-year period were analysed. Access to the peritoneum was gained either by an open surgical technique (n = 290) or by a closed technique using a trocar and introducer (n = 163). Data relating to a number of potentially significant risk/benefit factors were analysed using multiple regression analysis (proportional hazards method of Cox). Three factors were found to be independently associated with improved catheter survival. They were: using an open surgical insertion technique, performing a partial omentectomy at the time of catheter insertion and the procedure being performed by a consultant.