Claudia Castelnovo

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.

High Prevalence of Silent Gallstone Disease in Dialysis Patients

Gallstone disease was detected in 28% of 119 patients on regular dialysis treatment. The disease was silent in 82% of the patients. Stones were radiolucent in 88% of the cases, radioopaque in 8% and mixed in 4%. Among 49 variables considered, increasing age was the only variable that correlated significantly with increasing prevalence of gallstone disease. Since no relationships were found between gallstones and age or modes of dialysis, it is conceivable that some mechanism(s) linked with the preexisting chronic nephropathy might have been involved in the development of cholelithiasis. End-stage renal disease could be another so far unrecognized risk factor for cholelithiasis.

Long-Term Incidence of Peritonitis in CAPD Patients Treated by the Y Set Technique: Experience in a Single Center

Our experience of peritonitis in 156 patients over an 8-year period represents 186 episodes of peritonitis and 4,964 patient-months of CAPD. The incidence of peritonitis was significantly greater (1 episode every 8.6 patient-months) when the Oreopoulos technique was used and dropped to 1 episode every 43.3 patient-months when the Y set system was used. Of the 109 patients using the Y set system, 88 (80.7%) never had episodes of peritonitis, whereas only 7 (16.7%) of the 42 patients using the Oreopoulos technique were free of peritonitis. For 23 patients shifted from the Oreopoulos to the Y set technique, the incidence of peritonitis dropped from 1/9.8 to 1/35.2 episodes/patient-months.

Plasma and dialysate immunoglobulin G in continuous ambulatory peritoneal dialysis patients : a multicenter study

Peritoneal dialysate immunoglobulin (Ig)G concentrations were measured in 120 continuous ambulatory peritoneal dialysis (CAPD) patients evaluated at four dialysis centers in different countries to assess the normal range for dialysate IgG and to investigate the relationships of this protein levels with peritoneal episodes, For 65 of these patients, plasma IgG levels were determined, and IgG clearances were calculated. The mean dialysate concentration of IgG was 6.9 +/- 4.2 mg/dl, and there was no difference between men and women or between patients who had or had not previously undergone hemodialysis. Dialysate IgG concentrations were significantly related to residual renal creatinine clearance and negatively correlated with dialysate volume, plasma albumin and total protein. There were no significant correlations between IgG levels in the dialysate and age, protein losses in the dialysate, time on CAPD or time from the last peritonitis episode. Plasma and dialysate IgG were unrelated to the incidence of peritonitis, statistical analysis being performed with different methods. These results suggest that IgG levels in the dialysate or plasma are not a major factor in the prevention of CAPD peritonitis.

Nine patients treated for more than 10 years with continuous ambulatory peritoneal dialysis

We have retrospectively examined the clinical outcomes of the 9 patients who survived for more than 10 years in our continuous ambulatory peritoneal dialysis (CAPD) program. Six were men and 3 women aged 50.8 +/- (SD) 11.5 years. Three had been previously treated by hemodialysis. None of them had diabetes or neoplasms, 1 had liver cirrhosis, 3 had ischemic cardiopathy, 1 had peripheral artery disease, and all were hypertensive. The hospitalization rate ranged from 0 to 4.5 days/patient/year, the peritonitis rate was one episode every 57 months. Six patients had no peritonitis during the first 10 years of treatment. Exit-site episodes were one every 46.7 patient months. Six peritoneal catheters were removed from 4 patients. KT/V and peritoneal permeability, assessed by the peritoneal equilibration test, were within the normal range in the majority of the patients. Five patients died between the 121st and the 149th month, and 4 are still alive. Three of them are working. These results show that CAPD can be effective, peritoneal catheters can survive, and some patients can be free from peritonitis episodes for more than 10 years. After the 10-year on CAPD, the survival is poor, and the morbidity is high.

Recombinant Hepatitis B Vaccine Adjuvanted With AS04 in Dialysis Patients: A Prospective Cohort Study

Background/Aims: Patients undergoing maintenance dialysis have an unsatisfactory response to vaccination, including to hepatitis B vaccine. A recombinant HB vaccine containing a new adjuvant system AS04 (HBV-AS04) has been recently developed; a few data exist on the immunogenicity and safety of HBV-AS04 among patients undergoing regular dialysis. All hepatitis B virus-seronegative patients with undetectable antibody against HBsAg undergoing maintenance dialysis at two units were prospectively included. Methods: Patients received four 20-mcg doses of HBV-AS04 by intramuscular route (deltoid muscle) at months 0,1,2, and 3. Anti-HB surface antibody concentrations were measured at intervals of 1, 2, 3, 4, and 12 months. Univariate and multivariate analyses determined which parameters predicted immunologic response to HBV-AS04 vaccine. Results: 102 patients were enrolled and 91 completed the study. At completion of the vaccination schedule, using per-protocol analysis, 76 of 91 (84%) had antibody titers ≥10 mIU/mL with anti-HBs geometric antibody concentrations (GMCs) of 385.25 mIU/mL. The sero-protection rate at month 12 was 84% (48/57) with lower GMCs (62.74 mIU/mL, P<0.0001). Multivariate analysis revealed a detrimental role of age on the immune response to HB-AS04 vaccine (F Ratio, 4.04; P<0.04). Tolerance to HBV-AS04 was good and only minor side-effects were observed. Conclusions: HBV-AS04 vaccine was highly immunogenic in our cohort of patients on maintenance dialysis even if a significant number of non-responders is still present. Prospective studies with HBV-AS04 on larger study groups and with longer follow-ups are under way.

Calcimimetics in peritoneal dialysis patients.

Though the prevalence of secondary hyperparathyroidism (SHP) and the related mineral metabolism (MM) changes have been reported at almost the same rate in peritoneal dialysis (PD) as in hemodialysis (HD) patients, PD patients have a higher prevalence of adynamic bone disease (ABD), suggesting that their bone is less sensitive for a given level of PTH. Furthermore, the phosphorus control seems to be better and vitamin D deficiency is more common in PD patients than in HD patients. So, the therapeutic approach to SHP and MM changes in PD patients might be different from the one applied to HD patients. Vitamin D metabolites and phosphate binders, though effective in controlling SHP of CKD patients, are not equally effective in controlling at the same extent calcium and/or phosphorus levels. Recently, a new drug (Cinacalcet) has been introduced in the clinical practice which significantly increased the chance of obtaining a simultaneous control of both PTH and MM parameters. However, only scanty data are present in the literature regarding the use of Cinacalcet in PD patients. The few studies produced in PD retraced the results obtained in hemodialysis patients, confirming that both in the short- and long-term Cinacalcet induced a more pronounced reduction of PTH in a larger percentage of patients as compared with standard therapy (ST), and this effect was associated with a decrease in both calcium and phosphorus concentrations, though the extent of the percentage decrease of phosphorus was lower than in HD patients. The safety/tolerability profile was again the same as in HD patients, with gastrointestinal symptoms representing the more frequently reported side effects. In our experience, given that a severe form of SHP is less frequent, the control of phosphate is usually better and vitamin D deficiency is more frequent in PD than in HD patients, making the former patients more prone to hypo- rather than hypercalcemia, the need for the use of the most recent and potent drugs for the control of SHP, including Cinacalcet, is usually lower in PD than in HD patients.

Intermediary Metabolism and Glycemic Control in Insulin-Dependent Diabetic Uremic Patients Treated by Continuous Peritoneal Dialysis

The effect on metabolic control and on intermediate metabolism of continuous ambulatory peritoneal dialysis (CAPD) was evaluated in 6 insulin-dependent diabetic uremic patients treated by CAPD, in 6 nondiabetic uremic patients in CAPD and in 6 normal subjects. During the study, 4 dialysis exchanges with 1.36 g/dl dextrose concentration were performed daily; regular insulin was added to the bags in diabetic patients. Our data show a well-controlled mean blood glucose in CAPD diabetic patients by intraperitoneal insulin administration as well as higher insulinemic levels in comparison with those of normal subjects. Plasma lactate and serum glycerol levels were higher and butyrate levels were lower reflecting a continuous ketogenesis inhibition.

Continuous ambulatory peritoneal dialysis in patients after intra-abdominal prosthetic vascular graft surgery

The purpose of this study was to assess the feasibility of continuous ambulatory peritoneal dialysis (CAPD) after intra-abdominal prosthetic vascular graft surgery. We report 8 consecutive patients with end-stage renal disease, who previously underwent intra-abdominal prosthetic aortic graft replacement, treated by CAPD between November 1983 and November 1994. All patients received a peritoneal dialysis catheter without technical problems and were dialyzed for a total of 208 months. Six episodes of peritonitis occurred in 4 patients without clinical evidence of any abdominal aortic graft infection. Three patients developed intermittent claudication and 2 died of myocardial infarct. A similar peritonitis and cardiovascular complication rate was observed in a control group of age- and sex-matched CAPD patients with no aortic prosthesis. We conclude that CAPD is feasible in patients with abdominal aortic prosthesis.

Active Chloride Concentration in CAPD Systems Containing In-Line Disinfectant Electrolytic Chloroxidizer Solution

Dr. Amedeo De Vecchi, Divisione di Nefrologia e Dialisi, Padiglione Croff, Ospedale Maggiore, Via Commenda 15, I-20122 Milano (Italy) Dear Sir, Amuchina is a disinfectant electrolytic chloroxidizer solution [1] largely used as in line disinfectant in some Y-systems to prevent exogenous peritonitis [2]. This disinfectant can be inactivated by light, by the organic compounds contained in peritoneal fluid and by glucose solutions [1], but no data are available on the in vivo inactivation of Amuchina in the Y-systems. Forty-six inand outpatients were invited to record the type of dialysis solution used for the last CAPD exchange and were requested to come to the hospital at different times after the last CAPD exchange. They used three different Y-set systems: the long-branched Baxter Y-set [3,4], the short-branched Baxter Y-set [5] and the Bieffe L3 disposable double-bag system [6]. Before the bag exchange, expert nurses drained the whole amount of Amuchina from the Y-set branches (long and short Y-set), from the cap of the long Y-set spike or from the cap of the patient connection (L3 system) into a sterile dry glass. The glass was immediately closed to prevent evaporation and taken to the laboratory. The content of the set was weighed with a precision scale. Active chloride was measured by iodometric titration. Five milliliters of KJ 10% solution and 5 ml of 1 TV acetic acid were added to the sample; the mixture was titrated by 0.1 JVsodium thiosulfate, using starch indicator. The amount of active chloride was calculated by the formula: (A × C × 35.45)/B, where A = ml of sodium thiosulfate, B = ml of initial sample, C = normality of sodium thiosulfate. In a first step of the study we studied the concentration of active chloride in different