Peritoneal Dialysis International: Journal of the International Society for Peritoneal Dialysis

Single-dwell studies in rats and humans have shown that supplementing citrate for lactate in peritoneal dialysis (PD) fluids improves ultrafiltration (UF).

The long-term effects of citrate-substituted PD fluids on PD catheter patency, UF, and peritoneal morphology were evaluated in a rat model over 5 weeks of daily PD fluid exposure. A standard 2.5% glucose 40 mmol/L lactate PD fluid and a corresponding 10/30 mmol/L citrate/lactate PD fluid were compared. In a control group, rats with catheters received no PD fluid.

The average patency time (% of 36 days) of silicone rubber PD catheters was significantly longer in the citrate PD group (98.8% ± 1.2%) and the control group (100% ± 0%) compared to the lactate PD group (54.7% ± 9.5%). In a separate experiment, heparin-coated polyurethane catheters were used to study peritoneal morphology and fluid transport. The citrate group had a higher net UF than the lactate group at the beginning and at the end of the 5 weeks. During the experiment, both fluid-treated groups suffered from UF loss; the control group showed the highest net UF at the end of the 5 weeks. Peritoneal vascular density and submesothelial thickness, indicators of angiogenesis and fibrosis, were not significantly different among the groups. Fibrosis was significantly negatively correlated to osmotic UF.

A positive acute effect of citrate on UF was confirmed and conserved over time. Citrate PD strongly improved PD catheter patency time compared with lactate. Both citrate PD and lactate PD induced negative long-term effects on UF compared with control animals.

Lipid abnormalities, particularly high serum concentration of lipoprotein(a) [Lp(a)], are one of the major risk factors for cardiovascular disease (CVD) in peritoneal dialysis (PD) patients. The present study was designed to investigate the effects of soy consumption on serum lipids and apoproteins, especially Lp(a), in PD patients.

This study was a randomized clinical trial in which 40 PD patients (20 males, 20 females) were randomly assigned to either the soy or the control group. Patients in the soy group received 28 g/day textured soy flour (containing 14 g of soy protein) for 8 weeks, whereas patients in the control group received their usual diet, without any soy. At baseline and the end of week 8 of the study, 5 mL of blood was collected from each patient after a 12- to 14-hour fast and serum triglyceride, total cholesterol, low density lipoprotein-cholesterol (LDL-C), high density lipoprote-incholesterol (HDL-C), apoprotein B100 (apo B100), apoprotein AI (apo AI), and Lp(a) were measured.

In the present study, serum Lp(a) concentrations were above the normal range in 86% of the PD patients. Mean serum Lp(a) concentration was reduced significantly, by 41%, in the soy group at the end of week 8 compared to baseline (p < 0.01); the reduction was also significant compared to the control group (p < 0.05). During the study, mean serum Lp(a) concentration did not change significantly in the control group. There were no significant differences between the two groups in mean changes in serum triglyceride, total cholesterol, HDL-C, LDL-C, apo B100, or apoAI.

The results of our study indicate that soy consumption reduces serum Lp(a) concentration, which is a risk factor for cardiovascular disease in peritoneal dialysis patients.

To determine whether oral administration of the antifungal fluconazole during the entire period of treatment of bacterial peritonitis (BP), exit-site infection (ESI), or tunnel infection (TI) prevents later appearance of fungal peritonitis (called secondary) in patients with chronic kidney disease stage 5 in a peritoneal dialysis (PD) program.

All patients treated in the PD program in RTS Ltda Sucursal Caldas, during the period 1 June 2004 to 30 October 2007 were screened. Patients that had infectious bacterial complications (BP, ESI, TI) were included in a prospective randomized trial to receive or not receive oral fluconazole (200 mg every 48 hours) throughout the time period required by the administration of therapeutic antibiotics via any route. It was evaluated whether the fungal peritonitis complication appeared within 30 – 150 days following the end of antibacterial treatment. Based on local results, the sample size necessary to obtain statistically significant results was determined to be 434 episodes of peritonitis.

The 434 episodes of peritonitis presented between the previously specified dates and during this same period there were 174 ESI or TI, of which only 52 received oral antibiotic treatment. Information in relation to consumption of antibiotics for purposes other than BP, ESI, and TI was not reliable and thus this variable was excluded. Among the episodes of peritonitis, 402 (92.6%) were of bacterial origin and 32 (7.3%) were mycotic, mainly Candida species [30 (93.75%)]. Of the fungal peritonitis, 14 (43.73%) were primary (without prior use of antibiotics) and 18 (56.25%) were secondary. In the group of patients that received prophylaxis with fluconazole (210 for BP and 26 for ESI or TI), only 3 occurrences of fungal peritonitis were observed within 30 – 150 days of its administration, which is opposite to the group without prophylaxis (210 for BP and 26 for ESI or TI), in which 15 occurrences of fungal peritonitis were detected. Statistical analysis of the group of patients with BP found comparisons of the proportions of those receiving fluconazole (0.92%) or not (6.45%) presented a highly significant difference in favor of prophylaxis (p = 0.0051, Z = 2.8021). Given that only 1 patient in each group with ESI or TI, with or without prophylaxis, presented the complication fungal peritonitis, it was concluded that this result was not statistically significant. During laparoscopic surgery attempting reintroduction of the peritoneal catheter, it was found that 11 patients had severe adhesions or peritoneal fibrosis leading to obliteration of the peritoneal cavity. In 19 patients, reintroduction of the catheter was possible and the patients returned to PD without consequence.

In patients with bacterial peritonitis, administration of prophylactic oral fluconazole throughout the time they received antibiotics significantly prevented the appearance of secondary fungal peritonitis.

The present study was performed to explore the range of effects of amino acid-based peritoneal dialysis (PD) solutions on glucoregulatory hormones in comparison with an osmotically equivalent glucose-based solution.

13 adult nondiabetic patients on PD underwent 2 peritoneal dwells of 2 hours’ duration with either 1.5% dextrose solution or 1.1% amino acid solution. Serial sampling for glucoregulatory hormones was done throughout the duration of the dwell.

Instillation of the 1.5% dextrose solution resulted in a modest change in plasma glucose, paralleled by a small increase in plasma insulin levels and plasma insulin-like growth factor (IGF-1). Plasma glucagon was not changed and plasma growth hormone level declined. Instillation of the 1.1% amino acid solution resulted in an increase in plasma glucose, plasma insulin, plasma glucagon, and plasma IGF-1. Plasma growth hormone level declined. Both solutions led to an increase in plasma norepinephrine but no changes were observed in epinephrine or dopamine.

Our observations suggest that the mere replacement of glucose by amino acids in PD solutions does not necessarily imply “glucose sparing” from the perspective of induction of a glucoregulatory hormonal response because of the aminogenic stimulation of secretion of multiple hormones.

Inadequate dialysis is still a major cause of technique failure in peritoneal dialysis (PD). Mathematical models provide the possibility of direct and precise assessment of peritoneal transport of urea and creatinine throughout the dwell and allow calculation of optimal schedules, dwell times, and predicted adequacy of a prescribed regimen. Kinetic modeling is particularly important for automated PD. If the effectiveness of uremic toxin removal that takes place during infusion and drainage of dialysis fluid is not taken into account, the predicted adequacy of the whole PD session may be underestimated.

To estimate the efficacy of urea and creatinine removal during the dialysis fluid exchange procedure.

17 patients treated with PD were included in the study. PD effectiveness during dialysate exchange was defined as the quotient k of removed amount of creatinine/BUN during the infusion and drainage of dialysate and during a dwell of the same duration as the dialysate exchange.

The effectiveness of creatinine and urea removal was reduced during the exchange procedure (k_creat = 0.68 ± 0.43 and k_BUN = 0.87 ± 0.44) and differed between these 2 solutes (p = 0.0009). The k coefficients for urea and creatinine were well correlated (R² = 0.83).

The effectiveness of peritoneal transport of creatinine and BUN during the inflow/outflow phase was relatively high compared to that during the same dwell time (68% and 87% respectively). This real effectiveness of the dialysate exchange procedure should be taken into account in the process of planning automated PD sessions, otherwise the predicted overall efficacy of creatinine and urea removal throughout the session may be underestimated. This underestimation is proportional to the number of dwells per day.

Less than 10% of end-stage renal disease (ESRD) patients in Taiwan receive peritoneal dialysis (PD), which reveals the situation of underutilization of PD. We thus aimed to investigate factors associated with treatment with PD in ESRD patients in Taiwan.

Patients that were 18 years of age or older and had been on dialysis for at least 3 months since 2001 were recruited and interviewed with a structured questionnaire.

98 hemodialysis (HD) and 102 PD patients were recruited. In univariate analysis, age, sex, level of education, employment status, marital status, traffic time, family support, patient cognition, and receptivity were correlated with treatment with PD. Multivariate analysis showed that patients that were not married (p = 0.006), that spent more time traveling to the dialysis clinic (p = 0.006), that were not emergent at the start of dialysis (p = 0.003), and that had better family support (p = 0.045), a higher cognition of dialysis (p = 0.034), and stronger receptivity to dialysis (p < 0.001) were more likely to receive PD.

We recommend patients follow the standard process to obtain more exhaustive information, consultation, and early referral. In addition, we suggest healthcare providers remind patients to take into account such nonclinical factors as family support and patient receptivity when they choose their dialysis modality.

Peritoneal dialysis (PD)-related peritonitis is a common and morbid complication of PD. Bacteria are able to create a biofilm on the PD catheter, which can be a source of recurrent infection. Biofilms undergo a phenotypic change resulting in increased antibiotic resistance.

21 clinical isolates of different patients with PD peritonitis secondary to Staphylococcus aureus were collected. They were analyzed for their antibiotic susceptibility in the planktonic form using the standard minimum inhibitory concentration (MIC) and in a biofilm using minimum biofilm eradication concentration (MBEC). Chi-square was used to compare the sensitivity results.

The isolates were susceptible to all the antibiotics tested using MIC. Every antibiotic except gentamicin lost its efficacy when the bacteria were grown in a biofilm (p > 0.05). The change in susceptibility was statistically significant to a level of p < 0.001 for all antibiotics tested.

In PD peritonitis that is long standing, recurrent, or not responsive to therapy, MBEC testing should be considered as a biofilm may be present. Gentamicin should be strongly considered over other agents for empiric gram-negative coverage as it may be providing synergy in the setting of Staphylococcus aureus. Also, the newer anti-staphylococcal drugs should be tested for their performance in a biofilm using the MBEC method.