Advances in peritoneal dialysis. Conference on Peritoneal Dialysis最新文献

Among women with chronic kidney disease, successful pregnancy with a surviving infant is rather rare. Although these pregnancies carry higher risk, with the possibility of adverse maternal and fetal outcomes, they can be managed with close monitoring and intense renal replacement therapy. Given the hemodynamic advantages of peritoneal dialysis over hemodialysis in pregnancy, peritoneal dialysis therapy is thought to be a favorable renal replacement option in pregnant patients with chronic kidney disease.

The underlying pathophysiology that leads to morphologic and functional changes in the peritoneal membrane over time among patients on peritoneal dialysis is not well understood. Many studies have been conducted to try to abrogate those changes and so preserve peritoneal function. Conventional interventions that attempt to accomplish that end include prevention of peritonitis, timely removal of the peritoneal catheter in the face of non-resolving peritonitis, use of biocompatible dialysate, and limitation of total glucose exposure by avoiding hypertonic dextrose solutions. Inhibition of the renin-angiotensin-aldosterone and vascular endothelial growth factor systems, peritoneal resting, combined peritoneal dialysis and hemodialysis, and N-acetylcysteine and gene therapy are more novel and experimental attempts to preserve the peritoneal membrane. We review the novel studies that have aimed to promote the health and function of this dialyzing membrane.

In a comprehensive evaluation of dialysis adequacy, major attention has been recently paid to fluid and Na balance. Removal of Na has been reported to be significantly poorer with automated peritoneal dialysis (APD) than with continuous ambulatory peritoneal dialysis. Only limited data on Na removal with tidal APD have been published. We analyzed peritoneal Na mass balance in 122 separate nightly tidal APD sessions performed by 7 peritonitis-free, clinically stable, patients with negligible residual renal function (< 100 mL urine daily). Correlations with other efficiency measures [ultrafiltration (UF) and small-solute clearances], prescriptive parameters [duration of treatment, initial intraperitoneal fill volume (IPV) and its tidal percentage, and dialysate flux] and peritoneal transport status were tested in univariate and multivariate linear regression models. Removal of Na was 89 +/- 55 mmol per treatment, which correlated with UF (r = 0.29, p = 0.001) and was higher in patients with high-average transport (118 +/- 41 mmol vs. 81 +/- 56 mmol in low-average transporters, p = 0.0004), in whom a significant positive correlation was found with initial IPV and duration of treatment (r = 0.55; 95% confidence interval: 0.21 to 0.77; p = 0.0029; and r = 0.66; 95% confidence interval: 0.38 to 0.83; p = 0.0002 respectively). Removal of Na correlated weakly with UF in tidal APD and showed wide inter-patient variability. It should therefore be measured rather than roughly estimated from UF. Its magnitude exposes the anuric patient on nightly APD with a "dry" day to the risk of Na retention, unless controlled Na intake or dialytic strategies aimed at enhancing Na removal, or both, are implemented.

Recent studies have clearly demonstrated that start ing treatment with peritoneal dialysis (PD) is superior to starting with conventional hemodialysis (HD) because PD preserves residual renal function for a longer period. Similarly, because of the frequency of treatments, home HD (HHD) is also superior to conventional HD. The accumulated evidence suggests that a combination of PD and HHD might be a new and effective method for patients receiving dialysis therapy. We analyzed 10 patients who, over the past 10 years, were started on PD and who were then transferred to HHD. Electronic databases were used to examine changes in their health status. Mean age was 58 +/- 8 years in these 2 female and 8 male patients. Mean duration of PD was 6.9 +/- 2.4 years. The average total duration of dialysis therapy was 9.7 +/- 1.9 years. The main reason for the transition from PD to HHD was loss of residual renal function. To the time of writing, no serious complications (including cardiovascular events and calcium homeostasis) had occurred. All patients continue to receive dialysis therapy and have been able to lead a nearly normal social life. Major laboratory findings include serum albumin 4.2 +/- 0.2 g/dL, hemoglobin 10.2 +/- 1.4 g/dL (half the patients were not using erythropoiesis-stimulating agents), serum creatinine 7.5 +/- 2.5 mg/dL, blood urea nitrogen 36 +/- 17 mg/dL, serum phosphate 4.3 mg/dL. In two thirds of the patients, blood pressure was controlled without antihypertensive agents. No patient had left ventricular hypertrophy. In this analysis, we found that relatively young subjects preferred PD first, with later transfer to HHD; that PD is superior as an introduction to dialysis therapy; that patients starting with PD prefer self medical treatment; and that all patients were free from the various complications that are encountered during long-term dialysis therapy. We suggest that patients who need dialysis therapy consider this new dialysis approach of "PD first and transfer to HHD."

The impact of pre-transplant dialysis modality on kidney transplant outcomes has been the impetus for many discrepant reports. Although candidacy for kidney transplantation may not necessarily be the main factor in deciding the choice of pre-transplant dialysis modality, certain complications are thought to be associated with one dialysis modality compared with the other and should be acknowledged. Most of the evidence to date, especially that for lower rates of delayed graft function, indicates an advantage for peritoneal dialysis (PD) over hemodialysis. More importantly, some groups of recipients clearly benefit more from receiving PD pre-transplant, a finding that was recently reported for high-risk adult recipients of expanded-criteria donor organs and pediatric recipients of living-donor organs. On the other hand, PD may be associated with a higher risk of early graft thrombosis. Moreover, the published literature highlights the need for caution in older candidates with a family history of diabetes mellitus because of potential higher risk for new-onset post-transplantation diabetes mellitus in PD patients. Interestingly, prospective studies validating those findings are scarce; most of the published reports have been limited by either small patient numbers or a lack of consideration of other confounding risk factors. In the present review, we examined the available literature related to the influence of pre-transplant dialysis modality on post-transplant allograft and recipient outcomes.

Peritoneal dialysis can be considered a "wearable" dialysis therapy. However, patients typically require 3 or 4 daily exchanges, each taking 20-40 minutes and potentially increasing the risk of infection by repeated disconnection and reconnection. Although peritoneal dialysis cyclers allow patients to be "free" from their machine for 13-15 hours, they similarly need a supply of fresh dialysate. Several groups have therefore explored the possibility of trying to minimize dialysate exchanges by recycling dialysate. However, that approach introduces not only a series of challenges, including regeneration of the spent dialysate, maintenance of acid-base and electrolyte balance and adequate ultrafiltration, but also new hurdles to be overcome, including monitoring the sorbents to determine when capacity is exceeded. The proposed Vicenza Wearable Artificial Kidney system consists of a continuous-flow peritoneal dialysis system that combines sorbents in series and urease to regenerate dialysate during the day, and a 7.5% icodextrin exchange overnight.

We set out to assess the effect of continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) on residual renal function (RRF) in children with end-stage renal disease (ESRD). In 101 children (age: 8.84 +/- 5.25 years; 44 on CAPD, 57 on APD) over 36 months, we evaluated RRF [as daily diuresis (DD) in mL/kg/24 h and mL/m2/24 h], glomerular filtration rate [GFR (in mL/min/1.73 m2)], ESRD cause, presence of arterial hypertension (HTN), biochemical parameters, peritoneal equilibration test (PET), adequacy [as total weekly Kt/V (twKt/V) and creatinine clearance (twCCr)], and infectious complications of PD. Initially, the CAPD and APD groups did not differ significantly in DD, but mean GFR was significantly higher in the APD group (p < 0.05). In the CAPD group, the volume of high osmolarity PD fluid was significantly lower (p < 0.05), and the rates of peritonitis and exit-site infection and of aminoglycoside use were higher (p < 0.001, p < 0.05, and p < 0.005 respectively). Over 36 months, the mean twKt/V and twCCr were within norms in both groups, but were higher in APD, significantly so (p < 0.05) for twKt/V at 24 and 36 months and for twCCr initially. In both groups, RRF decreased systematically, with a significantly lower (p < 0.05) rate of DD (mL/m2/24 h) and GFR decline in the first year in CAPD, but without a difference in the next 2 years. The longest RRF preservation was in children with tubulointerstitial nephropathies, particularly hypoplasia and dysplasia (p < 0.05). Children with hemolytic uremic syndrome (HUS) and hereditary nephropathy were at the highest anuria risk. Compared with the 22 children (7 CAPD, 15 APD) who became anuric, the 20 children (10 CAPD, 10 APD) with RRF preserved for 36 months had a higher DD and GFR before dialysis onset; higher hemoglobin and albumin; and lower HTN prevalence, cholesterol, triglycerides, and proteinuria (p < 0.05). Risk of anuria during 36 months did not differ significantly between the CAPD and APD groups. In children on CAPD or APD, risk factors for RRF loss include HUS, hereditary nephropathy, low diuresis and GFR before dialysis onset, HTN, anemia, hypoalbuminemia, hyperlipidemia, and proteinuria. Compared with children on APD, those on CAPD show better preservation of RRF during year 1, although the risk of anuria seems to be the same for both methods. In children with risk factors for rapid diuresis loss, CAPD might be considered the preferred initial dialysis method.

Peritoneal dialysis (PD) solutions are currently sterilized in an autoclave using high-temperature saturated steam. Although thermal methods are an effective means of sterilization, the heating of PD solutions results in the formation of toxic glucose degradation products (GDPs). Here, we review basic concepts in the sterilization of PD solutions and discuss possible alternatives to steam sterilization, including filtration, ohmic heat, ionizing radiation, and pulsed ultraviolet light. Although the latter methods have several advantages, many also have prohibitive limitations or have not been adequately studied for use on PD solutions. Thus, in the absence of suitable alternatives, conventional heat sterilization, in combination with low-GDP manufacturing practices, remains the best option at the present time.

The relationship between dialysis vintage (length of time on dialysis), body composition, and survival has been reported in hemodialysis patients. In the present study, we examined the association ofdialysis vintage with body composition and survival in peritoneal dialysis (PD) patients. At enrollment, body composition in 65 PD patients was determined by bioelectrical impedance analysis. Patients (mean age at enrollment: 54 years) were followed for up to 11 years maximum. At enrollment, the mean, median, and maximum dialysis vintages were 51, 34, and 261 months respectively. After adjusting for age, race, sex, and diabetes status, dialysis vintage was indirectly correlated (partial correlation coefficients) with body weight (r = -0.40, p = 0.001), body mass index (r = -0.40, p = 0.002), body surface area (r = -0.39, p = 0.002), body cell mass (r = -0.39, p = 0.002), total body fat weight (r = -0.30, p = 0.02), and fat percentage of body weight (r = -0.31, p = 0.018), and directly correlated with extracellular mass to body cell mass ratio (r = 0.27, p = 0.039). The observed cumulative survival was significantly higher (p = 0.007) in patients with a dialysis vintage at enrollment of 35 months or less, than in patients with dialysis vintage at enrollment of more than 35 months. In the multivariate Cox regression analysis, adjusting for age, race, sex, and diabetes, dialysis vintage at enrollment remained an independent predictor of mortality (relative risk: 1.010; p = 0.002). Increase in relative risk of death with increasing dialysis vintage may be partly explained by the association of vintage with unfavorable changes in body composition and the nutrition status of patients over time.