Nightly Intermittent Peritoneal Dialysis Research Articles

Effect of Peritoneal Dialysis Modality on the 1-Year Rate of Decline of Residual Renal Function

PurposeThe effect of different peritoneal dialysis (PD) modalities on the decline in residual renal function (RRF) is unclear due to inconsistencies among studies. In particular, the effect of automated peritoneal dialysis (APD) modalities [continuous cyclic peritoneal dialysis (CCPD) and nightly intermittent peritoneal dialysis (NIPD)] on RRF has not been examined in a large cohort.Materials and MethodsWe conducted a single-center retrospective study to investigate the association between PD modalities and decline in RRF in 142 incident PD patients [34 on CCPD, 36 on NIPD, and 72 on continuous ambulatory peritoneal dialysis (CAPD)]. RRF was measured within 2 months from PD start and at 1 year after PD initiation.ResultsThe RRF at 1 year after PD initiation was 1.98±2.20 mL/min/1.73 m2 in CCPD patients and 3.63±3.67 mL/min/1.73 m2 in NIPD patients, which were moderately lower than 4.23±3.51 mL/min/1.73 m2 in CAPD patients (p=0.064). Moreover, there was no significant difference in the 1-year rate of decline of RRF between CCPD and NIPD patients, although APD patients had a faster 1-year RRF decline rate than CAPD patients (CCPD and NIPD vs. CAPD: -45.68 and -36.69 vs. 1.17%/year, p=0.045). APD was associated with a more rapid decline in RRF in patients with end-stage renal disease undergoing PD, although multivariate analysis attenuated the significance of this finding (β=-31.50; 95% CI, -63.61 to 0.62; p=0.052).ConclusionOur results suggest that CAPD might be more helpful than APD for preserving RRF during the first year of dialysis therapy, although there was no significant difference in the 1-year rate of decline of RRF between the two APD modalities.

Die Peritonealdialyse bei Patienten mit Herzinsuffizienz oder Leberzirrhose – Hämodynamisch schonender als die intermittierende Hämodialyse

Peritoneal dialysis (PD) allows a gentle removal of fluid and uremic toxins as well as better mobilization of ascites. Therefore, PD is an important treatment option for patients with chronic heart failure as well as for those with liver cirrhosis. The fact that in PD patients neither an arteriovenous fistula (increased cardiac stress) nor implantation of a central venous catheter (risk of septicemia) is required has to be considered as an additional advantage for these patients. In patients with heart failure and moderately reduced renal clearance one single night-time dwell with icodextrin may provide adequate fluid removal. For intensification of PD, continuous ambulatory PD (CAPD), nightly intermittent PD (NIPD) and continuous cyclic PD (CCPD) are possible treatment options, whereas intermittent PD (IPD) performed in the center is associated with a less stable fluid balance. CAPD, NIPD and CCPD are also possible treatment options for patients with liver cirrhosis. Because of excellent peritoneal ultrafiltration and/or accumulation of ascites low glucose dialysate concentrations are usually required in these patients. Peritoneal protein loss in PD patients with liver cirrhosis decreases during the course of treatment in parallel with decline of ascites. The higher risk of gram-negative peritonitis in patients with markedly reduced liver function has to be considered. In patients with massive ascites tidal PD is the treatment of choice, since dialysate outflow during each PD cycle can be controlled. In both PD patients with heart failure and those with liver cirrhosis adequate adjuvant pharmacologic treatment should be optimized. Because of the high co-morbidity of both patient groups a helper is frequently required to perform successful home therapy. In future, assisted PD performed by home nurses may be an important treatment option for these patients.

Outcome and Survival in Different Peritoneal Dialysis Modalities

Peritoneal dialysis (PD) has been accepted as a treatment option for patients with end-stage renal disease, yet experience with PD in Arab countries is limited. This study was undertaken to evaluate the outcome and survival of different PD modalities. All patients managed at the Mubarak Al-Kabeer Hospital Kuwait between August 1982 and December 2003 using PD for three months or more were included in the study. Demographic features, outcome and survival of the patients were analyzed. Four hundred and fifteen patients with end-stage renal failure were admitted into the PD program. Their mean age was 52.06 +/- 16.43 years. Hospital-based intermittent peritoneal dialysis (IPD), continuous ambulatory peritoneal dialysis (CAPD), nightly intermittent peritoneal dialysis (NIPD) and continuous cycling peritoneal dialysis (CCPD) were preferred by 203 (48.9%), 176 (42.4%), 30 (7.2%) and 6 (1.4%) patients respectively. The mean duration of follow up was 12.7 +/- 11.7 months. Fifty-five (13.3%) patients were continuing on PD, 55 (13.3%) had shifted to hemodialysis, 73 (17.6%) underwent renal transplantation, 114 (27.5%) died, 34 (8.2%) returned to their native countries, 79 (19%) transferred to other centers and follow up was lost for 5 (1.45%) patients. Patient survival at two years was 56%, 72% and 87% in IPD, CAPD and NIPD respectively. Technique survival at two years was 60.6%, 75.4% and 100% in IPD, CAPD and NIPD respectively. Peritoneal dialysis modalities provide a feasible modality of renal replacement therapy. The overall outcome and patient and technique survival in home PD modalities were better than hospital-based PD.

Viability of Home Peritoneal Dialysis: Experience with 100 Patients from an Arab Population

The viability of home peritoneal dialysis (HPD) is being debated in Arab countries. We therefore undertook the present study to assess the viability of HPD in the Arab culture. A total of 100 patients with end-stage renal failure were treated with HPD during the period January 1996 to October 2001. Continuous ambulatory peritoneal dialysis (CAPD) was performed in 81 patients (81%), and nightly intermittent peritoneal dialysis (NIPD) in 19 patients (19%). The patient group included 54 men (54%) and 46 women (46%) with a mean age of 54.94 +/- 14.58 years. They were followed for a total of 2118.3 patient-treatment months and had a mean dialysis duration of 21.2 +/- 9.97 months. Peritonitis occurred at the rates of 1 episode every 18.5 patient-treatment months (Bieffe L3 double-bag system: Bieffe Medital, Grosotto, Italy), 1 episode every 22.5 patient-treatment months (ANDY Plus system: Fresenius Medical Care, Bad Homburg, Germany), and 1 episode every 23.7 patient-treatment months (NIPD system Fresenius PD-Night: Fresenius Medical Care, Bad Homburg, Germany). Recurrent peritonitis was the main reason (70.6%) for transfer to hemodialysis. A good level of social well-being and rehabilitation was achieved in 49 patients on CAPD (60.5%) and 13 patients on NIPD (68.4%). We conclude that HPD is a viable modality of renal replacement therapy in Arab countries. By adopting a strict training model, the peritoneal dialysis team can train even patients or caregivers with limited education, preventing peritonitis and promoting the general well-being of patients.

Continuous Flow Peritoneal Dialysis: Assessment of Fluid and Solute Removal in a High-Flow Model of “Fresh Dialysate Single Pass”

♦ Background Growing concern over the limited capacity of the peritoneal dialysis (PD) system has revived interest in continuous flow peritoneal dialysis (CFPD), a modality in which continuous circulation of PD fluid is maintained at a high flow rate using two separate catheters or one dual-lumen catheter. The CFPD regimen contrasts the “inflow/outflow” regimen, which requires specific times devoted to filling and draining the peritoneum via a single-lumen catheter. Historical data established CFPD capabilities in providing higher solute clearance and ultrafiltration rate (UFR) using either an open loop system with a single pass of fresh PD fluid, or various external purifications of the spent dialysate. ♦ Objective To compare, in patients with various peritoneal transport patterns, fluid and solute removal achieved during a standardized program of CFPD versus two control schedules: nightly intermittent peritoneal dialysis (NIPD) and nightly tidal peritoneal dialysis (NTPD). This study focused on small solute clearances and UFR using only isotonic PD solution (Dianeal PD1 1.36%; Baxter Healthcare, Castlebar, Ireland). The model of fresh dialysate, single pass, was used to optimize solute gradients and to characterize the impact of a continuous flow regimen on peritoneal transport characteristics. ♦ Methods In a crossover trial, 4-hour CFPD sessions were performed at a fixed dialysate flow rate (100 mL/minute) in 5 patients being treated with automated PD. A hemofiltration monitor (BM25; Baxter Healthcare, Brussels, Belgium) was adapted to the CFPD technique. The peritoneal cavity was filled through a temporary second catheter and simultaneously drained using the permanent peritoneal access. Fluid and solute removal were compared to data obtained from a control period based on 8-hour sessions of NIPD or NTPD using 13 L of isotonic dialysate. ♦ Results High-flow CFPD enhanced the diffusive transport coefficient compared with the alternative flow regimen in patients ranging from low to high transporters. Weekly creatinine clearance increased from 36.9 L (22.3 – 49.6 L) and 37.3 L (27.5 – 45.0 L) with NIPD and NTPD respectively, to 74.9 L (42.3–107.5 L) with CFPD. Mean UFR was 2.44 mL/min with CFPD versus 0.92 and 0.89 mL/min with NIPD and NTPD respectively. The mass transfer area coefficient (MTAC) of creatinine with CFPD was 2.5-fold that obtained from the peritoneal equilibration test data. ♦ Conclusion Our results confirm that CFPD is highly effective in increasing fluid and solute removal. Furthermore, consistent with historical data, our findings indicate that the enhanced solute transfer is not due only to steeper solute gradients, but also depends on increased MTAC in a wide range of peritoneum transport characteristics.

Middle molecule and small protein removal in children on peritoneal dialysis

Dialysis efficiency has a great influence on the outcome of patients. Few data are available on the removal of solutes with molecular weights higher than urea and creatinine. The aim of our study was to assess the transport and the removal of substances with molecular weights up to 15 kD and to evaluate the contribution of residual renal function in peritoneal dialysis (PD) children. Seventeen patients of 12 +/- 4 years undergoing automated PD were studied. Ten patients had 563 +/- 355 mL/day of urine output, and 7 were anuric. During a standardized nightly intermittent PD (NIPD) session, a single-injection inulin clearance was performed. Urea, creatinine, inulin (measured by HPLC), cystatin C and beta2-microglobulin (beta2m) were measured in blood, urine and dialysate. Clearances (L/week/1.73 m2) and weekly solute removal index (SRI) were calculated for all the solutes; weekly Kt/V was calculated for urea. In non-anuric versus anuric patients the total clearances were: urea 82.6 +/- 18.3 versus 71.3 +/- 26.4; creatinine 82.7 +/- 28.6 versus 47.8 +/- 18.8; inulin 42.8 +/- 11.3 versus 32.8 +/- 20.4; beta2m 14.2 +/- 13.8 versus 9.2 +/- 8.3; cystatin C 20.2 +/- 9.4 versus 9.7 +/- 4.8. In the patients with residual diuresis, the urea was removed mainly by PD (69.2%), while inulin, beta2m and cystatin C were removed by renal clearance (64.0%, 79.5% and 62.8%, respectively). Total, peritoneal and renal weekly Kt/V values in the subjects with residual renal function, were 2.86 +/- 0.70, 1.99 +/- 0.40 and 0.87 +/- 0.43, respectively. Peritoneal weekly Kt/V in the anuric patients was 2.36 +/- 0.85; total weekly Kt/V in the total group was 2.65 +/- 0.78. Weekly SRIs in non-anuric versus anuric patients were: urea 2.56 +/- 0.58 versus 2.09 +/- 0.74; creatinine 2.66 +/- 0.73 versus 1.46 +/- 0.56; inulin 2.36 +/- 0.92 versus 1.64 +/- 1.60; beta2m 1.26 +/- 1.10 versus 1.20 +/- 1.90; cystatin C 1.72 +/- 0.83 versus 1.58 +/- 1.62. Solutes removed during PD tend to decrease following an increase in molecular weight of the substance. Since anuric patients are at higher risk of middle molecule and small protein accumulation, more attention should be paid to the removal of middle molecules. Further studies should be undertaken to evaluate whether removing them has a clinical impact and to determine their threshold levels.

Effects of dialysate volume and flow on solute and water removal with different peritoneal dialysis schedules.

There exist both a strong rationale and convincing surface area rather than to total body water. Also, the evidence that the minimum weekly Kt/V urea should renal contributions of creatinine clearance are usually be 2.0 in continuous ambulatory peritoneal dialysis estimated as creatinine clearance solely by glomerular (CAPD) patients [1‐12]. In this same issue, I have filtration rate. This is calculated as the mean of renal presented arguments for initiating dialysis and main- urea and creatinine clearances. Also, if creatinine cleartaining a peritoneal dialysis prescription so that the ances are to be used for prescription modelling, then weekly Kt/V urea with continuous peritoneal dialysis attention must be paid to the corrections for glucose does not fall below 2.0. The weekly Kt/V urea for interference on creatinine concentrations in the nightly intermittent peritoneal dialysis (NIPD) should dialysate. be slightly higher than that for CAPD since NIPD is If the numerator of the Kt/V urea remains constant, intermittent and there are fluctuations in serum urea than Kt/V urea decreases as V increases [12‐15]. We nitrogen concentrations. Such recommendations are previously have published the Kt/V urea expected in based on the assumption that the control of peak anephric patients using various peritoneal dialysis cycle serum urea nitrogen concentration is important for times and exchange volumes, and have also shown control of uraemic symptoms and that at the same those standard body weights at which the clearances urea nitrogen generation rate, an intermittent therapy with each plan fall below recommended targets [14,15]. requires greater clearance than a continuous therapy The rate at which small solutes approach equilibrium to maintain the serum urea nitrogen concentration at across the peritoneal membrane markedly influences or below the steady-state value of the continuous the clearance achieved with given cycle times [16‐18]. treatment [13]. Here I will summarize approaches The peritoneal dialysis equilibration test is very helpful to maintaining target levels for peritoneal dialysis in defining the type of membrane transport that a treatment. patient has and in predicting various clearances at given cycle times [16 ].

Effect of Dialysis Modality and Membrane Transport Characteristics on Dialysate Protein Losses of Patients on Peritoneal Dialysis

To determine if peritoneal dialysis modality has an impact on protein losses in dialysate. Retrospective, cross-sectional study. 190 patients who had selected peritoneal dialysis were classified into one of four transport categories (high, high-average, low-average, or low) based on standard peritoneal equilibration test results. Patients were then assigned to continuous ambulatory peritoneal dialysis (CAPD) or nightly intermittent peritoneal dialysis (NIPD) based on membrane transport characteristics and individual preferences. Patients with similar membrane transport characteristics had essentially no differences in dialysate protein and albumin losses whether treated with CAPD or NIPD. Although high transporters may be better managed with short-dwell therapies such as nocturnal intermittent peritoneal dialysis or daily ambulatory peritoneal dialysis, consistent marked decreases in protein losses cannot be cited as a benefit of NIPD over CAPD.

Adequate Dialysis? Measurement of Ktn in a Pediatric Peritoneal Dialysis Population

To measure the urea and creatinine kinetics in a pediatric population. In 19 children treated with peritoneal dialysis (PD) KT/V, urea and creatinine clearances (Ccr) were measured. Thirteen children were on continuous ambulatory peritoneal dialysis (CAPD) and 6 on highly intermittent peritoneal dialysis (NIPD). Mean KT/V per week was 2.31 +/- 0.78 and mean creatinine clearance 74 +/- 47 L/week/1.73 m2. There was no difference in dialytic KT/V between patients treated with CAPD and NIPD (1.75 +/- 0.21 vs 1.76 +/- 0.50). The correlation between KT/V urea and creatinine clearance was 0.9 (p < 0.001). There was a clear relationship of these parameters with residual renal function, but not with age or blood urea level. A weak positive correlation was found with serum albumin and protein intake. Mean KT/V in this patient group was higher than the values reported for most adult patient groups. Residual renal function considerably contributes to this high KT/V. It is not clearly defined which KT/V should be aimed for, since criteria for adequate dialysis are multifactorially determined and therefore difficult to interpret.

Rapid Decline of Residual Renal Function in Patients on Automated Peritoneal Dialysis

To determine the effect of peritoneal dialysis modalities such as nightly intermittent peritoneal dialysis (NIPD), continuous cyclic peritoneal dialysis (CCPD), and continuous ambulatory peritoneal dialysis (CAPD) on residual renal function. A six-month prospective, nonrandomized comparison study. Outpatient CAPD unit of a university hospital. Eighteen end-stage renal disease patients treated by peritoneal dialysis (8 by NIPD, 5 by CCPD, and 5 by CAPD). Samples from the total dialysate, blood, and 24-hour urine collection were obtained monthly. Urea, creatinine, and beta2-microglobulin concentrations were measured. Renal and peritoneal clearances of each substance and KT/V urea were calculated. Residual renal function (RRF) was estimated by renal creatinine clearance (RCcr). No significant differences in age, sex, and primary renal disease among the three groups were noted. In all groups, anemic and hypertensive states were controlled identically, and mean weekly total (renal + peritoneal) KT/V urea (over 2.1/wk) and total creatinine clearance (over 60 L/wk/1.73 m2) were maintained during the whole experimental period. Starting mean RCcr was near 4.0 mL/min/1.73 m2 in all groups. Thereafter, a rapid and significant decline in RRF was demonstrated on NIPD and CCPD. The declining rates of RCcr values at 6 months after starting NIPD and CCPD were -0.29 and -0.34 mL/min/month, respectively, which were much greater than those of CAPD (+0.01 mL/min/month). Because of a possibly characteristic progressive loss of RRF in automated peritoneal dialysis (APD), strict regular assessment of RRF should be performed from the start of APD.

How to Reach Optimal Creatinine Clearances in Automated Peritoneal Dialysis

This paper summarizes the basis of prescription for automated peritoneal dialysis (APD) established during a French national conference on APD. Clinical results and literature data show that peritoneal clearances are closely determined by peritoneal permeability and hourly dialysate flow rate, independently of dwell time or number of cycles. With APD, peritoneal creatinine clearance increases according to the hourly dialysate flow rate to a maximum (plateau), then decreases because of the multiplication of the drain-fill times. The hourly dialysate flow giving the maximum peritoneal creatinine clearance is defined as the "maximal effective dialysate flow" (MEDF). MEDF is higher for high peritoneal permeabilities: MEDF is 1.8 and 4.2 L/hr with nocturnal tidal peritoneal dialysis (TPD) for a 4-hr creatinine dialysate-to-plasma ratio (D/P) of 0.50 and 0.80, respectively. With nightly intermittent peritoneal dialysis (NIPD), MEDF is 1.6 and 2.3 L/hr for a D/P of 0.50 and 0.78, respectively. Under these conditions, tidal modalities can only be considered as a way to increase the MEDF. Using the MEDF concept for an identical APD session duration, the maximal weekly normalized peritoneal creatinine clearance can vary by 340% when 4-hr D/P varies from 0.41 to 0.78. APD is not recommended when 4-hr creatinine D/P is lower than 0.50. However, the limits of this technique may be reached at higher peritoneal permeabilities in anurics because of the duration of sessions and/or the additional exchanges required by these patients.

Evaluation of the Peritoneal Equilibration Test in Children on Chronic Peritoneal Dialysis

The peritoneal equilibration test (PET) is routinely performed in adults treated with chronic peritoneal dialysis to assess the peritoneal transport rate and to optimize treatment prescription. Only a few and not well-standardized studies on the PET have been reported in children. Twenty-six PET's were performed in 16 children, mean age 10.9 +/- 4.9 years, mean body weight (BW) 26.8 +/- 11.9 kg, treated with nightly intermittent peritoneal dialysis (NIPD). The PET was performed according to Twardowski. Forty mL/kg BW of 2.27% glucose solution were infused at a rate of 10 mL/kg BW every 2 minutes. In the simplified test, dialysate samples were taken at dwell times 0, 2 and 4 hours for glucose and creatinine. A blood sample was taken after a 2-hour dwell time for the same parameters. The standard PET (8 patients) consisted of dialysate samples at 0, 15, 30, 60, 120, and 240 minutes and blood samples at 0 and 240 minutes. Mean D/P ratio for corrected creatinine and D/D0 ratio for glucose at 2 hours were 51.6 +/- 11.6 and 50.4 +/- 9, respectively; at 4 hours 69.6 +/- 12 and 34.4 +/- 9.8, respectively. There was good correlation between D/P creatinine and D/D0 glucose at 4 hours (p < 0.0001). Patients were classified as high (3 cases), high-average (5), low-average (6), and low (2) transporters. A statistically significant difference was found between the curves obtained by the simplified PET and those of the standard PET in the first hour (r = 0.66; p < 0.05). In conclusion, the PET, modified for use in children, gave reliable and reproducible results.(ABSTRACT TRUNCATED AT 250 WORDS)

Weekly Clearances of Urea and Creatinine on CAPD and NIPD

Weekly creatinine clearance (Ccr) and weekly Curea/v (kt/v) are popular indices for quantitating the amount of peritoneal dialysis provided. Studies were undertaken on 44 patients on continuous ambulatory peritoneal dialysis (CAPD) and 10 patients on nightly intermittent peritoneal dialysis (NIPD) to compare relationships of weekly creatinine clearance to weekly urea clearance (Curea) divided by total body water (v). With a long cycle therapy such as CAPD, the ratio of weekly Ccr to weekly kt/v is higher than with a short cycle technique, such as NIPD, in the same patient. If patients are shifted from CAPD to NIPD maintaining the same weekly kt/v, the weekly Ccr will decrease. If patients are shifted from CAPD to NIPD maintaining the same weekly Ccr, then the weekly kt/v will increase. The clinical implications of these observations are unknown, but should be kept in mind for future studies comparing CAPD and NIPD.