Incremental peritoneal dialysis: effects on the choice of dialysis modality, residual renal function and adequacy.

There is still disagreement on whether peritoneal dialysis (PD) should begin with a full dose (Full_Dial) or with incremental doses (Incr_Dial) to compensate for the amount of Kt/V no longer supplied by the residual renal function (RRF). The aim of this study is to assess the effects of an Incr_Dial protocol on the choice of dialysis modality, RRF, and adequacy. The Incr_Dial protocol in our center is as follows: for patients with a glomerular filtration rate (GFR)>5 ml min(-1), PD is initiated with two exchanges per day (continuous ambulatory PD (CAPD)) or four sessions per week (ambulatory PD (APD)); and hemodialysis (HD) is initiated with two sessions per week. The PD dose is then increased in proportion to the reduction in the GFR as follows: GFR< or =5 and >3 ml min(-1)=3 CAPD exchanges or five APD sessions; GFR <3 ml min(-1)=full dialysis dose (Full_Dial). The effects of the Incr_Dial protocol on the choice of dialysis modality were assessed on 87 patients (pts) (age: 69.3+/-13.1 years) who initiated dialysis between 1 January 2004 and 31 May 2007. The effects of Incr_Dial on RRF and dialytic adequacy were assessed in 11 pts treated with two CAPD exchanges per day for a total of 106 months (mean+/-s.d. 9.7+/-6.5), and then treated with three CAPD exchanges per day for an additional 105 months (9.4+/-8.3). The use of Incr_Dial determined the choice of PD in 27 of 44 pts (61.4%) without indications or contraindications to HD or PD. CAPD was chosen by 20 of these pts (74.1%), whereas APD was preferred by 6 of the 8 pts switched from Incr_Dial to Full_Dial. During Incr_Dial, a significant reduction in the loss of GFR of 2.4+/-3.1 ml min(-1) year(-1) was observed when compared to the pre-dialysis period. Incr_Dial allowed for adequate clearance, as confirmed by the Kt/V (2.07+/-0.2), protein nitrogen appearance (1.17+/-0.13), and biochemical parameters. Ultrafiltration (UF) with icodextrin (772+/-166 ml per exchange) provided a daily UF of 517+/-296 ml day(-1) and remained unchanged when the duration of the dwell time increased significantly from 12.3+/-1.4 to 17.5+/-2.6 h.

[Improving the outcome of peritoneal dialysis in the long term: is it possible?]. / E possibile migliorare gli outcome a distanza della dialisi peritoneale?

Improving the results of peritoneal dialysis (PD) over time means reducing both the technique's drop out (TDO) and mortality rates. The PD mortality rate has diminished over the years, due to greater experience in using the technique and the reduction in mortality due to peritonitis making it comparable with the hemodialysis (HD) mortality rate. Moreover, improved control of the hydrosaline balance through the use of ambulatory peritoneal dialysis (APD) and icodextrin could further improve the survival rate in the future. The adequacy targets needed to reduce the mortality rate still appear to be debatable, as their importance seems conditioned by the presence of RRF and comorbidity. The TDO is higher in PD than in HD because PD is a self-administered treatment that uses a biological membrane as a filter. The most frequent causes of TDO are peritonitis (30-40%), dialytic inadequacy (11-27%), and subsequent inability and/or choice (10-32%). Peritonitis is the cause that has seen the greatest reduction over time due to the introduction of the Y-Set, but a further reduction could result from the prevention of ESI, and from improvements in the patient selection procedure designed to identify both clinical and psycho-social disposition peritonitis risk factors. Among the causes of TDO due to dialytic inadequacy, insufficient ultrafiltration (UF) could benefit from the diffusion of APD and icodextrin, while insufficient depuration could be reduced by new targets and optimization of the prescription. Finally, TDO due to social causes could be reduced by the use of APD, care support and appropriate patient selection.

[Homocysteine, folate therapy and outcome in hemodialysis: results from a prospective study]. / Omocisteina, terapia con folati e prognosi in emodialisi: domande e risposte da uno studio prospettico monocentrico.

BACKGROUND: Despite the well-known effectiveness of folate therapy on hyperhomocysteinemia in hemodialysis, its benefits on outcome are still unclear. METHODS: Sixty-five patients on thrice-weekly maintenance hemodialysis lasting more than 3 months were followed up for 1 year after stratification by predialysis homocysteine level (tHcy). Parenteral folate (25 mg quarterly) and cobalamine (1 mg quarterly) therapy was started only if the tHcy levels were > 30 uM/L at baseline or at scheduled retests (every 7 months). End points were overall mortality and new ischemic events (affecting heart, brain, or lower extremities). RESULTS: 58.5% of patients received treatment at baseline and achieved a 60% reduction of tHcy. 38.1% progressed to levels of over 30 tHcy at 6 months and were placed on treatment. No other major changes occurred until the end of the study. An excess of both overall mortality (30.8% versus 12.1%; p = 0.075) and vascular morbidity (38.5% versus 12.1%; p = 0.03) occurred in initially untreated patients,those presenting without baseline intermediate to severe hyperhomocysteinemia. CONCLUSIONS: In undertaking hemodialysis, it appears that treating intermediate to severe hyperhomocysteinemia carries better prognosis for outcome than untreated moderate or absent hyperhomocysteinemia. It is uncertain if the benefit of therapy is valid, or if it is confounded by an association between lower tHhy and hidden malnutrition or concomitant diseases.

Evaluation of drainage times and alarms with various automated peritoneal dialysis modalities.

This paper assesses the variation in total drainage time (TDT) and number of alarms due to low drainage volume (LDV) in automated peritoneal dialysis (APD) patients with varying catheter performance. Catheter performance was measured by drainage break point (DBP) in a supine position. Six patients with DBP > or = 80% underwent three types of APD: non tidal, 50% tidal, and 80% tidal. Six patients with DBP < 70% underwent two types of APD: non tidal and tidal fixed at 5% below DBP. In every case, the fill volume was 2.3 L. For the purpose of the study, each treatment was continued for seven consecutive nights. Home Choice Pro (Baxter Healthcare Corporation, Deerfield, Illinois, U.S.A.) was used to calculate the TDT and LDV. With both the non tidal and tidal treatments, TDT was higher in patients with DBP < 70% as compared with patients with DBP > or = 80%. In the latter group, 50% tidal was the most effective technique in reducing TDT. In patients with DBP < 70%, the tidal treatment reduced not only TDT, but also LDV alarms, as compared to the non tidal treatment. In conclusion, choosing the tidal method helps to reduce LDV alarms and TDT, especially in patients with a low DBP. The Home Choice Pro device is an effective aid in setting up and assessing the dialytic prescription.

Ultrafiltration with icodextrins in continuous ambulatory peritoneal dialysis and automated peritoneal dialysis.

Icodextrins (Icos) produce constant linear ultrafiltration (UF). This effect allows Icos to replace glucose during long dwells in continuous ambulatory peritoneal dialysis [CAPD (nighttime)] and automated peritoneal dialysis [APD (daytime)]. However, the effectiveness of Icos in producing UF (IcoUF) is limited by lymphatic reabsorption, whose extent depends partly on posture and physical activity. This paper aims to assess whether the difference in posture and physical activity between daytime dwells in APD and nighttime dwells in CAPD affects IcoUF. Patients undergoing first treatment were retrospectively examined. Ten patients were on CAPD [4 males, 6 females; average age, 73.0 +/- 13.4 years; body surface area (BSA), 1.63 +/- 0.21 m2; total volume per day, 5.6 +/- 1.9 L], and ten were on APD (7 males, 3 females; average age, 67.7 +/- 9.8; BSA, 1.75 +/- 0.22 m2; total volume per night, 10.5 +/- 0.9 L). Ultrafiltration was assessed for seven consecutive days preceding a peritoneal equilibration test (PET) and collection of diuresis. In both groups, 3 patients had no diuresis, and the difference between CAPD and APD was not significant (625 +/- 762 mL vs 780 +/- 878 mL). Moreover, no significant difference was seen in 4-hour dialysate-to-plasma creatinine (D/P) between CAPD (0.65 +/- 0.12) and APD (0.64 +/- 0.05). Dwell times with Icos were shorter in CAPD than in APD (11.5 +/- 1.8 hours vs 14.8 +/- 0.5 hours, p < 0.0005), but the fill volume was not significantly different (1760 +/- 286 mL vs 1790 +/- 249 mL). Water excretion owing to diuresis and dialysis [total water excretion (TWE): 1619 +/- 497 mL CAPD vs 1762 +/- 736 mL APD] and dialytic UF (363 +/- 443 mL CAPD vs 748 +/- 479 mL APD), which is not linked to Icos, were not significantly different between the two groups. The IcoUF and the percentage of IcoUF to TWE were significantly higher in CAPD compared to APD [631 +/- 253 mL (44% +/- 27%) vs 234 +/- 215 mL (19% +/- 19%), p < 0.001 (p < 0.05)]. In conclusion, an upright posture and physical activity seem to produce less IcoUF in APD despite the longer dwell. These factors could, indeed, produce greater intraperitoneal pressure, resulting in increased lymphatic reabsorption during a daytime dwell.

Calculation of Kt/V and creatinine [correction of creatine] clearance in APD.

The calculation of Kt/V and creatinine clearance per 1.73 m2 of body surface area (CrCl/1.73 m2 of BSA) varies according to whether the post- or pre-nightly dialysis treatment (NDT) values of the serum urea (sUrea), serum creatinine (sCreat), and body weight (BW) parameters are used. The purpose of this paper is to determine the difference between Kt/V and CrCl/1.73 m2 of BSA, calculated using the pre- and post-NDT values, and any correlation of such differences with different automated peritoneal dialysis (APD) methods. We took into consideration patients on APD treated using the tidal method with four different techniques: NTPD (9 patients; no daytime dwell), NTPD-1 (12 patients; one daytime dwell of 4-7 hours), CTPD (10 patients; one daytime dwell), and CTPD-2 (8 patients; two daytime dwells). Body water (V) and body surface area (BSA) were calculated using the Watson and Du Bois formulas. The percentage difference between pre- and post-NDT using the various methods is not statistically significant, while all the post-NDT parameters are significantly lower than the pre-NDT parameters. Since this difference is greater for sUrea (8.8%) and V (1.1%) than for sCreat (4.1%) and BSA (0.8%), the nightly Kt/V variation (11.2%) is greater than the nightly CrCl/1.73 m2 of BSA variation (5.2%). These variations do not differ significantly among the various methods. For APD, therefore, increase is to be expected in the CAPD targets of 10% and 5% respectively for Kt/V and CrCl/1.73 m2 of BSA calculated using the post-NDT values of sUrea and sCreat and the pre-NDT value of BW.

Information technology in a dialysis department.

The use of information technology in a peritoneal dialysis service, as in any facility, poses the problem of the choice of the data to be stored. It is important to define the whole range of information which may be of use and to assess the costs and benefits involved. These will depend on how complete and reliable the stored information is, how well the management process (filing and processing) is integrated with its day to day use by the Department. It is essential to both safeguard work efficiency and guarantee processing which will be useful in routine operations, including checking the quality of work carried out, and in study and research.

Prevalence of hyperlipidemia in a cohort of CAPD patients. Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG).

An association between hyperlipidemia and cardiovascular disease is well described in the literature. We conducted an observational study in order to evaluate the lipid profile, the prevalence of hyperlipidemia and its relationship with age, sex, duration of CAPD, peritoneal glucose load (PGL), serum albumin (ALB), serum glucose (GLU), and BMI in a large cohort of uremics undergoing long-term treatment with CAPD. 457 nondiabetic patients (245 males, 212 females; mean age 63.8 +/- 11.9 years; mean duration of CAPD: 41.8 +/- 26.9 months) treated during 1992 in 25 centers participating in the Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG) were studied. The serum lipid parameters evaluated were triglycerides (TG), total cholesterol (CHO), HDL-cholesterol (HDL). Indications given in the New England Journal of Medicine, SI Unit Conversion Guide, 1992, were adopted for normal ranges. In the whole population the evaluation of lipid parameters showed: TG 227.4 +/- 123.3 mg/dl, CHO 232.8 +/- 56.0 mg/dl, HDL 40.7 +/- 12.0 mg/dl. No differences were found between the two sexes with regard to age, BMI, duration of CAPD, distribution of renal diseases, TG, ALB, and GLU; whereas CHO and HDL were significantly lower in males than in females (CHO: 222.2 +/- 53.5 vs. 245.0 +/- 56.5 mg/dl, p < 0.001; HDL: 39.3 +/- 11.4 vs. 42.6 +/- 12.6 mg/dl, p < 0.05). The prevalence of hypercholesterolemia was significantly lower in males than in females (19.7 vs. 35.4%; p < 0.001). The multiple regression analysis indicated that TG were directly correlated to PGL (p < 0.05), and HDL was inversely correlated with TG (p < 0.001). The coexistence of the two variables (TG and HDL) may increase the risk of cardiovascular events. Further strategies should therefore be developed to select and manage CAPD patients to reduce the incidence of hyperlipidemia.

Compliance study in peritoneal dialysis using PD Adequest software.

Poor compliance in peritoneal dialysis (PD) is a significant cause of dropout and morbidity. PD Adequest software, which, through a mathematical model, predicts the effect of the dialysis prescription on the basis of the peritoneal transport, may be used to identify the noncompliant patient. Fifty patients from two dialysis centers, aged 65.9 +/- 1.5 years and on PD for 28.6 +/- 4.7 months, were studied. A peritoneal equilibration test (PET) was carried out and 24-hour urine and dialysate were collected. Total weekly creatinine clearance (CrCl, L/week/1.73 m2) was calculated, as well as the glomerular filtration rate [(GFR), mL/min, mean CrCl and urea nitrogen clearance (UNCI)]. The dialytic schedules used were then introduced into the program and the parameters were recalculated using the software model. Nine patients considered noncompliant from their case histories were used to assess the differences of reference between expected and measured values. The control group was significantly different from the noncompliant group in the percentage of the CrCl and the serum creatinine (sCR) differences. The noncompliance threshold value was calculated from the mean of the lower 95% confidence interval of the compliant group and the higher one of the noncompliant group (-5.3%) for CrCl and vice versa for sCR (+10%), which behaved to the contrary. Reassessing the patients, 11 (22%) were identified as probably noncompliant.

Normalization of protein equivalent of nitrogen appearance and dialytic adequacy in CAPD.

Caloric-proteic malnutrition is frequently encountered in peritoneal dialysis and is associated with an increased risk of morbidity and mortality. Our paper aims to assess any greater reliability of protein equivalent of nitrogen appearance (PNA) normalization to desirable body weight (dBW) compared to actual body weight (aBW) and resulting implications for the relationship between dialytic adequacy and protein intake in continuous ambulatory peritoneal dialysis (CAPD). We studied 36 patients on CAPD, 24 male and 12 female (aged 66.6 +/- 10.2 years, 24 +/- 29 months on dialysis), collecting dialysate and urine over 24 hours (126 samples) to calculate the PNA according to Randerson and the total weekly KT/V. The total body muscle mass (TBMM) was calculated by anthropometry and the dBW according to Metropolitan Life Insurance tables. Finally, PNA was normalized to aBW (aPNA, g/kg/day) and to dBW (dPNA, g/kg/day). Average aBW proved to be higher than dBW (66.0 +/- 11.1 vs 59.8 +/- 6.9 kg, p < 0.0001) and aPNA lower than dPNA (0.96 +/- 0.31 vs 1.08 +/- 0.3 g/kg/day, p < 0.005). Compared to aPNA, dPNA correlates better with both blood urea nitrogen (BUN) (R2 = 0.702 vs 0.614) and KT/V (R2 = 0.348 vs 0.306). The TBMM is higher in the group with dPNA > or = 1.0 vs < 1.0 g/kg/day (25.5 +/- 0.6 vs 23.1 +/- 0.7 kg, p < 0.02) while, paradoxically, it is lower in patients with aPNA > or = 1.0 vs < 1.0 g/kg/day (22.8 +/- 0.8 vs 25.4 +/- 0.6 kg, p < 0.01). The KT/V of the patients with dPNA < 0.8, 0.8-1.2 and > 1.2 g/kg/day proved to be different (1.52 +/- 0.06 vs 1.80 +/- 0.03 vs 2.04 +/- 0.04, p < 0.005). On analysis of the linear regression, dPNA = 1.0 and 1.2 g/kg/day corresponds to KT/V values of 1.7 and 2.05, respectively. We consider dPNA to be more suitable then aPNA for the correct assessment of protein intake, and a weekly KT/V of 1.7-2.05 as being sufficient to guarantee satisfactory dPNA.

Cross-sectional comparison of malnutrition in continuous ambulatory peritoneal dialysis and hemodialysis patients.

Although malnutrition is not uncommon in continuous ambulatory peritoneal dialysis (CAPD) and maintenance hemodialysis (MHD) patients, there has never been a large-scale comparison study of nutritional status with these two dialysis modalities. We therefore assessed protein-calorie nutrition in 224 CAPD patients and 263 MHD patients who were treated in eight centers in Italy. The CAPD patients were slightly older than the MHD patients (60.2 +/- 14.2 years v 56.3 +/- 15.1 years; P < 0.01), had undergone dialysis for less time (2.32 +/- 2.10 years v 3.66 +/- 2.66 years; P < 0.0001), and had higher residual renal function (1.83 +/- 2.29 mL/min v 0.27 +/- 0.91 mL/min; P < 0.0001). Protein nitrogen appearance was 60.5 +/- 16.6 g/d and 61.9 +/- 16.5 g/d in the CAPD and MHD patients, respectively. In CAPD versus MHD patients, serum total protein and albumin tended to be lower; serum transferrin and midarm muscle circumference were similar; and relative body weight, skinfold thickness, and estimated percent body fat tended to be greater. These greater values in CAPD patients were particularly evident in those who were 65 years of age or older. Serum glucose, total cholesterol, and triglycerides also were greater in CAPD patients. The subjective global nutritional assessment indicated a significantly greater proportion of malnourished CAPD patients than MHD patients (42.3% v 30.8%). The greater prevalence of malnutrition in CAPD patients diminished with age. Maintenance hemodialysis patients older than 76 years were more likely to be malnourished than CAPD patients. In patients less than 65 years of age, protein-calorie malnutrition was more likely to be present in CAPD patients than in MHD patients.

Role of automated peritoneal dialysis within a peritoneal dialysis program.

We wished to assess the impact of automated peritoneal dialysis (APD) on the peritoneal dialysis (PD) program. From November 1981 to December 1993, 112 patients were started on hemodialysis (HD) as first treatment and 88 on PD [continuous ambulatory peritoneal dialysis (CAPD): 78, APD: 10]; respective average ages were 61 +/- 14 and 62 +/- 13 years. To December 1985, APD was used as first treatment of PD in 1/29 patients (3.4%), while subsequently, on the basis of a clinical and social-aptitude assessment protocol, it was used in 9/59 patients (15.2%) with PD indication and CAPD contraindications (work: 2 patients, partner required: 7 patients). Of the patients who interrupted CAPD, APD was used in 9/21 patients (reason: social aptitude, 28.6%; clinical, 71.4%). Technique survival after 5 years proved no different in HD versus PD (87% vs 82%, p = NS), whereas in HD versus CAPD it was different (87% vs 62%, p < 0.025). The incidence of peritonitis in APD and CAPD with the Y-set was comparable (1/37 vs 1/40 episode/patient-months), while germ distribution was different (p < 0.001) with Staphylococcus epidermidis prevailing in APD (59%). Based on our experience, APD may extend method acceptance criteria and reduce the technique dropout rate in PD; however, connection technique may need to be improved in order to reduce the risk of peritonitis from exogenous contamination.

Hematocrit has no effect on peritoneal transport indices.

To assess the effect of hematocrit (Hct) on peritoneal transport indices (PTi), we studied the relationship between Hct (mean 28.1 +/- 5.1%, range 19.1-41.3%) and PTi with 118 peritoneal equilibration tests (PETs; 270 min, 1.36%) on 52 stable patients on peritoneal dialysis. Furthermore, considering a Hct 30% as ideal in peritoneal dialysis (PD), 14 patients who had performed a PET both with a Hct <30% and > or = 30% were checked for any variations in the PTi and blood pressure. We analyzed the subsequent PTi: ultrafiltration; creatinine (Cr) and blood urea nitrogen (BUN) clearance and mass transfer area coefficient (MTAC); 120, 240, and 270 min Cr D/P, UN D/P and glucose D/D0. Linear regressions between Hct and the PTi (118 PETs) did not prove statistically significant. The analysis of the PTi in 14 patients who had performed a PET with both a Hct < 30% and > or = 30% did not prove statistically significant, and no change in blood pressure was demonstrated. We do not consider Hct to have a significant influence on PTi.

Long-term outcome in continuous ambulatory peritoneal dialysis: a 10-year-survey by the Italian Cooperative Peritoneal Dialysis Study Group.

Over a 10-year period, 1,990 end-stage renal disease patients in 30 centers were treated with continuous ambulatory peritoneal dialysis by the Italian Cooperative Peritoneal Dialysis Study Group. At the start of treatment, patients had an average age of 58.4 years, with a 66% prevalence of one or more clinical risk factors for premature death. Patient survival was 51% and 33% at 4 and 8 years on continuous ambulatory peritoneal dialysis, respectively, and technique survival was 62% and 48%, respectively. Occurrences of peritonitis progressively reduced until they reached an incidence of 0.50 episodes/yr in the last 5 years (1985 to 1989). Hernias and catheter-related problems did not influence the dropout rates. These Italian Cooperative Peritoneal Dialysis Study Group results demonstrate that continuous ambulatory peritoneal dialysis is a viable dialysis technique for long-term treatment of chronic renal failure and that it is an effective alternative to hemodialysis, especially for older and high-risk patients.

Well being in patients on CAPD and hemodialysis.

In the present multicenter study, 120 pts who had been treated by both hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) for at least 6 months each, were invited to answer questions on 34 matters, to compare symptoms and their well-being while on the two treatments. Patients were invited to choose HD or CAPD and indicate the reasons for their choice. For 28 patients the first treatment was HD and for 92 CAPD. The mean time between the change of therapy and the study was 46 +/- 35 months. Their final choices were found to be strictly related to the present treatment (p < 0.001). The reasons for choice of CAPD were: more free time (21%), more freedom (67%), better well-being (44%), less worry (5%); for HD they were: more free time (53%), better well-being (39%), less worry (13%), no need for a peritoneal catheter and fewer clinical complications (19%). The catheter was considered more cumbersome than the A.V. fistula, the time involved was considered to be shorter on HD by 52 patients and on CAPD by 39, thirst and cramps were considered to be more frequent and severe on CAPD by half of the patients. The prevalence and severity of problems and symptoms and choice of treatment were not related to sex, job, education or age.

[Changes in dialysis methods. 10 years' experience]. / Cambi di metodica dialitica. Esperienza di 10 anni.

A retrospective survey has been done on 175 chronic patients who underwent dialysis in one center, between January 1982 and June 1992. The purpose of the work was to evaluate the use of the first treatment and the cause which determined a change of treatment. Diffusive haemodialysis and CAPD were the most frequent first choice techniques, respectively in extracorporeal and peritoneal dialysis, whereas changes were conditioned by the need for a more personalized treatment, especially in the filed of extracorporeal dialysis.