Changes of peritoneal transport parameters with time on dialysis: assessment with sequential peritoneal equilibration test.

BACKGROUND: Sequential peritoneal equilibration test (sPET) is based on the consecutive performance of the peritoneal equilibration test (PET, 4-hour, glucose 2.27%) and the mini-PET (1-hour, glucose 3.86%), and the estimation of peritoneal transport parameters with the 2-pore model. It enables the assessment of the functional transport barrier for fluid and small solutes. The objective of this study was to check whether the estimated model parameters can serve as better and earlier indicators of the changes in the peritoneal transport characteristics than directly measured transport indices that depend on several transport processes. METHODS: 17 patients were examined using sPET twice with the interval of about 8 months (230 ± 60 days). RESULTS: There was no difference between the observational parameters measured in the 2 examinations. The indices for solute transport, but not net UF, were well correlated between the examinations. Among the estimated parameters, a significant decrease between the 2 examinations was found only for hydraulic permeability LpS, and osmotic conductance for glucose, whereas the other parameters remained unchanged. These fluid transport parameters did not correlate with D/P for creatinine, although the decrease in LpS values between the examinations was observed mostly for patients with low D/P for creatinine. CONCLUSIONS: We conclude that changes in fluid transport parameters, hydraulic permeability and osmotic conductance for glucose, as assessed by the pore model, may precede the changes in small solute transport. The systematic assessment of fluid transport status needs specific clinical and mathematical tools beside the standard PET tests.

Peritoneal Fluid Transport rather than Peritoneal Solute Transport Associates with Dialysis Vintage and Age of Peritoneal Dialysis Patients.

During peritoneal dialysis (PD), the peritoneal membrane undergoes ageing processes that affect its function. Here we analyzed associations of patient age and dialysis vintage with parameters of peritoneal transport of fluid and solutes, directly measured and estimated based on the pore model, for individual patients. Thirty-three patients (15 females; age 60 (21-87) years; median time on PD 19 (3-100) months) underwent sequential peritoneal equilibration test. Dialysis vintage and patient age did not correlate. Estimation of parameters of the two-pore model of peritoneal transport was performed. The estimated fluid transport parameters, including hydraulic permeability (LpS), fraction of ultrasmall pores (α u), osmotic conductance for glucose (OCG), and peritoneal absorption, were generally independent of solute transport parameters (diffusive mass transport parameters). Fluid transport parameters correlated whereas transport parameters for small solutes and proteins did not correlate with dialysis vintage and patient age. Although LpS and OCG were lower for older patients and those with long dialysis vintage, αu was higher. Thus, fluid transport parameters--rather than solute transport parameters--are linked to dialysis vintage and patient age and should therefore be included when monitoring processes linked to ageing of the peritoneal membrane.

Sequential peritoneal equilibration test: a new method for assessment and modelling of peritoneal transport.

BACKGROUND: In spite of many peritoneal tests proposed, there is still a need for a simple and reliable new approach for deriving detailed information about peritoneal membrane characteristics, especially those related to fluid transport. METHODS: The sequential peritoneal equilibration test (sPET) that includes PET (glucose 2.27%, 4 h) followed by miniPET (glucose 3.86%, 1 h) was performed in 27 stable continuous ambulatory peritoneal dialysis patients. Ultrafiltration volumes, glucose absorption, ratio of concentration in dialysis fluid to concentration in plasma (D/P), sodium dip (Dip D/P Sodium), free water fraction (FWF60) and the ultrafiltration passing through small pores at 60 min (UFSP60), were calculated using clinical data. Peritoneal transport parameters were estimated using the three-pore model (3p model) and clinical data. Osmotic conductance for glucose was calculated from the parameters of the model. RESULTS: D/P creatinine correlated with diffusive mass transport parameters for all considered solutes, but not with fluid transport characteristics. Hydraulic permeability (L(p)S) correlated with net ultrafiltration from miniPET, UFSP60, FWF60 and sodium dip. The fraction of ultrasmall pores correlated with FWF60 and sodium dip. CONCLUSIONS: The sequential PET described and interpreted mechanisms of ultrafiltration and solute transport. Fluid transport parameters from the 3p model were independent of the PET D/P creatinine, but correlated with fluid transport characteristics from PET and miniPET.

Extracorporeal versus peritoneal ultrafiltration in diuretic-resistant congestive heart failure--a review.

Diuretic-resistant congestive heart failure in the form of type 2 cardiorenal syndrome is a problem of growing significance in everyday clinical practice because of high morbidity and mortality. There has been scant progress in the treatment of overhydration, the main cause of symptoms in this group of patients. The aim of our review is to present recent advances in the ultrafiltration therapy of congestive heart failure, with special attention to the new dedicated device for extracorporeal isolated ultrafiltration, as well as modifications of peritoneal dialysis in the form of peritoneal ultrafiltration with icodextrin solution and incremental peritoneal dialysis. Technical and clinical features, costs and potential risks of available devices for isolated ultrafiltration are presented. This method should be reserved for patients with true diuretic resistance as part of a more complex strategy aiming at the adequate control of fluid retention. Peritoneal ultrafiltration is presented as a viable alternative to extracorporeal ultrafiltration because of medical and psychosocial benefits of home-based therapy, lower costs and more effective daily ultrafiltration. In conclusion, large, properly randomized and controlled clinical trials with long-term follow-up will be essential in assessing the logistics and cost-effectiveness of both methods. Most importantly, however, they should be able to evaluate the impact of both methods on preservation of renal function and delaying the progression of heart failure by interrupting the vicious circle of cardiorenal syndrome. Our review is supplemented with the case report of the use of peritoneal ultrafiltration with a single 12-hour nighttime icodextrin exchange as a life-saving procedure in a patient with congestive heart failure resistant to pharmacological treatment.

Peritoneal dialysis as a therapeutic approach in congestive heart failure resistant to pharmacological treatment.

Given an increasing number of patients with congestive heart failure (CHF) refractory to diuretics, new and more effective therapeutic modalities are sought. Peritoneal dialysis (PD), which provides continuous, slow ultrafiltration, may be an alternative to hemodialysis in this population. The current paper, based on a comprehensive literature review, addresses the role of PD in improving the quality of life of patients with CHF.

Peritoneal dialysis as a therapeutic approach in congestive heart failure resistant to pharmacological treatment: case report.

This report describes the use of continuous peritoneal dialysis (PD) as an alternative to hemodialysis (HD) in a patient with type 2 cardiorenal syndrome in the course of congestive heart failure resistant to standard pharmacological treatment. A 39-year-old man presented with a 24-year history of progressive heart failure. Ineligibility for heart transplant and previous inefficient treatment with different modifications of HD reduced his treatment options to PD. After 7 months of continuous PD (1 overnight exchange with icodextrin and 2 daily standard continuous ambulatory PD exchanges) his overall condition significantly improved compared with his status while on HD. An increase from NYHA class IV to class II, increase in left ventricular ejection fraction from 50% to 55%, decrease in right ventricular systolic pressure from 73 to 53 mmHg, and improvement in the quality of life enabled him to resume his daily activities.

[Cinacalcet in the therapy of secondary hyperparathyroidism--own experiences]. / Doswiadczenia wlasne w stosowaniu cynakalcetu u chorych z wtónq nadczynnoscia przytarczyc.

UNLABELLED: Secondary hyperparathyroidism (sHPT) affects 20-25% dialysed patients and is related to the bone, mineral and cardiovascular complications. Cinacalcet, acts on the calcium-sensing receptor increasing its sensitivity to calcium, thereby reducing parathyroid hormone (PTH) secretion. The aim of this study was to evaluate the effect of cinacalcet in dialysed patients with sHPT Material and methods. We studied group of 12 patients on dialysis > 3 month with sHPT and baseline iPTH > 450 pg/ml (F = 6, M = 6; peritoneal dialysis 2 patients and HD 10 patients; mean age 56 +/- 14). Cinacalcet was titrated from 30 mg once daily during a 6 month period. The following parameters were determined in serum: iPTH, Ca, P, before onset of therapy and every 4 weeks during 6 months therapy. RESULTS: Serum iPTH significantly decreased after 4 weeks therapy compared to the start point (from 849 +/- 253 to 338 +/- 260 pg/ml) and after 24 weeks cinacalcet therapy to 298 +/- 153 pg/ml. (64% reduction). Serum calcium and phosphate decrease but not significantly 8.7 +/- 1.2 vs 8.6 +/- 1.1 mg/dl and 7.3 +/- 2.8 vs 6.3 +/- 1.7 mg/dl respectively. There weren't serious adverse events. CONCLUSIONS: Cinacalcet is effective and well tolerated nonsurgical management treatment of secondary hyperparathyroidism in dialysed patients.

[Ambulatory or home peritoneal dialysis--time for changes?]. / Ambulatoryjna czy domowa dializa otrzewnowa--czas na zmiany?

Ambulatory peritoneal dialysis need to be adopted to the changing population of patients with irreversible renal failure who require more and more nursing support in normal performance of dialysis procedure. Such possibility might be provided by introduction of supported or assisted by medical personal peritoneal dialysis in patient's home.

[Transperitoneal transport of water and substances--between theory and practice]. / Transport przezotrzewnowy wody i substancji--miedzy teoria a praktyka.

The practical use of the own method of prediction of peritoneal dialysis adequacy, based on direct assessment of transperitoneal transport, has been presented in this study.

[Extended assessment of peritoneal transport kinetics of substances and water as an important element of integrated dialysis care]. / Rozszerzona ocena kinetyki transportu przezotrzewnowego czqsteczek i wody jako wazny element koncepcji zintegrowanej opieki dializacyjnej.

UNLABELLED: The concept of integrated dialysis care is based on the choice of the most optimal method of renal replacement therapy for particular patient in particular period of disease. In many cases peritoneal dialysis (PD) is the initial therapy. PD modalities and regimens are modified according to values of parameters of ultrafiltration and adequacy. The routinely used methods of analysis of peritoneal transport are very useful for general assessment of properties of peritoneum as a dialysis membrane. However, the application of these methods do not guarantee the full assessment of peritoneal transport kinetics of water and substances. Therefore, the capabilities of the most adequate modification are limited. The tests based on mathematical models taking into account the kinetics of intraperitoneal dialysate volume seem to be the right supplement of standard methods. MATERIALS AND METHODS: To illustrate the problem mentioned above, the aim of this study was comparison of peritoneal transport of substances and water in two groups of patients: group I with negative ultrafiltration (UF) (n=14) and group II with positive UF (n=6). In the studied groups peritoneal equilibration test (PET) was done, then the assessment of peritoneal water transport was performed using 125I-HSA as dialysate volume marker, and finally the velocity of peritoneal transport of small molecules expressed by solute mass transport rate (SMTR) coefficient was measured. Patients from both groups belonged to the same category of high-average transporters according to PET criteria. RESULTS: On the base of broaden assessment of peritoneal transport of water and substances it was proved that different, "therapeutic approach" should be applied in studied groups to reach the adequate dialysis. Although in group II the minor modification of continuous ambulatory peritoneal dialysis (CAPD) regimen was desired, the radical change of CAPD schedule or transfer to automated peritoneal dialysis was necessary in cases of patients from group I. CONCLUSIONS: The results of the study indicate that the extended assessment of peritoneal transport kinetics of water and substances increases the capabilities of individualisation of PD program. Therefore, it should be treated as an important element of integrated dialysis care.

[Encapsulating peritoneal sclerosis as a serious complication of peritoneal dialysotherapy--current opinions on treatment and prevention]. / Encapsulating peritoneal sclerosis jako powazne powiklanie dializoterapii otrzewnowej--wspólczesne poglady na leczenie i zapobieganie.

Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of peritoneal dialysis program. It is characterised by high mortality. This article is a review of current knowledge concerning procedures in EPS. The views on change of renal replacement therapy--from peritoneal dialysis to hemodialysis were discussed. The possibilities of prevention and treatment of this complication were also presented.

Efficacy of automated peritoneal dialysis: from minimum to optimum.

The aim of the study was assessment of theoretical possibilities of the Automated Peritoneal Dialysis (APD) optimization. The analysis of influence of dwells number modification and peritoneal transport character on Nightly Intermittent Peritoneal Dialysis (NIPD) efficacy and adequacy was performed. In the study the alternative method of theoretical foreseeing of peritoneal dialysis efficacy and adequacy was applied. This method was based on direct measurement of the velocity of solute peritoneal transport (SMTR). On the basis of SMTR, the dialysis efficacy expressed as total dialysed urea and dialysis adequacy expressed as Kt/V were estimated. The values of listed parameters were calculated for the different NIPD schedules (4-9 dwells during 8-hours session). It was revealed that the shortening of dwell time with simultaneous multiplying of dwell numbers resulted in increase of dialysis efficacy and adequacy. However, this improvement was non-proportional to the increase of dialysis solution volume and it did not provide the optimum of dialysis nor recommended level of adequacy even during the session consisting of 9 dwells. There were no statistically significant differences of Kt/V values between subgroups of patients with different character of peritoneal transport assessed according to PET test. The tendency to achieve the recommended values of Kt/V was observed in high transporters group. The results of the study indicate the large capabilities of APD optimization. The direct measurement of peritoneal transport velocity allows to provide better individualization of PD program. The prediction of APD efficacy and adequacy on the base of presented method seams to be an interesting alternative.

[Mathematical analysis of the possibilities of automated peritoneal dialysis optimization]. / Matematyczna analiza mozliwosci optymalizacji automatycznej dializy otrzewnowej.

The aim of the study was assessment of theoretical possibilities of the Automated Peritoneal Dialysis (APD) optimization. The analysis of influence of dwells number modification and peritoneal transport character on Nightly Intermittent Peritoneal Dialysis (NIPD) efficacy and adequacy was performed. 20 patients were included in the study. The velocity of urea peritoneal transport expressed as SMTR (solute mass transport rate) was calculated according to the formula: SMTR = delta (CDVD)/delta t, where: delta (CDVD)--change of urea mass in dialysate during delta t time (CD-urea concentration in dialysate, VD-intraperitoneal volume of dialysate). VD was estimated from dilution of volume marker (RISA). On the basis of SMTR, the dialysis efficacy expressed as total dialysed urea and dialysis adequacy expressed as Kt/V were estimated. The values of listed parameters were calculated for the different NIPD schedules (4-9 dwells during 8-hours session). It was revealed that the shortening of dwell time with simultaneous multiplying of dwell numbers resulted in increase of dialysis efficacy and adequacy. However, this improvement was non-proportional to the increase of dialysis solution volume and it did not provide the optimum of dialysis nor recommended level of adequacy even during the session consisting of 9 dwells. There were no significant differences of Kt/V values between subgroups of patients with different character of peritoneal transport assessed according to PET test. The tendency to achieve the recommended values of Kt/V was observed in high transporters group. The results of the study indicate the large capabilities of APD optimization. The direct measurement of peritoneal transport velocity allows to provide better individualization of PD program. The prediction of APD efficacy and adequacy on the base of presented method seams to be an interesting alternative.

[Empirical therapy of peritonitis in peritoneal dialysis patients--it is reasonable to use a new therapeutic schedule?]. / Empiryczne leczenie dializacyjnego zapalenia otrzewnej--czy uzasadnione jest stosowanie nowego schematu terapeutycznego?

The Ad Hoc Advisory Committee on Peritonitis Management recommended in the year 2000 a new protocol of empirical peritonitis therapy in patients on peritoneal dialysis with preserved residual renal function (RRF). This protocol comprises 1st and 3rd generation cephalosporins. According to these recommendations the old protocol of therapy, comprising 1st generation cephalosporin and aminoglycoside may be used only in patients with diuresis lower than 100 ml/day. The aim of the study was a retrospective assessment of the efficacy and cost of peritonitis therapy using "old" and "new" protocols. The analysed episodes of peritonitis were divided into two groups. Group 1 included 22 episodes of peritonitis in 13 patients treated with the old protocol, in whom RRF was lower than 100 ml/day. Group 2 included 6 episodes of peritonitis in 4 patients with preserved RRF treated with the new protocol. The efficacy of the treatment according to the old protocol was 64% and according to the new protocol--33%. The average cost of 14-day therapy with the old and new schedule was 67.1 and 247.2 Euro, respectively. In our studied population a considerably lower efficacy and higher cost were revealed of the new empirical schedule of peritonitis treatment in comparison to the old schedule. The results of the study indicate the need of further estimation of the usefulness of the new peritonitis empirical treatment protocol.