The truth on current peritoneal dialysis: state of the art.

The share of peritoneal dialysis (PD) in the spectrum of chronic dialysis has decreased markedly in the Netherlands in the last 15 years. Consequently, the knowledge of nephrologists and nursing staff on PD has declined leading to a negative spiral in which loss of experience resulted in loss of enthusiasm to offer PD to patients and also in less interest in the new PD developments. All these changes took place while the results of PD improved and patient survival was at least similar to that on haemodialysis. The aim of this review is first to give a summary of the principles and practice of patient and staff education and to describe the role of the medical contribution in decision-making. On this basis, the second aim is to update internist-nephrologists on a number of issues that have been underexposed in the past. Recent patient and technique survival data of PD patients is reviewed, and also the new insights into dialysis adequacy. The presence of residual renal function is the main determinant of patient survival together with prevention of overhydration. Urea and creatinine removal are not important at all when patients are still passing urine. Many early problems with PD are due to the peritoneal catheter and suggestions are made for improvement of its function. The prevention and management of infections is reviewed, and also the regular assessment of peritoneal function. Free water transport is a predictor of encapsulating peritoneal sclerosis (EPS), which should be assessed regularly. The pathogenesis of EPS, treatment and the decreasing incidence are discussed.

Peritoneal dialysis underscores its merits in portal hypertensionrelated and nephrogenic ascites.

In the Western world, peritoneal dialysis (PD) is less frequently applied as substitute therapy in end-stage renal disease (ESRD). In the Netherlands the use of PD has decreased from 30.3 to 13.5% due to several factors, but not due to lower PD-related outcome. The lower penetrance of PD diminishes experience with and exposure of young professionals to this treatment modality. This does not enhance a free and motivated choice among renal replacement therapies for patients who cannot be transplanted pre-emptively. To rejuvenate interest in PD and to underscore its merits, we would like to share the use of PD on two extraordinary occasions, where PD was the only way out. Ascites due to portal hypertension with profound gastrointestinal haemorrhage and nephrogenic ascites poses major management challenges in ESRD patients. In conclusion, PD came to the rescue and tremendously increased quality of life in the patients presented. To be readily available, a certain penetrance of and expertise in PD as renal replacement therapy is warranted.

Patients' representations of their end-stage renal disease: relation with mortality.

BACKGROUND: Self-regulation theory explains how patients' illness perceptions influence self-management behaviour (e.g. via adherence to treatment). Following these assumptions, we explored whether illness perceptions of ESRD-patients are related to mortality rates. METHODS: Illness perceptions of 182 patients participating in the NECOSAD-2 study in the period between December 2004 and June 2005 were assessed. Cox proportional hazard models were used to estimate whether subsequent all-cause mortality could be attributed to illness perception dimensions. RESULTS: One-third of the participants had died at the end of the follow-up. Mortality rates were higher among patients who believed that their treatment was less effective in controlling their disease (perceived treatment control; RR = 0.71, P = 0.028). This effect remained stable after adjusting for sociodemographic and clinical variables (RR = 0.65, P = 0.015). CONCLUSIONS: If we consider risk factors for mortality, we tend to rely on clinical parameters rather than on patients' representations of their illness. Nevertheless, results from the current exploration may suggest that addressing patients' personal beliefs regarding the effectiveness of treatment can provide a powerful tool for predicting and perhaps even enhancing survival.

Hemodialysis (HD) versus peritoneal dialysis (PD): latent overhydration in PD patients?

Data on the difference in fluid status between hemodialysis (HD) and peritoneal dialysis (PD) patients are scarce. Bio-electrical impedance analysis (BIA) is able to detect total body water (TBW) and its distribution in intracellular (ICW) and extracellular water (ECW). Echographic determination of the diameter of the inferior caval vein (VCD) provides information about the intravascular space (IVS). Nineteen PD-patients and 20 HD-patients in stable clinical condition were studied. In HD-patients a significant decrease in VCD, mean arterial pressure (MAP), TBW and ECW was noted due to ultrafiltration. Both ratios of VCD to ICW/ECW and of VCD to ECW/TBW decreased. No significant differences were found in these variables between PD-patients and HD-patients before HD. In both patient groups the measured variables pointed towards overhydration and the increased ratios both of VCD to ICW/ECW and VCD to ECW/TBW towards the storage of surplus of fluid in the intravascular space. It can be concluded that both PD-patients and HD-patients before HD have a surplus of fluid in the extracellular compartment, predominantly stored in the intravascular space.

Intraperitoneal ciprofloxacin and rifampicin versus cephradine as initial treatment of (C)APD-related peritonitis: a prospective randomized multicenter comparison (CIPPER trial).

OBJECTIVE: The initial treatment of peritonitis has evolved from single-agent to combination regimens. The initial response rates improved with these newer regimens but relapsing peritonitis continues to occur. For biofilm-embedded or intracellularly sequestrated bacteria, a combination of intracellularly- and biofilm-active agents such as ciprofloxacin and rifampicin might be beneficial. Many Dutch centers continue to use cephradine as initial treatment, claiming clinically adequate responses with this regimen. We compared the impact of these two regimens on outcome in patients who developed a new episode of peritonitis. DESIGN: Prospective randomized open trial. SETTING: Multicenter study including 14 Dutch dialysis units. PATIENTS AND INTERVENTIONS: From October 1996 to October 1999, 367 patients from 14 centers were randomized to be treated with ciprofloxacin + rifampicin (CR; each 50 mg/L) or cephradine (C; 250 mg/L) in case of peritonitis. Of these 367 patients, 98 developed peritonitis, 44 of whom were treated with CR and 54 with C. MAIN OUTCOME MEASURES: Clinical response, divided into early (during the 2 weeks of therapy) and late (including the following 4 weeks) response. Success was defined as disappearance of all signs and symptoms by days 4-6, through day 42. Bacteriological response was either success (eradication) or failure (persistence, superinfection, or eradication with relapse/reinfection). RESULTS: The groups were comparable for age, sex, duration of continuous ambulatory/automated peritoneal dialysis, and occurrence of diabetes. Bacteriological cultures in both groups revealed predominantly gram-positive micro-organisms. Initial and late clinical successes were obtained in 27/54 and 20/54 episodes (50% and 37%) in the C group, and 33/44 and 28/44 episodes (75% and 63.6%) in the CR group (p = 0.021 and p = 0.019). Bacteriological success occurred in 29.6% in the C group, and in 59.1% in the CR group (p= 0.026), with failure in 46.3% and 18.2%, respectively. Peritonitis episodes were bacteriologically not evaluable in 24.1% of episodes in the C group and 22.7% of episodes in the CR group, due mostly to no growth in the initial culture. CONCLUSION: The CIPPER Trial showed ciprofloxacin + rifampicin to be superior to cephradine as empiric treatment of peritonitis.

Diameter of inferior caval vein and impedance analysis for assessment of hydration status in peritoneal dialysis.

In 19 stable peritoneal dialysis (PD) patients, hydration status was evaluated by measurement of vena cava diameter (VCD) and bioelectrical impedance analysis (BIA) variables: intracellular water (ICW), extracellular water (ECW), and total body water (TBW). We investigated whether BIA can replace VCD. VCD did not correlate with TBW but correlated moderately with ECW/TBW (r = 0.42; 0.025 < p < 0.05) and ICW/ECW (r = -0.47; p < 0.025). Patients with underhydration (n = 4; VCD <8 mm/m2) revealed limits for BIA variables as ICW/ECW (>1.50) and ECW/TBW (<0.40). The same held true for overhydration (n = 5; VCD >11.5 mm/m2): ICW/ECW (<1.50) and ECW/TBW (>0.40). Although the positive predictive value of ICW/ECW and ECW/TBW for both under- and overhydration was only 50% and 54%, respectively, there were no false negative values. Although BIA cannot replace VCD in PD patients, the reverse holds true as well. Combining BIA and VCD may lead to a better estimation of hydration status because both techniques provide complementary information.

The impact of equations on calculation of lean body mass by bioelectrical impedance analysis in RDT patients.

Several equations are available to derive lean body mass (LBM) from bioelectrical impedance analysis (BIA). The purpose of this study was to investigate in dialysis patients the impact of the equation used on the outcome of LBM assessment. To avoid dyshydration as a confounder, vena cava diameter measurement was used to assess normohydration in the 21 patients studied. Five equations were compared. In a previously published study to assess total body water using antipyrine as a gold standard, Deurenberg's formula was advocated to be used in the estimation of LBM by BIA. Therefore, this formula was used as a basis for comparison with the other four equations. One equation gave results comparable to those obtained by Deurenberg's formula. Despite high correlations and agreement according to Bland and Altman analysis, the other three equations showed a significant difference with Deurenberg-derived LBM. Thus, the equation used has a major impact on the outcome of LBM estimations.

[Stress ulcer prophylaxis in the intensive care unit]. / Stressulcusprofylaxe op de intensive-careafdeling.

In the early years of intensive care a stress ulcer related bleeding, occurring in 20-30% of the IC population, became recognized as a significant cause of morbidity and mortality. Due to improved intensive care medicine (including adequate early resuscitation, analgesia, sedation) the incidence of stress ulcer-related bleeding in the IC has decreased markedly. Without pharmacological prophylaxis incidences ranging from 0.6 to 6% were reported. It is not recommended to apply stress ulcer prophylaxis on a routine basis, it should be reserved for patients with an increased risk of a stress ulcer-related bleeding. In patients with neurotrauma, severe burn, recent peptic ulcer or bleeding and those with coagulopathy prophylaxis with ranitidine is advised.

Diameter of inferior caval vein (VCD) and bioelectrical impedance analysis (BIA) for the analysis of hydration status in patients on hemodialysis.

BACKGROUND: Vena cava diameter (VCD) measurement is an accepted method to evaluate hydration status in patients on hemodialysis. Bioelectrical impedance analysis (BIA) is a less laborious method to assess hydration variables and more suitable for routine patient care. However, BIA has not yet been validated in dialysis patients. We investigated whether BIA can replace VCD in patients on hemodialysis. METHODS: In 20 stable hemodialysis patients [age (+/-SD): 47+/-17 yrs, dialysis duration (+/-SD): 76+/-59 months] hydration status was evaluated by VCD. Impedance variables such as resistance, reactance and phase angle were provided by BIA. They were used to calculate intracellular water (ICW), extracellular water (ECW) and total body water (TBW). RESULTS: VCD did not correlate with TBW-BIA, but correlated with ECW/TBW (r = 0.46; p<0.025), ECW/m2 (r = 0.42; p<0.005) and ICW/ECW (r = -0.49; p<0.005). Hemodialysis decreased TBW with 2.7+/-1.91. The difference in ECW before and after dialysis (8.9+/-1.3 and 7.4+/-1.41, respectively) was significant (p = 0.001). The same did not hold true for ICW (13.3+/-1.4 and 13.1+/-1.41). Major underhydration (n = 9; VCD <6.5 mm/m2) revealed sharp limits for ICW/ECW (>1.80) and ECW/TBW (<0.35), whereas these BIA-variables were significantly (p<0.005) different from those in minor underhydration (n = 8; 6.6 < VCD <8.0 mm/m2), normohydration (n = 15; 8 11.5 mm/m2). CONCLUSION: BIA can replace VCD only in major underhydration (VCD < 6.5 mm/m2). Fluid loss during hemodialysis is caused by a decrease of ECW, compatible with the postulation that excess fluid volume is carried by the extracellular compartment.

Four-site skinfold anthropometry (FSA) versus body impedance analysis (BIA) in assessing nutritional status of patients on maintenance hemodialysis: which method is to be preferred in routine patient care?

BACKGROUND: Both four-site skinfold anthropometry (FSA) and bioelectrical impedance analysis (BIA) claim to be useful in routine clinical practice of maintenance dialysis as easy methods to assess nutritional status. The purpose of this study was to investigate which of these two methods is to be preferred. METHODS: Both before and after dialysis nutritional and hydration status were evaluated by BIA in 20 stable hemodialysis patients. Variables of nutritional status as lean body mass (LBM) and body fat (BF) were assessed by four-site skinfold anthropometry (LBM-FSA and BF-FSA) and BIA (LBM-BIA and BF-BIA). Variables of hydration status were total body water (TBW), its distribution into intracellular and extracellular compartments (ICW and ECW, respectively) and ICW/ECW. RESULTS: Weight loss during dialysis correlated with a change of LBM-FSA (r = 0.75, p <0.005) and also with that of LBM-BIA (r = 0.69, p < 0.005). To promote reliability of follow-up measurements in intervention studies it is warranted to evaluate nutritional status in an unchanged hydration status. The highly significant correlation (r = 0.93, p < 0.005) between the two techniques and the comparability between means and SD indicate that both techniques were almost equivalent to each other, although, compared to LBM-BIA, LBM-FSA was less affected by changes in fluid status. The sam held true for BF-BIA and BF-FSA. BF-FSA correlated significantly with BF-BIA (r = 0.65, p <0.005), whereas no difference of mean +/- SD was found between BF-FSA and BF-BIA. CONCLUSION: FSA and BIA are almost comparable techniques to assess both LBM and BF, although FSA is less affected by changes in fluid status. However, assessing LBM in normohydration is mandatory. Compared with FSA, BIA is able to establish hydration status and lacks depency on operator interpretation. Therefore, in routine patient care the BIA technique is the one to be preferred.

Detection of hydration status by total body bioelectrical impedance analysis (BIA) in patients on hemodialysis.

The purpose of the present study was to investigate whether total body bioelectrical impedance analysis (BIA) could be appropriate to assess normohydration (i.e. dry weight) in hemodialysis patients. This study is warranted, because the simultaneous assessment of both hydration and nutritional status by BIA requires the presence of a situation of normohydration in order to guarantee valid conclusions about the nutritional analysis. Segmental bioelectrical impedance was performed to classify patients according to their hydration status. BIA measurements revealed significant differences in TBW, ECW and ICW/ECW between three hydration subgroups (under-, normo-, and overhydration), whereas ICW was similar. Therefore, TBW, ECW and ICW/ECW appear appropriate variables to assess hydration status in patients on hemodialysis. Hemodialysis diminished ECW significantly, whereas ICW did not change, suggesting that a decrease of ECW explains the fluid loss during hemodialysis.

Assessment of total body water and lean body mass from anthropometry, Watson formula, creatinine kinetics, and body electrical impedance compared with antipyrine kinetics in peritoneal dialysis patients.

BACKGROUND: Indirect methods such as anthropometry (A), Watson formula (W), creatinine kinetics (CK), and body electrical impedance (BEI) are increasingly applied to determine total body water (TBW) and lean body mass (LBM) in dialysis patients. These methods share the disadvantage that they have been validated for healthy men only. We studied which of these four commonly applied methods can best be used routinely in CAPD patients. METHODS: TBW estimates obtained from A, W, CK, and BEI were compared with those obtained by a gold standard (antypirine distribution volume, ADV) in eight CAPD patients. In addition, several BEI equations to derive lean body mass (LBM) were compared with LBM estimated by ADV in order to determine which equation is the most valuable for the assessment of LBM by BEI in CAPD patients. RESULTS: TBW as ADV was 41.4 +/- 6.6 (mean +/- SD) L. TBW estimated by W, A and CK underestimated ADV by a mean +/- SD of 2.3 +/- 13, 5 +/- 8.4 and 12.3 +/- 10.9% respectively. TBW as measured by BEI overestimated ADV by 2.5 +/- 8.8%. The correlation coefficients between ADV-TBW and TBW estimated by the indirect methods were r = 0.88 (A), r = 0.87 (BEI), r = 0.82 (CK), and 0.68 (W). LBM estimated by ADV was 56.7 +/- 8.9 (mean +/- SD) kg; LBM by different BEI equations ranged from 49.9 +/- 7 to 58.1 +/- 10.7 kg. The correlation coefficient between LBM by ADV and LBM according to the various BEI equations ranged from 0.81 to 0.93. CONCLUSION: A and BEI can be used to estimate TBW, but the considerable SD (or inaccuracy) makes individual predictions hazardous. Considering the correlation coefficients and difference between LBM by ADV and LBM according to different BEI equations, Deurenberg's formula can be advocated for use in the estimation of LBM by BEI.

Acute cardiorespiratory failure as presenting symptom of chronic lymphocytic leukemia.

A patient with acute cardiorespiratory failure caused by hyperleukocytosis due to chronic lymphocytic leukaemia (CLL) is described. Although acute pulmonary failure due to leukostasis is a known and often postmortem finding in patients with acute myelocytic leukaemia (AML) or chronic myelocytic leukaemia (CML) in blastic crises, it is rare in CLL.

Low-calcium peritoneal dialysis fluid should not impact peritonitis rates in continuous ambulatory peritoneal dialysis.

It has been suggested that reducing the calcium content of peritoneal dialysis fluid (PDF) to 2.5 mEq/L decreases peritoneal macrophage (PMO) function and increases the incidence of peritonitis (especially Staphylococcus epidermidis peritonitis) in continuous ambulatory peritoneal dialysis patients. We studied the uptake and killing of S epidermidis and Escherichia coli by PMOs and peripheral blood leukocytes incubated in control buffer (Hank's balanced salt solution containing 0.1% gelatin [GHBSS]) and PDF containing varying concentrations of calcium (O to 3.5 mEq/L) and magnesium (O to 1.5 mEq/L) using ether diamine tetraacetic acid and ethylenediaminetetraacetic acid chelation, respectively. In addition, interleukin-1-beta-induced interleukin-6 production by human mesothelial cells was measured in the presence of concentrations of calcium increasing from 0 to 3.0 mmol/L. Fc receptor- mediated uptake of S epidermidis by PMO in the complete absence of Ca++ was comparable to that by PMO incubated in GHBSS with calcium. In contrast, the complement-dependent uptake of E coli was significantly lower in GHBSS devoid of Ca++ (46% +/- 5% v 24% +/- 3%; 0.05 < P < 0.02). No effect on intracellular killing of either microorganism by PMO was observed. The same held true for the phagocytic and killing capacity of polymorphonuclear granulocytes and monocytes obtained from healthy donors. Using Ca++ (2 to 3.5 mEq/L) and Mg++ (0.5 to 1.5 mEq/L) concentrations as applied in commercial PDFs, however, phagocytes performed as well as in control buffer. Interleukin-6 production by stimulated human mesothelial cells also required a small amount of Ca++ only, being normal above the 0.1 to 3 mmol/L Ca+ + range tested. Thus, complement- dependent uptake of bacteria by phagocytes is calcium dependent, whereas antibody-dependent uptake of S epidermidis is not. The concentrations of calcium in the current PDFs, however, will not compromise human mesothelial cells and leukocyte functions, and therefore should not impact the peritonitis rate.

Does additional treatment with fish oil mitigate the side effects of recombinant human erythropoietin in dialysis patients?

Since fish oil has been reported to reduce platelet aggregability, to reduce blood viscosity by increasing red blood cell deformability and to lower blood pressure, we studied the effect of dietary supplementation with fish oil on the occurrence of adverse effects in patients receiving recombinant human erythropoietin (rHuEPO). In a prospective, randomized, double blind cross-over design we studied the effect of daily ingestion of 3 g fish oil versus 3 g corn oil (placebo) for 5 months, with a wash-out period of 3 months in between. Thirty-two dialysis patients newly treated with rHuEPO participated. rHuEP0 was given using a low and slow dose regimen (25 U/kg twice weekly s.c.). Target Hct was 35%. Blood pressure, red blood cell deformability, plasma viscosity, fatty acid composition of plasma phospholipids, and fibrinogen levels were measured at 0, 5, 8 and 13 months. In both groups a stable target Hct (35%) was reached within 3 months. Blood pressure was not significantly different between the groups at any time point. In 4 patients (2 on fish oil and 2 on placebo) antihypertensives had to be increased to regulate blood pressure adequately, whereas shunt occlusion occurred in one patient on placebo. Despite a significant increase in the omega-3 fatty acid content of plasma phospholipids during ingestion of fish oil, no significant changes in red blood cell deformability were observed. Since hypertension and shunt occlusion occurred at rates comparable to those reported in the literature, long-term ingestion of fish oil does not appear to mitigate the side effects of low and slow dose rHuEPO.

Clinical efficacy and morbidity associated with continuous cyclic compared with continuous ambulatory peritoneal dialysis.

OBJECTIVE: To assess the clinical efficacy and morbidity of continuous cyclic peritoneal dialysis compared with continuous ambulatory peritoneal dialysis with a Y-connector as renal replacement therapy. DESIGN: Prospective, randomized study. SETTING: University hospital. PATIENTS: All new patients with end-stage renal failure consecutively entering the dialysis program from January 1988 through July 1991 were randomly assigned to receive continuous ambulatory peritoneal dialysis with a Y-connector or continuous cyclic peritoneal dialysis and were followed prospectively. MEASUREMENTS: Patient and technique survival, dialysis adequacy, and (infectious) morbidity. RESULTS: Forty-one patients (median age, 56 years; range, 18 to 86 years) started continuous ambulatory peritoneal dialysis with a Y-connector (follow-up, 688 patient-months), and 41 patients (median age, 54 years; range 21 to 76 years) started continuous cyclic peritoneal dialysis (follow-up, 723 patient-months). The two groups showed no significant differences in adequacy of dialysis (as assessed by blood pressure control and laboratory and neurologic variables) and patient or technique survival. Renal transplant was the primary reason for discontinuing the assigned dialysis technique in both groups. The average number of hospitalizations per patient-year was 1.0 using continuous ambulatory peritoneal dialysis with a Y-connector and 0.6 per patient-year using continuous cyclic peritoneal dialysis (P = 0.02), with a mean duration of 10.8 and 9.6 days per admission, respectively (not significant). Peritonitis occurred significantly less often in those receiving continuous cyclic peritoneal dialysis (0.94 compared with 0.51 episodes per patient-year; P = 0.03). No difference in causative pathogens was observed. Exit site infection rate was 0.38 episodes per patient-year in both groups. CONCLUSION: In an unselected patient group, continuous cyclic peritoneal dialysis was accompanied by significantly lower rates of peritonitis and dialysis-related hospital admission, whereas it was as effective as continuous ambulatory peritoneal dialysis with a Y-connector for patient and technique survival.

In vitro compatibility of a 1.1% amino acid containing peritoneal dialysis fluid with phagocyte function.

The effects of a recently introduced peritoneal dialysis fluid (PDF) containing amino acids (AA) were compared with those of a glucose-based PDF (G-PDF) on viability and function of donor granulocytes (PMNs) in vitro. After 30 min incubation in the PDF, viability, assessed by trypan blue exclusion, and phagocytosis capacity (PC), tested in two assays using a fluorescein and a 3H-labeled Staphylococcus epidermidis strain, were significantly better in AA-PDF than in G-PDF (p < 0.002 in the 3H-assay). Bactericidal activity was not different in the PDFs. If pH of G-PDF was adjusted from 5.2 to neutral, differences in PC disappeared. In AA-PDF, PMN chemiluminescence (CL) response was significantly higher than in G-PDF (p < 0.003). At neutral pH, however, PMNs showed a significant stronger CL-response in 1.36% G-PDF than in AA-PDF (p < 0.05). These data suggest that this AA-PDF has little detrimental effect on phagocyte viability and function. The improved compatibility over G-PDF in in vitro tests seems to be pH dependent. The reduced chemiluminescence response compared to 1.36% G-PDF with neutral pH is possibly due to quenching by (one of the) amino acids and osmolarity.