[Effect of inflammation on clinical outcomes in dialysis patients]. / Effetto degli stimoli infiammatori sull' outcome clinico nei pazienti in dialisi.

There is a growing recognition that uremia is a proinflammatory condition. Chronic uremia-associated inflammation contributes to the pathogenesis of atherosclerosis, anemia, and cardiovascular calcification in patients with end stage renal failure. Many clinical and experimental evidences indicate that the higher the inflammatory status, the higher is morbidity, mortality and the incidence of chronic malnutrition. Aim of this review is to address the main clinical and experimental findings of the effect of chronic inflammation on clinical outcome in dialysis patients.

Improvement in exercise capacity after correction of anemia in patients with end-stage renal failure.

Changes in exercise tolerance occurring after correction of anemia with recombinant human erythropoietin in a group of patients with end-stage renal failure were evaluated. Ten patients, aged 29 +/- 11 years, on chronic hemodialysis treatment, with no associated diseases, were evaluated by cardiopulmonary bicycle exercise testing and M-mode, 2-dimensional and pulsed doppler echocardiography before and after anemia correction. After 1 and 3 months of therapy, hemoglobin plasma levels increased from 5.9 +/- 1.2 to 7.7 +/- 1.3 and 9.9 +/- 1.4 g/dl, with a concomitant increase in peak oxygen consumption (VO2) from 21.4 +/- 4.3 to 24.4 +/- 4.3 and 26.6 +/- 4.6 ml/kg/min and of VO2 at the ventilatory threshold from 15.0 +/- 3.7 to 17.3 +/- 3.7 and 16.8 +/- 3.4 ml/kg/min. After 3 months of therapy, systolic blood pressure significantly decreased both at peak exercise (159 +/- 35 to 134 +/- 22 mm Hg) and ventilatory threshold (140 +/- 27 to 123 +/- 19 mm Hg), whereas cardiac index at rest decreased from 3.3 +/- 0.7 to 2.8 +/- 0.5 liters/min/m2 and heart rate from 77 +/- 12 to 70 +/- 10 beats/min. However, no significant relation was found between hemoglobin plasma levels and peak VO2, whereas a significant relation was found between hemoglobin concentration and cardiac index at rest.

Cholesterol crystal embolism: A recognizable cause of renal disease.

Cholesterol crystal embolism, sometimes separately designated atheroembolism, is an increasing and still underdiagnosed cause of renal dysfunction antemortem in elderly patients. Renal cholesterol crystal embolization, also known as atheroembolic renal disease, is caused by showers of cholesterol crystals from an atherosclerotic aorta that occlude small renal arteries. Although cholesterol crystal embolization can occur spontaneously, it is increasingly recognized as an iatrogenic complication from an invasive vascular procedure, such as manipulation of the aorta during angiography or vascular surgery, and after anticoagulant and fibrinolytic therapy. Cholesterol crystal embolism may give rise to different degrees of renal impairment. Some patients show only a moderate loss of renal function; in others, severe renal failure requiring dialysis ensues. An acute scenario with abrupt and sudden onset of renal failure may be observed. More frequently, a progressive loss of renal function occurs over weeks. A third clinical form of renal atheroemboli has been described, presenting as chronic, stable, and asymptomatic renal insufficiency. The renal outcome may be variable; some patients deteriorate or remain on dialysis, some improve, and some remain with chronic renal impairment. In addition to the kidneys, atheroembolization may involve the skin, gastrointestinal system, and central nervous system. Renal atheroembolic disease is a difficult and controversial diagnosis for the protean extrarenal manifestations of the disease. In the past, the diagnosis was often made postmortem. However, in the last decade, awareness of atheroembolic renal disease has improved, enabling us to make a correct premortem diagnosis in a number of patients. Correct diagnosis requires the clinician to be alert to the possibility. The typical patient is a white man aged older than 60 years with a baseline history of hypertension, smoking, and arterial disease. The presence of a classic triad characterized by a precipitating event, acute or subacute renal failure, and peripheral cholesterol crystal embolization strongly suggests the diagnosis. The confirmatory diagnosis can be made by means of biopsy of the target organs, including kidneys, skin, and the gastrointestinal system. Thus, Cinderella and her shoe now can be well matched during life. Patients with renal atheroemboli have a dismal outlook. A specific treatment is lacking. However, it is an important diagnosis to make because it may save the patient from inappropriate treatment. Finally, recent data suggest that an aggressive therapeutic approach with patient-tailored supportive measures may be associated with a favorable clinical outcome.

Familial clustering of IgA nephropathy: further evidence in an Italian population.

Several lines of evidence suggest that genetic factors have an important role in the pathogenesis of immunoglobulin A (IgA) nephropathy. We report the prevalence of familial IgA nephropathy in a referral center in northern Italy and present the data on HLA genotypes in the families identified. Twenty-six of 185 patients (14%) with IgA nephropathy investigated in Brescia, Italy, were related to at least one other patient with the disease. Restriction fragment length polymorphism (RFLP) analysis of HLA-DR beta and HLA-DQ alpha and beta genes, as well as polymerase chain reaction-based oligonucleotide typing, was performed in family members. The 26 patients with IgA nephropathy belonged to 10 families. Familial relationships between the patients varied greatly, ranging from parent-child to sib-pair to more distant familial relationships. No common nephrotoxic factor was identified in the families. The intervals separating the apparent onset of disease in relatives with IgA nephropathy varied from 8 months to 13 years. In patients with a family history of IgA nephropathy, there was an increased incidence of HLA-DRB1*08 compared with those with sporadic IgA nephropathy. The study shows that a significant number of the patients with IgA nephropathy followed up in Brescia had a family history of disease. The fact that the Italian population, an ethnic group not previously examined, also presents an increased familial susceptibility to IgA nephropathy suggests that familial predisposition is a very common finding for IgA nephropathy. Thus, clinicians should become aware that IgA nephropathy may aggregate within families in a substantial number of cases. In addition, this subgroup of patients with IgA nephropathy offers an ideal opportunity to elucidate the molecular genetics of this disease.

Renormalization of high cardiac output and of left ventricular size following long-term recombinant human erythropoietin treatment of anemic dialyzed uremic patients.

To obtain information on the effects of the correction of uremic anemia on cardiac function and size, nine normotensive dialyzed patients were studied before, during and six months after the start of i.v. treatment with recombinant human erythropoietin (rHuEPO). Pulsed-doppler echocardiographic determinations of the cardiac index (CI) and M-Mode echocardiographic estimations of the indexed left ventricular end diastolic diameter (LVEDDi), interventricular septum (IVSi), left ventricular posterior wall (LVPWi), with calculations of the left ventricular mass index (LVMi), were made on every occasion. Mean (+/- SD) hemoglobin (Hb) concentration before rHuEPO was 5.9 +/- 1.3 g/dl and rose significantly (p less than 0.0001) up to the third month, then remained constant. Baseline CI (3.4 +/- 0.6 l/min/m2bsa) was significantly higher (p less than 0.0001) than in healthy subjects (2.5 +/- 0.5 l), and decreased after the third month to a value (2.8 +/- 0.5 l) no longer different from that of controls. From pooled baseline and third month data, an inverse relationship between Hb and CI was found (p less than 0.0001). Baseline LVEDDi (32.7 +/- 4.3 mm/m2bsa), IVSi (6 +/- 1.1 mm/m2bsa) and LVPWi (5 +/- 0.8 mm/m2bsa) were all significantly higher than in controls. After three months of therapy, the only change was a decrease in LVPWi while after six months all indices, including the LVMi, decreased to values no longer higher than in controls. From pooled baseline and six months data, an inverse relationship between Hb and LVMi was found (p less than 0.0001). We conclude that treatment of uremic patients by rHuEPO is able to renormalize their already increased cardiac output soon after correction of the anemia.(ABSTRACT TRUNCATED AT 250 WORDS)

CAPD viability: a long-term comparison with hemodialysis.

OBJECTIVE: To compare the long-term viability of continuous ambulatory peritoneal dialysis (CAPD) to that of hemodialysis (HD). DESIGN: Retrospective study of patients of our institution starting dialysis between January 1, 1981, and December 31, 1993, and surviving for at least 2 months. PATIENTS: Five hundred and seventy-eight new patients (51.3% on CAPD and 48.6% on HD). MAIN OUTCOMES STUDIED: Cox-adjusted assessment of patient and technique survival, and of technique success. Differences in results for two successive periods of time. RESULTS: Patient survival did not differ between CAPD and HD after adjusting for age and comorbidity, and significantly improved in the second part of the follow-up (1987-1993). Technique failure was significantly higher on CAPD, in which it was inversely related to age. The probability of a patient continuing on the first method of dialysis ("technique success") was significantly lower on CAPD than on HD, but the difference decreased progressively with age and disappeared in patients > or = 75 years. CONCLUSION: CAPD is as effective as HD in preserving life in uremic patients in the long-term, and gives better results in the older elderly. In adults, the lower technique success rate may not be a problem for patients with access to a good transplantation program; for others, this drawback must be weighed against the advantages of home treatment.

Comparison of long-term survival between hemodialysis and peritoneal dialysis.

We have reviewed the literature and our own center's results for patients on long-term continuous ambulatory peritoneal dialysis (CAPD) in comparison to results for patients on hemodialysis (HD). Contrary to recent American data showing one-year survivals to be worse on CAPD, the Canadian Registry and other studies show no significant difference in survivals on the two methods. Results are also conflicting for diabetics. Insufficient adjustments for age and case-mix variations are probably the most important causes for differences. For the general population, personal Cox-adjusted data show no difference between CAPD and HD up to ten-year follow-up, with very close curves for the adults and non-significant differences for the elderly. Old elderly (> 75 years) have better survival on CAPD in the first years of treatment. Dropout, which is higher on CAPD, decreases with age, and the patient retention on CAPD is worse than on HD for all patients, except the old elderly, for whom it is similar. These data were obtained in patients receiving a standard treatment, modified in order to give a more adequate dialysis dose only in recent years. The results of a prospective three-year study on the effect of nutritional [serum albumin and transferrin, normalized protein catabolic rate (PCRN), and subjective global assessment of malnutrition] and adequacy indices [Kt/V, creatinine clearance (Ccr), residual renal function] on patient survival on CAPD and HD are reported. Survival was not different for the two methods. Using the Cox analysis, nutritional indices did not affect survival whereas adequacy indices did. The effect of low serum albumin on survival was referable to the predialysis nutritional state. The similar survivals obtained on CAPD and HD, with Kt/V more or less than 1.0/treatment for HD and 1.7/week for CAPD, support the "peak concentration hypothesis" of Keshaviah et al. Survival in different groups of patients with different Kt/V and Ccr shows that the adequate dose on CAPD is Kt/V between 1.96 and 2.03 and Ccr > or = 70 L/week. A group of 26 patients who remained on CAPD treatment for more than eight years was also studied. Patient age and predialysis comorbidity were the most important factors affecting survival. Patients surviving longest had > 3 g/dL of serum albumin, > 0.8 g/kg/day of PCRN, a Kt/V > 1.6, and a weekly Ccr > 54L/week.

Hospitalization: CAPD versus hemodialysis and transplant.

We studied morbidity in 648 patients treated in our center in a ten-year period as indicated by duration of hospitalization: 232 patients were on CAPD, 188 on hemodialysis (HD) and 228 had cadaveric kidney transplants (Tx). Duration of hospitalization was divided into four groups according to its causes. The age of the patients on CAPD was 61 +/- 14 years, 53 +/- 17 on HD and 36 +/- 10 in the Tx group. The total follow-up was 629 patient-year (p-y) on CAPD, 458 p-y on HD and 928 p-y on Tx. The first admission was longer on CAPD (30 +/- 18 days) and on Tx (36 +/- 18 days) than on HD (18 +/- 12). After the first admission, the total days of hospitalization (days/patient-year, d/p-y) were more for CAPD than HD and Tx. Analysis of these data showed that the difference was due to peritonitis and to the different percentage of elderly patients in the CAPD group. With a reduction in the incidence of infectious complications (peritonitis, tunnel or exit-site), hospitalization in CAPD could be reduced to a length of time similar to that currently needed by HD and Tx patients. This can result in important cost-saving.

Which vascular access for chronic hemodialysis in uremic elderly patients?

The type of hemodialysis vascular access (fistula, graft, catheter) employed plays an important role in the results of dialysis treatment. Moreover, different complications can affect the vascular access and interfere with the morbidity and mortality of patients. The ideal vascular access is the Cimino Brescia fistula. Graft and catheter methods should be considered as 'second choice' because they present a higher incidence of complications, mainly due to thrombosis and infections. Finally, in elderly patients the vascular bed is frequently damaged and this may make it difficult to create a Cimino Brescia fistula. In a 5-year period, 140 elderly patients (>65 years) and 63 'young' patients (< 65 years) started dialysis treatment in our facility. In the elderly group, a native fistula was created in 88% of cases, whereas in the younger patients the percentage was 94% (p: NS). The grafts were, respectively, 11% in elderly and 6% in young patients. Only in one case, in one elderly patient, was a permanent catheter the first vascular access. We also report survival rate of the first vascular access, the incidence of thrombosis, and the need for creating another type of access. We suggest that a native fistula can be easily created in elderly patients and a 'second choice' access should be limited to a small proportion of patients.

Familial aggregation of primary glomerulonephritis in an Italian population isolate: Valtrompia study.

Hereditary factors are suspected to contribute to the pathogenesis of sporadic primary glomerulonephritis, but their contribution is difficult to delineate in the general population. We studied the prevalence of primary glomerulonephritis in an isolated population from the extreme northern Valtrompia valley, Northern Italy. Investigation of medical records, community urinary screening program and molecular characterization of the population's ancestry were performed; genealogies of affected individuals were researched. Forty-three patients with primary glomerulonephritis were identified: 25 had biopsy-proven disease (11 immunoglobulin A (IgA) nephropathy; eight mesangial proliferative glomerulonephritis without IgA deposits; four focal segmental glomerular sclerosis; two membranous nephropathy), and 18 had clinical glomerulonephritis. All 43 patients originated from three mountain villages (Collio, San Colombano, and Bovegno). In contrast, we found only four cases of primary glomerulonephritis in two nearby villages (Pezzaze and Tavernole) that shared similar population histories and lifestyles, demonstrating heterogeneity of risk factors for glomerulonephritis (P=3 x 10(-5)). All 43 affected individuals could be traced back to common ancestors (XVI-XVII centuries), enabling the construction of three large pedigree including three parent-child affected pairs and five affected siblings pairs. Molecular data showed lower genetic diversity and increased inbreeding in the Valtrompia population compared to the control population. Molecular and genealogical evidence of limited set of founders and the absence of shared nephritogenic environmental factors suggest that our patients share a common genetic susceptibility to the development of primary glomerulonephritis. Further molecular study of our families will offer the possibility to shed light on the genetic background underlying these glomerular disorders.

Adequacy, nutrition, and biocompatibility: their relevance on clinical outcome in haemodialysis patients.

Mortality and morbidity in haemodialysis patients remain high in spite of great improvements in technology that one would expect to improve patient survival. The general effort of the scientific community to minimise morbidity and mortality in haemodialysis patients has identified three main topics that can influence patient outcome and well-being: the dialysis dose, nutrition, and biocompatibility of the dialysis procedure. The aim of this review is to provide a critical assessment of the current clinical evidence supporting a role for each one of these three main factors on patient outcome.

Effect of age on protein catabolic rate, morbidity, and mortality in uraemic patients with adequate dialysis.

To test the validity of the assumption that the protein catabolic rate (PCRn g/kg/day) is dependent on the normalized dose of dialysis (Kt/V urea), and to try to define the characteristics of the patients in the undefined domain A of the mechanistic map of the National Cooperative Dialysis Study (NCDS), which should include patients with adequate amount of dialysis but inadequate PCRn, urea kinetic modelling was performed over 12 months on 85 patients undergoing haemodialysis. All the patients were managed to maintain a Kt/V urea > or = 0.9. During the entire period of study the total number of hospitalizations and the number of days of hospitalization were recorded. Total serum proteins and serum albumin concentrations were measured at the start and at the end of the study. The results of the study show that there was no correlation between Kt/V and PCRn nor between Kt/V and patient's age, but there was a strong inverse correlation between age and PCRn (r = 0.578; P < 0.0001). Further division of the patients into four groups according to age showed that the lowest values of PCRn were for the group of patients > or = 75 years old. Twelve patients with PCRn < or = 0.8 and Kt/V > or = 0.9 were included in domain A of the mechanistic map. Eleven (92%) of these 12 patients were > or = 65 years old. No correlations were found between the total number of hospitalizations, the total days of hospitalization, Kt/V, time on HD, body weight and PCRn by multiple regression analysis, while the inverse correlation between PCRn and age was confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of hematocrit in efficiency of dialysis.

To test the role of hematocrit (Hct), particularly when in the nearly normal range, on efficiency of dialysis, we analyzed the urea kinetics for 36 metabolically and hematologically stable patients on regular dialysis treatment and for 7 patients from this group before and after 3 months of treatment with human recombinant erythropoietin (rHuEPO). The volume of distribution of urea (V), the dialyzer clearance (Kd) and Kt/V were plotted against Hct. Hct showed a significant inverse correlation with Kd (r = 0.479, p = 0.003) and Kt/V (r = 0.572, p = 0.0002). Further division of the patients into groups with respect to Hct showed that the lowest Kt/V values were in the group with Hct greater than or equal to 37%. In the patients treated with rHuEPO, Hct rose from 18 +/- 1 to 35 +/- 5% (p less than 0.0001), and Kt/V decreased from 1.22 +/- 0.21 to 1.09 +/- 0.18 (p = 0.037). We conclude that Hct exerts a negative influence on efficiency of dialysis as evaluated by Kt/V. This is important for patients with normal or nearly normal Hct levels as well as for patients treated with rHuEPO, for whom normalization of Hct is pursued.

Adequacy of dialysis reduces the doses of recombinant erythropoietin independently from the use of biocompatible membranes in haemodialysis patients.

BACKGROUND: The effect of the adequacy of dialysis on the response to recombinant human erythropoietin (rHuEpo) therapy is still incompletely understood because of many confounding factors such as iron deficiency, biocompatibility of dialysis membranes, and dialysis modality that can interfere. METHODS: We investigated the relationship between Kt/V and the weekly dose of rHuEpo in 68 stable haemodialysis (HD) patients (age 65+/-15 years) treated with bicarbonate HD and unsubstituted cellulose membranes for 6-343 months (median 67 months). Inclusion criteria were HD for at least 6 months, subcutaneous rHuEpo for at least 4 months, transferrin saturation (TSAT) > or = 20%, serum ferritin > or = 100 ng/ml, and haematocrit (Hct) level targeted to 35% for at least 3 months. Exclusion criteria included HBsAg and HIV positivity, need for blood transfusions or evidence of blood loss in the 3 months before the study, and acute or chronic infections. Hct and haemoglobin (Hb) levels were evaluated weekly for 4 weeks; TSAT, serum ferritin, Kt/V, PCRn, serum albumin (sAlb), and weekly dose of rHuEpo were evaluated at the end of observation. No change in dialysis or therapy prescription was made during the study. RESULTS: The results for the whole group of patients were: Hct 35 +/- 1.2%, Hb 12.1 +/- 0.6 g/dl, TSAT 29 +/- 10%, serum ferritin 204 +/- 98 ng/ml, sAlb 4.1 +/- 0.3 g/dl, Kt/V 1.33 +/-0.19, PCRn 1.11+/- 0.28 g/kg/day, weekly dose of rHuEpo 123 +/- 76 U/kg. Hct did not correlate with Kt/V, whereas rHuEpo dose and Kt/V were inversely correlated (r = -0.49; P < 0.0001). Multiple regression analysis with rHuEpo as dependent variable confirmed Kt/V as the only significant variable (P < 0.002). Division of the patients into two groups according to Kt/V (group A, Kt/V < or = 1.2; group B, Kt/V > or = 1.4), showed no differences in Hct levels between the two groups, while weekly rHuEpo dose was significantly lower in group B than in group A (group B, 86 +/- 33 U/kg; group A, 183 +/- 95 U/kg, P < 0.0001). CONCLUSIONS: In iron-replete HD patients treated with rHuEpo in the maintenance phase, Kt/V exerts a significant sparing effect on rHuEpo requirement independent of the use of biocompatible synthetic membranes. By optimizing rHuEpo responsiveness, an adequate dialysis treatment can contribute to the reduction of the costs of rHuEpo therapy.

Differing dialysis treatment strategies and outcome.

The choice of a dialysis treatment depends on many factors, both medical and non-medical. A full and rational treatment requires easy access to a transplantation programme and to all dialysis modalities, extracorporeal or peritoneal. Presently, haemodialysis (HD) is used almost exclusively for in-centre or limited care treatment, peritoneal dialysis (PD) being preferred for home treatment. On HD, bicarbonate buffer is used in preference to acetate. Mixed convective-diffusive HD techniques have a very limited utilization world-wide because of their cost. Use of PD and automated PD continues to grow, although slowly. In our single-centre experience on a large number of patients, 10-year patient survival is not different on CAPD and HD, and there is initial lower risk of death on CAPD for patients > or = 75 years of age. Drop-out from CAPD has increased in recent years, mainly due to the patient/partner 'burn-out'. Drop-out is less for the elderly, and the difference in modality change between CAPD and HD decreases with increasing patient age, suggesting a clear indication for CAPD in the elderly, or in adults waiting for a transplant. The clinical background, e.g. the presence of diabetes mellitus, cardiovascular disease, dyslipidaemia or obesity, is also important in the choice of method.

Blood volume changes during three different profiles of dialysate sodium variation with similar intradialytic sodium balances in chronic hemodialyzed patients.

The aim of this study was to evaluate the effects on blood volume (BV) preservation of three different profiles of dialysate sodium variation with similar intradialytic sodium balances. Ten uremic patients aged 50 +/- 11 years receiving regular bicarbonate hemodialysis for 49 +/- 57 months were studied. Each patient underwent three hemodialysis treatments with different modalities of dialysate sodium profiles: constant sodium hemodialysis (CHD), high-low sodium hemodialysis (H-LHD), and low-high sodium hemodialysis (L-HHD). In CHD, the dialysate sodium concentration was 141 mEq/L and did not change during treatment. In H-LHD and L-HHD, the dialysate sodium concentration at the start of dialysis was 160 mEq/L and 133 mEq/L, respectively, and remained constant for 60 minutes. At this time, a single-step break point of variation of dialysate sodium concentration occurred. The dialysate sodium concentration changed according to a model aimed to keep identical the amount of dialysate sodium exchanged in the three different dialysis procedures. The duration of hemodialysis, the blood flow rate, the dialysate flow rate, and the dialysis membrane were the same for all three different hemodialysis modalities. The ultrafiltration rate was kept constant during treatment. Total dialysate collection and intradialytic sodium balance were calculated for each hemodialysis session. Blood pressure and heart rate were monitored at 10-minute intervals; percent reductions of BV (%R-BV) were continuously monitored by an online optical reflection method (Hemoscan; Hospal-Dasco, Medolla, Italy). The results have shown a lower intradialytic %R-BV with H-LHD compared with L-HHD and CHD. No differences in total ultrafiltration rate, systolic and diastolic blood pressures, and heart rate were observed among the three different dialysis procedures. The total dialysate sodium collected and the intradialytic sodium balances were very similar among the three different dialysis procedures, confirming the accuracy of the precision of the sodium model used. The H-LHD sodium profile may be a useful tool in the prevention of excessive %R-BV and of dialysis intolerance episodes.

Influence of protein catabolic rate on nutritional status, morbidity and mortality in elderly uraemic patients on chronic haemodialysis: a prospective 3-year follow-up study.

It has been recently reported that elderly chronic haemodialysis (CHD) patients have a reduced protein catabolic rate (PCRn) in spite of an adequate Kt/V. However until now the long-term consequences of this fact on the nutritional status, morbidity, and mortality were not known. This prospective study evaluates, over a period of 3 years, the effect of the reduced PCRn on some nutritional parameters, morbidity mortality in CHD patients older than 65 years with adequate and stable Kt/V. Over the period 1990-1993 we evaluated 42 CHD patients over 65 years (mean +/- SD 72 +/- 5 years). PCRn, total serum proteins, serum albumin concentration, body weight, body mass index (BMI) and serum transferrin were determined at the start of the study and followed yearly until the end of observation. The incidence of hospitalization/patient-year, the mortality rate and the causes of death were also recorded. All the patients were managed to maintain a Kt/V > 0.9 throughout the study. Twenty-two patients (Group A), mean age 70 +/- 4 years, completed the entire period of observation. Their Kt/V was 1.10 +/- 0.12, PCRn was 0.95 +/- 0.12 g/kg/day, and serum albumin concentration was 40.2 +/- 1.5 g/l, and these did not change significantly. The other parameters also remained stable over time. Twenty patients (Group B) died. Their mean age was 74 +/- 6 years. This group's Kt/V was 1.11 +/- 0.15, PCRn was 0.94 +/- 0.18 g/kg/day, and serum albumin concentration was 39 +/- 3.1 g/l, and there were no significant variations between the start and the end of observation for all the parameters studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Is CAPD competitive with haemodialysis for long-term treatment of uraemic patients?

Although there are only 10 years of clinical experience with CAPD, compared to about 30 years of clinical practice with haemodialysis, it is time to compare the results obtained from the two methods. In this review, after briefly summarising the state of the art for some worrisome aspects of CAPD (peritonitis, loss of ultrafiltration and peritoneal clearance, malnutritional status), the ability of CAPD and haemodialysis to control the uraemic abnormalities are compared. Anaemia, blood pressure, cardiac function, renal bone disease, beta 2-microglobulin, and uraemic neuropathy are examined in the light of our personal experience and the literature; data so far published seem to indicate that the two methods are roughly similar for controlling these conditions. A survey of the studies comparing patient and method survival is also included. Patient survival on CAPD or on haemodialysis does not differ by more than 6 years. Method survival is better for haemodialysis; this is primarily due to the high drop-out rate from CAPD because of peritonitis, and the difference is very much reduced in CAPD centres with a low incidence of peritonitis. On the whole, CAPD seems to be able to compete, sometimes favourably, with haemodialysis. However, in our opinion the two methods are not in competition; each has its preferential indications, limits and complications, and both should be offered to uraemic patients in accordance with their medical or social needs. One should be ready to shift the patient from one method to the other when necessary, either for short periods of time or indefinitely.

A prospective comparison of bicarbonate dialysis, hemodiafiltration, and acetate-free biofiltration in the elderly.

Hemodiafiltration (HDF) and more recently acetate-free biofiltration (AFB) have shown good blood purification and cardiovascular stability in young and middle-aged hemodialysis patients. It is not clear if this is also valid for elderly patients. Twelve patients aged more than 70 years (mean age +/- SD, 76 +/- 4 years) on regular dialysis for at least 5 months were treated with bicarbonate dialysis (BD), HDF, or AFB in a randomized sequence and prospectively followed for 6 months (72 dialysis sessions/patient) for each procedure. The dialysis solution (containing bicarbonate), blood flow rate, and dialysate flow rate were the same with all the methods. During HDF and AFB solutions containing bicarbonate at a concentration of 27 to 30 mEq/L and 145 mEq/L, respectively, were infused postdilution at a rate of 66 +/- 7 mL/min and 2.81 +/- 0.12 L/hr, respectively. During the period of observation we evaluated the number of intradialytic hypotensions, the episodes of nausea, vomiting, headache (dialysis intolerance), body weight, the interdialysis weight gain, the duration of the dialysis session, the number of hospitalizations/patient, and the length of hospitalization/patient. At the end of each observation period we determined: Kt/V, protein catabolic rate, acid base balance, serum creatinine, serum calcium, serum phosphorus, alkaline phosphatases, and serum intact parathyroid hormone. After the switch from BD to either HDF or AFB, the results have shown a significant reduction of dialysis hypotension episodes (18 percent on BD, 14 percent on HDF, and 13 percent on AFB; BD v HDF, P = 0.001; BD v AFB, P = 0.0001; and HDF v AFB, P = NS) and of dialysis intolerance (3.3 percent on BD, 1.3 percent on HDF, and 1.1 percent on AFB; BD v HDF, P = 0.021; BD v AFB, P = 0.019; and HDF v AFB, P = NS). Kt/V improved significantly after the switch from BD to either HDF or AFB (1.17 +/- 0.06 on BD, 1.32 +/- 0.12 on HDF, and 1.32 +/- 0.13 on AFB; BD v HDF, P = 0.021; BD v AFB, P = 0.003; HDF v AFB, P = NS). Protein catabolic rate also improved in HDF and AFB compared with BD (0.90 +/- 0.12 on BD, 1.03 +/- 0.15 on HDF, and 1.04 +/- 0.14 on AFB; BD v HDF, P = 0.001; BD v AFB, P = 0.009; and HDF v AFB, P = NS). AFB showed a better correction of acidosis compared either with BD or HDF (serum bicarbonate, 20.3 +/- 1.1 mEq/L on BD, 20.8 +/- 2.2 mEqL on HDF, and 22.2 +/- 2.4 mEq/L on AFB; BD v HDF, P = NS; BD v AFB, P = 0.01; and HDF v AFB, P = 0.030). The other parameters observed did not differ. In conclusion HDF and AFB show a better dialysis efficiency and a better hemodynamic tolerance compared with BD. This fact is associated with an improvement in protein intake as assessed by kinetic criteria. Acetate-free biofiltration has the further advantage of a better control of the acid-base balance compared with BD and HDF. HDF and AFB are useful dialytic options to traditional BD hemodialysis even in patients older than 70 years.