Anxiety, depression and emotional profile in renal transplant recipients and healthy subjects: a comparative study.

BACKGROUND: Renal transplantation is a well established treatment for end-stage renal disease. However, recipients have been shown to develop emotional distress and affective disorders, such as anxiety and depression, associated with a compromised quality of life. Some accounts report an improvement of affective disorders after transplantation, others draw opposite conclusion. METHODS: The present cross-sectional study selected 42 transplant recipients and 42 control subjects matched for gender, age, educational background, and marital status. Symptoms of anxiety, depression and general emotional profiles were compared using the Zung Self-Rating Anxiety Scale, the Beck Depression Inventory (BDI), and the Affective Neuroscience Personality Scale (ANPS), a self-report inventory that evaluates 6 neurally based affective tendencies: seeking, caring, and playfulness (positive affects) and fear, anger, and sadness (negative affects). RESULTS: No significant differences were observed between transplanted patients and controls in scores for anxiety and depression, as evaluated with Zung and BDI scales. However, transplanted patients scored significantly lower than control subjects in fear and anger scales and in general negative emotions. Transplant recipients did not display any symptom of anxiety or depression, however, a significant reduction in negative affect, evaluated through the ANPS scale revealed psychological distress. CONCLUSIONS: These findings suggest that affective profile in transplanted patients should be more extensively examined to review all facets in their mental and emotional assessment, especially regarding the role played by this emotional pattern in complying with medical treatment, which is well known to be a clinically critical feature of these patients.

[Should dialysis be for all? Yes indeed!]. / Ma la dialisi deve essere per tutti? Certo che si'!

Clinically compromised patients who must undergo chronic dialysis are, in general, at risk because the procedure can be difficult to perform and give poor results in terms of survival and of rehabilitation. However, it is dialysis of the very elderly which is routinely characterized by misgivings about the indication for and limits of the technique. Patients older than 75 years of age currently represent more than 35% of the population that begin dialysis in most European registries. In our center at least 30 very old patients begin dialysis every year, which represents 45% of the total incident patients. About 30% of these patients, because of severe physical and/or mental disability, often associated with a situation of social deprivation, rarely achieve true clinical stability and depend upon outside caregivers in order to survive. The treatment of these patients strains the resources of the health and social structure, as well as the Nephrology Division, whose organization can be disrupted by their urgent needs, such as hospitalization, transportation, convalescent care, etc. Despite these difficulties and a mean survival of only 28 months, the global clinical conditions of patients older than 75 years of age are not much different than patients in the age bracket of 65 to 75 years. In fact, excluding patients older than 85 years of age (a category which geriatricians consider separately), the survival and rehabilitation of the very elderly appear similar to those of patients 65 to 75 years of age. Many of the clinical problems of the dialyzed elderly, such as sensory, mental and functional impairment, are the result of advanced age per se rather than of uremia or of dialysis. Therefore, ethical considerations of dialysis and of health maintenance in the very elderly are similar to those presented by patients who are afflicted by other serious diseases such as cancer, heart failure, or extensive stroke. As a result of modern technology and the advancement of our clinical knowledge, it is difficult to conceive of a true motive to not dialyze a patient--whether very elderly or any other patient in critical conditions--except in situations of futility or the impossibility to attain a reasonable quality of life. Thus, the true nature of the debate regarding the indications or the limits of dialysis in developed countries is not economic, technical nor clinical, but ethical. The challenge for the Nephrologist is to balance the need to alleviate human suffering and the institutional support that society can offer, which is the "bottom line" which unifies dialysis for the very elderly with every other therapy which prolongs life in tenuous conditions.

[Census 2004 of the Italian Renal and Dialysis Units. Veneto, Friuli Venezia Giulia and Trentino Alto Adige]. / Censimento 2004 dei Centri di Nefrologia e Dialisi Italiani. Veneto - Friuli Venezia Giulia - Trentino Alto Adige.

The Italian Society of Nephrology (SIN) promoted a national survey of the Renal and Dialysis Units using an online questionnaire on some aspects of structural, technological and personnel resources, as well as organisation and activity. The major aim of this initiative was to obtain a reference benchmark on a national and regional basis. In this paper the data of the northestern regions of Italy (Veneto, Friuli-Venezia Giulia and Trentino-Alto Adige) are reported and compared with the recently published results of the northwestern regions (Piedmont, Liguria and Valle d'Aosta). From an epidemiologic point of view, the prevalence of dialysis patients was 534 pmp (per million population) in Veneto, 667 pmp in Friuli VG and 545 in Trentino AA, the prevalence of transplanted patients was 265, 294 and 404 pmp, respectively; the incidence of dialysis patients was 137, 182 and 130 pmp; gross mortality was 12.5, 14.3 and 16.5%; the distribution of vascular accesse in prevalently dialysis patients was: arteriovenous fistulas = 84.5, 70.4 and 80.9%, central venous catheters = 10.6, 20.0 and 10.2%, vascular graft = 4.9, 9.6 and 8.8%. Regarding structural resources, the distribution of hospital bed numbers was 38, 42 and 43 pmp; dialysis places were 137, 181 and 172 pmp. Human resources were given by renal physicians = 28.3, 38.2 and 23.6 pmp and renal nurses = 138, 200 and 172 pmp; each renal physician took care of 19, 17 and 23 dialysis patients and each renal nurse cared for 3.9, 3.3 and 3.2 dialysis patients. Activity data showed 1436, 1328 and 974 pmp hospital admissions, kidney biopsies were 106, 114 and 31 pmp. Overall, the Italian Northeast shows a significantly lower prevalence and incidence of end-stage renal disease patients than the Northwest; on the contrary, the incidence of patients with acute renal failure is significantly higher. In the Italian Northeast a significantly lower number of hospital beds devoted to renal patients is observed, while dialysis places are more frequent. In the Northeast fewer renal physicians are present than in the Northwest, whereas renal nurses are equivalent if related to the number of dialysis patients. Activity indexes, intended as amount of hospital admissions and renal biopsies standardised per population, are less significant in the Northeast. The results of the survey in Veneto, Friuli VG and Trentino AA show some discrepancies in the treatment of chronic kidney disease between the three regions and even more among different areas of Italy. Despite similar health care models, a relevant inequality in health care resources is evident.

[Update of the Italian Society of Nephrology Project No. 1 of the 2004-2006 SIN programme]. / Update sul progetto SIN n. 1 del programma SIN 2004-2006: qualità e accreditamento delle strutture di nefrologia, dialisi e trapianto.

In the last few years the Italian Society of Nephrology has addressed many technical-scientific and management aspects to better patient satisfaction. Project No. 1 of the 2004-2006 programme on 'Quality and Accreditation of National Renal Units' focuses on four essential points. The first is the questionnaire mailed to all the Presidents and Regional Delegates on the relationship between Nephrology units, Local Government Health-System and the Regional Healthcare Agency. The results evidence that the 'political' decision-making power of nephrologists decreases in the absence of a national strategy. The second point, in collaboration with the National Census Group, includes the quality analysis and the standardization of resources (human and structural) and management of the Renal Units. The third point is based on 'Educational Courses for Quality and Accreditation' held in Rome (3-5 October 2005: L'Accreditamento all'Eccellenza dell'Unita' Operativa di Nefrologia, Dialisi e Trapianto; 17-19 October 2005: Il Manuale di Accreditamento della Specialità di Nefrologia). The courses aim at training members responsible for each region to hold courses in their specific region to create a network including each single Renal Unit to create an acceptable homogenous language on the models of analysis and on the correct use of 'The Guide for Excellence Accreditation'. The fourth point concerns both the on-line Guide for Excellence Accreditation and 'Peer Review Accreditation' and the NEQUASY (Nephrology Quality System) project. The manual must be 'user friendly' allowing each Centre to self-evaluate using national and regional standards.

[Frail elderly in hemodialysis]. / L'anziano fragile in dialisi.

A new category of patients aged >75 yrs, namely the elderly, is now being freely admitted to hemodialysis (HD) and this category is becoming predominant. The absence of systematic studies makes this patient category almost indistinguishable from other categories, even though its peculiarity is now evident. At least 30-40% of individuals in this age bracket are expected to be dependent and/or frail, but the incidence of frailty is likely to be higher in the elderly undergoing HD. Due to severe physical and/or mental impairment and often because of strong social hardships, these patients rarely experience clinical stability and are dependent on third parties for their survival. Their care produces complex problems for welfare services and this has proved responsible for modifying the organization of renal care units. These repeated patient admissions to hospital are filling nephrology facilities, and the dialysis management -- mainly concerning outpatients -- requires a much greater use of facilities and staff than normal if compared to average dialysis patients. In 112 elderly patients consecutively admitted to the dialysis program over a period of 10 yrs, we identified 35 dependent or frail patients (31.2%), even taking into consideration only extreme degrees of infirmity. Dependence proved to be the only clinical parameter associated with survival (mortality at 6 months 23.6 vs. 10.6%, p<0.01; Kaplan-Meier survival curves, p<0.03 log-rank test), while comorbidities -- in particular cardiovascular -- that usually affect dialysis mortality rates, did not seem to be discriminating risk factors in the elderly. More precisely, with the confirmation of these data through wider case studies, the idea will be reinforced that, also in dialysis, the elderly must be constantly monitored for dependence and frailty, as is the case in any exclusively geriatric field. Prevention, as well as a therapeutic approach specifically modeled on these conditions, could help to improve the prognosis of this patient category, which is particularly difficult to deal with and is becoming predominant in dialysis units.

[The hemodiafiltration with infusion of acetate-free dialysis fluid can modify the inflammatory response in patients "high responders" to inflammatory stimuli?]. / Il trattamento in emodiafiltrazione con infusione di liquido di dialisi (PHF acetate free) può modificare la risposta infiammatoria in pazienti già identificati come "high responders" a stimoli infiammatori?

PURPOSE: This study aimed to verify the effects of paired hemodiafiltration on-line (PHF-AF) on inflammation in patients who were "high responders" to inflammatory stimuli: elevated C-reactive protein (CRP), genetic polymorphisms influencing a low transcription for interleukin-10 (IL-10) and a high transcription for IFN-gamma. METHODS: Ten patients selected as high responders for IFN-gamma and low responders for IL-10 were included in a crossover study to compare PHF-AF and standard bicarbonate hemodialysis (BHD). At study entry and before the start of each dialysis session the following examinations were performed: CRP, albumin, fibrinogen, ferritin, transferrin, prealbumin and serum levels of IL-6, IL-10, IFN-gamma, tumor necrosis factor-alpha (TNF-alpha). After the 1st and 3rd week of the study, the blood samples were also collected after the dialysis session. RESULTS: . There was a significant reduction in albumin and prealbumin in PHF-AF patients during the study; none of the other parameters were changed in both patient groups. CRP tended to be elevated after dialysis in both PHF-AF and BHD. While IL-6, IL-10 and IFN-gamma were unchanged during the dialysis session, there was a significant variation in TNF-alpha levels, which were increased in BHD (from 10.9 +/- 3.1 to 14.7 +/- 4.1 pg/mL; p=0.004) and reduced in PHF-AF (from 11.9 +/-2.8 to 6.3 +/- 2.2 pg/mL; p=0.0004). CONCLUSION: Although the cytokine levels were unchanged during the study in both BHD and PHF-AF, the modification of TNF-alpha during the dialysis session was considered as inflammatory significance.

[Role of iron deficiency in erythropoietin sensitivity in dialysis patients with elevated C-reactive protein]. / Ruolo della carenza marziale sulla sensibilita' all eritropoietina nei pazienti in dialisi con proteina C reattiva elevata.

BACKGROUND: Chronic inflammation is a well-known cause of hyporesponsiveness of the bone marrow to erythropoietin (Epo). Factors which contribute to Epo resistance in the presence of inflammation include inhibition of erythroid precursor proliferation and functional iron deficiency induced by inflammatory cytokines. The specific role of iron deficiency in this clinical context, however, has not yet been clarified. METHODS: Our dialysis population consisted of 200 patients, from which 163 (91 males, mean age 67 +/- 12 years) who had been in dialysis for at least 4 (mean 62.4 +/- 71) months were selected for further study. Two groups were defined on the basis of C-reactive protein (CRP) concentrations: Group A (normal CRP < 5 mg/L; 78 patients) and Group B (elevated CRP > 15 mg/L; 43 patients). The remaining 42 patients with CRP in the range of 5 to 15 mg/L were excluded from the study. RESULTS: Erythropoietin dose and the parameter EpoDose/hemoglobin (Hb) were both greater in Group B (dose: 150 +/- 65 vs. 106 +/- 56 U/kg, p<0.001; EpoDose/Hb: 14.0 +/- 6 vs. 9.8 +/- 6, p<0.001. The two groups were stratified on the basis of transferrin saturation (tSAT) greater or less than 20%: A1 (tSAT > 20%, n = 52), A2 (tSAT < 20%, n = 26), B1 (tSAT > 20%, n = 19) and B2 (tSAT < 20%, n = 24). Erythropoietin dose and EpoDose/Hb were lower in A1 compared to A2 (dose: 96 +/- 52 vs. 124 +/- 6 U/kg, p<0.05; EpoDose/Hb: 8.4 +/- 5 vs. 12.4 +/- 7, p < 0.05), whereas in the B subgroups the variables were equally elevated (dose: 151 +/- 71 vs 142 +/- 59 U/kg, ns; EpoDose/Hb: 14.4 +/- 7 vs. 13.6 +/- 6, ns). Patients in subgroups A2 and B2 were treated with intravenous Fe gluconate 31 mg after each dialysis session for 6 months. Erythropoietin dose and EpoDose/Hb were significantly reduced only in subgroup A2 with normal CRP (dose: from 126 +/- 55 to 95 +/- 52 U/kg, p < 0.05; EpoDose/Hb: from 12.4 +/- 7 to 8.4 +/- 5, p < 0.05), whereas no improvement was observed in subgroup B2 with elevated CRP (dose: from 142 +/- 59 to 151 +/- 65 U/kg, ns; EpoDose/Hb: from 13.6 +/- 6 to 14.4 +/- 7, ns). CONCLUSIONS: Our data demonstrate that dialysis patients with CRP greater than 15 mg/L require an erythropoietin dose approximately 40% higher than patients with normal CRP, both in the presence and absence of iron deficiency. Iron therapy in patients with normal CRP and tSAT < 20% significantly improved the response to erythropoietin, but was completely ineffective in patients with increased CRP. These results suggest that functional iron deficiency plays a marginal role in resistance to erythropoietin observed in patients with elevated CRP concentrations.

[Thermal energy balance during hemodialysis: the role of the filter membrane]. / Studio del bilancio termico durante la dialisi: ruolo svolto dalla membrana dei filtri.

BACKGROUND: Body temperature tends to increase during conventional haemodialysis; this might interfere with normal cardiovascular response to dialytic ultrafiltration, thus facilitating the occurrence of symptomatic hypotension. Putative factors responsible for changes in thermal balance during haemodialysis include heat load from the dialysis bath, reduction in convective heat loss secondary to skin vessel vasoconstriction, heat overproduction due to central stimulation by bioincompatibility reactions to the filter membranes. The aim of the present study was twofold: to define thermal energy balance (ET) during dialysis and to investigate the effect of membrane bioincompatibility on energy balance METHODS: We measured ET in 12 patients (9M, 3F) during two identical dialysis sessions, differing only in the membrane composition of the filters used: cuprophane 1.3- 1.6 mq and LF polysulphone 1.3- 1.6 mq. Thermal energy balance studies were performed by the Blood Temperature Monitor (Fresenius Medical Care) under conditions in which the core temperature of the patients was maintained unchanged from the start to the end of the dialysis procedure. RESULTS: Arterial blood temperatures were constant, while dialysate and venous blood temperatures progressively decreased (from 36.9 to 35.4 C and from 36.5 to 35.1 C for cuprophane; from 36.9 to 35.2 and from 36.9 to 35.1 for polysulphone membrane). Mean thermal energy transfer was negative (removal of energy from the patients to the extracorporeal circuit) with both filters, equal to 146 KJ with cuprophane and to 163 KJ with polysulphone. When a stepwise multiregression analysis was applied, hourly energy transfer (ET) was significantly and independently correlated with both ultrafiltration rate (UF=% b.w.) and heart rate changes (HR) according to the equation: ET= -92.03+41.29 UF+1.04 HR (p<0.0003). Conclusions. In this study we present experimental evidence that increased body temperature during dialysis is not caused by heat load from the dialysis bath, nor by heat over production secondary to bioincompatibility reactions. Consequently, haemodynamic responses to dialytic ultrafiltration may be regarded as the main regulatory factor of thermal balance.

[Case report: reversible acute renal failure following therapy with both ketorolac (non-selective non-steroidal anti-inflammatory drug NSAID) and celecoxib (COX-2 selective) in the same patient]. / Caso clinico: insufficienza renale acuta reversibile sia da FANS non selettivo (ketorolac) sia da COX-2 inibitore (celecoxib) nello stesso soggetto.

BACKGROUND: We present the case of acute renal failure complicating the course of therapy with both ketorolac (non-selective Non-Steroidal Anti-inflammatory Drug, NSAID), and celecoxib (COX-2 Selective Inhibitor) in an elderly woman with chronic liver disease, heart failure and chronic renal failure. The main effect of NSAIDs is the inhibition of cyclooxygenase (COX), the enzyme involved in prostaglandins synthesis. The nephrotoxicity of NSAIDs is linked to this effect since prostaglandins not only act in response to inflammatory stimuli, but also play a role as modulators of some physiological renal functions. Under conditions of reduced renal perfusion, acute renal failure secondary to NSAIDs use may occur if the vasoconstrictive forces stimulated to maintain the filtrating function are not balanced by prostaglandin-induced vasodilatation. About ten years ago, two COX isoforms were demonstrated: COX-1 whose products are involved in regulating physiological functions and COX-2 which is expressed by a number of inflammatory stimuli. The discovery of molecular differences between COX-1 and COX-2 allowed the development of pharmacological agents selectively inhibiting COX-1 or COX-2. Selective inhibitors of COX-2 are now available. However, COX-1 products are involved in inflammatory reactions, whereas COX-2 products play a physiological role in many tissues and organs, including the kidney. These observations raised many doubts regarding the renal safety of COX-2 Inhibitors before they became commercially available. These doubts have been recently confirmed in the Literature. CONCLUSIONS: The case we report seems to confirm that, in patients at risk, the renal adverse effects of non-selective NSAIDs and of COX-2 Inhibitors could be the same due to the similar physiological role of COX-1 and COX-2-dependent prostaglandins.

Validation of a simple method for assessing sodium intake in dialysis patients.

It has been reported that sodium intake can be estimated in dialysis patients by the increment in the body sodium pool from the end of a dialysis session to the beginning of the following one. To verify the reliability of this method we compared the sodium intake, estimated by the interdialytic changes in plasma sodium concentration (C) and body water volume (V), to sodium removal during three consecutive sessions. For this purpose we investigated 9 nondiabetic patients, 5 females and 4 males, under chronic hemofiltration treatment. Sodium intake was estimated by the formula (C(pre) V(pre)) - (C(post) V(post)) using a flame photometer and electrical bioimpedance to determine the plasma sodium concentration and total body water, respectively. Sodium removal was calculated by the difference between sodium loss into the ultrafiltrate and sodium gain with the reinfusion fluid. The mean values of sodium intake calculated during the three intervals corresponded with the sodium losses measured during the three hemofiltration sessions in each patient (338+/-55 vs. 329+/-67 mEq; r = 0.92, p<0.0001). A direct relationship was also observed between sodium intake and both interdialytic body weight increase (r = 0.89, p< 0.0001) and fluid loss during the sessions (r = 0.88, p<0.0001). This data demonstrates that sodium intake can be properly estimated by the interdialytic changes in body water and plasma sodium concentrations. They also suggest that fluid intake may be influenced by sodium consumption and that sodium intake monitoring could be useful for the control of excessive interdialytic fluid gain.

Dynamic magnetic resonance imaging in the assessment of chronic medical nephropathies with impaired renal function.

We examined the value of dynamic magnetic resonance imaging (MRI) in chronic renal disease with renal insufficiency. In 33 consecutive patients (21 vascular nephropathy, 12 glomerular nephropathy) MRI was performed using a 1.5-T unit and a body coil, with SE T1-weighted (TR/TE = 600/19 ms) and dynamic TFFE T1-weighted sequences (TR/TE = 12/5 ms, flip angle = 25 degrees ) after manual bolus injection (via a cubital vein) of 0.1 mmol/kg Gd-DTPA-BMA. Morphological evaluation was performed in unblinded fashion by three radiologists, evaluating renal size, cortical thickness, and corticomedullary differentiation. Functional analysis was performed by one reviewer. Time-signal intensity curves, peak intensity value (P), time to peak intensity (T), and the P/T ratio were obtained at the cortex, medulla, and pyelocaliceal system of each kidney. The relationship of these parameters to serum creatinine and with creatinine clearance was investigated. A good correlation between morphological features of the kidneys and serum creatinine values was found. Morphological findings could not distinguish between vascular and glomerular nephropathies. A statistically significant correlation (P <0.01) between cortical P, cortical P/T, medullary P, and serum creatinine and creatinine clearance was found. A significant correlation (P <0.01) was also found between cortical T, medullary P/T, T of the excretory system, and creatinine clearance. The cortical T value was significantly higher (P <0.01) in vascular nephropathy than in glomerular nephropathy. Thus in patients with chronic renal failure dynamic MRI shows both morphological and functional changes. Morphological changes are correlated with the degree of renal insufficiency and not with the type of nephropathy; the functional changes seem to differ in vascular from glomerular nephropathies.

A prospective randomised European multicentre study of medium-long run mortality and morbidity comparing acetate-free biofiltration and bicarbonate dialysis.

In recent years, the progressive increase in the mean age of the population entering chronic dialysis treatment has been responsible, on the one hand, for the growing number of patients undergoing regular dialysis, and on the other, for the high number of "critical" patients, both as a result of their age and the presence of concomitant morbidity. Thus, dialysis treatment today is not only aimed at waste removal and water-electrolyte homeostasis, but also at a reduction in morbidity and mortality, and at improving the patients' quality of life, thanks to the use of biocompatible materials and the achievement of good cardiovascular tolerance to treatment. Consequently, diffusive-convective dialysis procedures have been on the increase, since they combine better depuration with the use of biocompatible high-flux membranes. Acetate-free biofiltration (AFB) is a diffusive-convective dialysis procedure which utilises a high-flux membrane, AN69, post-dilution infusion of a sodium bicarbonate solution (NaHCO3), and a dialysate which is completely free of any buffer, and thus also free of acetate, which may have various negative effects on the patient. A number of studies have already shown the better hemodynamic stability and the reduction of intradialytic side-effects during AFB. All these, however, were short-term studies. To verify the beneficial effects of AFB in the long run, a three year multicentre randomised European trial has been proposed to compare bicarbonate hemodialysis (BD), a technique used in nearly 80% of the world's dialysis population, and AFB. The specific aim of the investigation is to verify, in a large number of patients, the results of hemodialysis treatment in terms of morbidity, mortality and quality of life. The study involves 80 hemodialysis units across Italy, France, Germany, Spain, Slovenia and Croatia, with enrollment of about 400 patients considered "critical" for at least one of the following reasons: age, diabetes, dialysis cardiovascular instability. Fifty percent of the patients are to undergo AFB with the AN69 membrane and bicarbonate solution infusion (NaHCO3 145 or 167 mEq/lt), and the other fifty percent are to be treated by BD, with any membrane except the nonmodified cellulosic one. Biochemical, cardiological, and nutritional parameters will be considered throughout the study. Mortality, morbidity both in terms of intra- and interdialysis symptoms - and hospitalisation rate, as well as the patients' quality of life, evaluated by the SF36 questionnaire, will be analysed.

Acetate free biofiltration (AFB): from theory to clinical results.

Acetate free biofiltration (AFB) is a hemodiafiltration technique based on a buffer-free dialysate and bicarbonate infusion in the postdilution mode. The performance of AFB requires a dialysis machine equipped with an automatic control system to balance the infusion rate to that of ultrafiltration. The filters employed are usually polyacrylonitrile hollow-fiber hemodialyzers. A 145 mEq/l sodium bicarbonate solution is generally used and the infusion rate is regulated at about 8-10 liters per session to ensure optimal convective removal of toxins as well as to compensate for the bicarbonate lost in the dialysate. During AFB bicarbonate transfer results from the balance between diffusive and convective bicarbonate losses in the dialyzer and the amount of bicarbonate infused in the venous return. Thus bicarbonate supply can increase along with the rise in plasma bicarbonate concentration until a steady state is reached when the rate of infused bicarbonate equals bicarbonate losses into the dialyzer. A mild alkalosis may sometimes occur which can be avoided by slightly reducing bicarbonate concentration and/or infusion rate during the session. In spite of the large amount of sodium infused and the unusual high chloride concentration in the dialysate, no difference in the postdialysis plasma sodium levels nor in chloremia has been observed between AFB and bicarbonate dialysis. This is essentially due to the very large removal of these anions by convection (chloride and sodium) and by diffusion (sodium) into the dialyzer. Similarly the significant convective losses of calcium suggest a high dialysate calcium concentration to avoid negative intradialytic calcium balance. Polyacrylonitrile membranes, regularly employed in AFB, allow the passage of endotoxin fragments to the blood circuit in a lesser extent than other membranes. Coupled with the fact that a buffer-free dialysate and a sterile bicarbonate infusion are used AFB can be considered a highly biocompatible dialysis technique. As compared to conventional dialysis AFB allows adequate removal of small molecules and better removal of larger molecules such as beta2-microglobulin. In the short run AFB is characterized by an increase in cardiovascular stability: it improves dialysis symptoms and the subjective well-being of patients. A better acid-base correction is regularly reported together with a rise in some nutritional indices like serum albumin levels. The reasons for these favorable results are not well defined yet. A number of multicenter studies on the effects of AFB have been published with quite similar results, but most of them are non-randomized, and use historical controls. Only one prospective, cross-over study comparing bicarbonate dialysis with AFB in diabetic dialysis patients is available. It concludes that in a six-month observation period with AFB it is possible to better control some metabolic aspects and to improve both treatment tolerance and patients' life quality. However, it is not known whether these positive effects may entail better long-term prognosis; moreover, comparisons between AFB and conventional dialysis were never designed to ascertain the role of the dialysis membrane from that of the other components of AFB on clinical results. Therefore, large prospective trials with long observation periods are necessary to clarify the mechanisms through which AFB might be superior to conventional dialysis as well as the impact of these techniques on long-term prognosis. In such studies other relevant factors such as rehabilitation and life quality of the patients, which have been generally neglected in previous surveys, must also be included to evaluate cost-effectiveness of this therapy.

Acetate-free biofiltration versus bicarbonate haemodialysis in the treatment of patients with diabetic nephropathy: a cross-over multicentric study.

BACKGROUND: Morbidity and mortality rates in diabetic patients on regular dialysis treatment (RDT) are higher than in non-diabetic-subjects on RDT. Moreover, diabetic patients experience an intradialitic morbidity unacceptably higher than in patients with other causes of terminal renal failure. The aim of the present investigation was to compare standard bicarbonate haemodialysis (BHD) with acetate-free biofiltration (AFB) in a group of 41 diabetic patients stable on dialysis treatment for 25 +/- 22 months. METHODS: Twenty-four type II and 17 type I diabetic patients, all requiring insulin therapy, were included and were followed for 1 year in a 6-month cross-over randomized study for both methods. The analysis was carried out on dialysis symptoms, interdialysis symptoms, and nutritional status, and the multivariate analysis of variance for repeated measures on the same subjects in the two techniques was used. RESULTS: AFB significantly reduced dialytic and extradialytic symptoms (P=0.003 and 0.001 respectively). Cardiovascular collapses decreased by 43%, and other dialysis symptoms showed a similar trend (-35%). The interdialysis symptoms decreased by 28% and were accompanied by an increase in subjective wellbeing (39%) when patients were switched from traditional haemodialysis to AFB. Acid base control was better with AFB (P=0.01), both at the beginning and during the session. Slightly significant differences were also obtained for Kt/V (AFB 1.48 +/- 0.29 vs BHD 1.38 +/- 0.30), while no significant difference was noted with respect to sodium mass balance, nutritional status, calorie-protein intake, nPCR, blood glucose profile, and insulin requirements. The number of hospital admissions and the mortality rate, which were much lower during the AFB than the BHD period, were not analysed statistically. CONCLUSIONS: AFB allows better control of some metabolic aspects, reduces intra- and extradialysis symptoms, and improves patient quality of life. Whether the long-term prognosis can be improved by AFB remains to be established with further studies.

Autonomic nervous function during haemodialysis assessed by spectral analysis of heart-rate variability.

1. Short-term autonomic response to haemodialysis-induced hypovolaemia was studied in 30 patients undergoing chronic haemodialysis by analysing power spectra of heart-period variability. Patients were classified as haemodynamically stable (15 patients) and unstable (15 patients) according to their past history of cardiovascular collapse during the treatment. Blood volume, systolic arterial pressure and heart period were measured during sessions that ended without the occurrence of collapse. 2. No significant differences were observed when comparing blood volume, heart rate and arterial pressure of stable and unstable patients during the dialysis, and the two groups could not be distinguished merely on the basis of these haemodynamic parameters. Conversely, spectral analysis of beat-to-beat heart-period variability showed markedly different power patterns: in stable patients power was mainly in the low-frequency (LF) band (0.06-0.15 Hz), whereas in unstable patients it was mainly in the high-frequency (HF) band (0.15-0.4 Hz). 3. The efficiency of the autonomic response to hypovolaemia was evaluated by the ratio between the powers in the LF and HF bands. Stable patients exhibited an LF/HF power ratio systematically greater than unstable patients during the entire dialysis, and on the basis of this index the two groups were clearly separated. 4. Results obtained with spectral analysis lead us to conclude that reduced efficiency in the autonomic control of cardiovascular functions could be the main cause of the haemodynamic instability of patients prone to collapse.

Echo color Doppler imaging of carotid vessels in hemodialysis patients: evidence of high levels of atherosclerotic lesions.

Cardiovascular disease is the major cause of death in patients with end-stage renal disease, and the incidence of atherosclerosis-related complications is significantly higher in dialysis patients than in nonuremic controls. This study aimed at evaluating atherosclerotic involvement of carotid vessels in hemodialysis patients and in a group of subjects with a similar cardiovascular risk factor pattern using echo color Doppler ultrasonography. Carotid lesions have been evaluated, taking into account plaque characters (surface, echogenicity), the most severe luminal narrowing, and the number of vessels involved. A large number of vascular plaques has been observed in uremic patients: 73.8% versus 44% in the control group (chi square test = 10.98; P < 0.01). A high prevalence of carotid lesions has been found in both patients and controls with clinical evidence of cardiovascular complications. Finally, we have considered the presence of carotid lesions with a topographic evaluation. The presence of atheromatous lesions in hemodialysis patients compared with control subjects was statistically significant different in all the vessels except common carotid (internal carotid: chi-square test = 8.59, P < 0.01; external carotid; chi-square test = 13.46, P < 0.01; bulb chi-square test = 7.90; P < 0.01). Our data clearly show that the hemodialysis population suffers from a higher degree of atherosclerosis than age- and sex-matched controls with similar cardiovascular risk patterns, suggesting that the uremic state in conservative and substitutive treatment per se may contribute to "advanced" atherosclerosis. However, this does not enable us to state that hemodialysis accelerates atherosclerosis. In fact, the progression of atherosclerosis might be related to atherogenic factors operative before regular dialysis.

Protein intake does not depend on the dose of dialysis delivered--provided Kt/V is adequate.

BACKGROUND: A link between malnutrition and the dialysis dose has been recently postulated on the basis of the direct relationship between Kt/V and nPCR and an increase in dialysis therapy has been also proposed in malnourished patients or when nPCR is less than 1 g/kg b.w., but the clinical meaning of such a relationship is unclear. DESIGN: Both dietary protein intake and nPCR were simultaneously determined in a selected population of 35 well-dialysed patients (Kt/V > 0.8) and were related to the delivered dialysis dose. RESULTS: No relationship was found between measured Kt/V (1.10 +/- 0.20) and dietary protein intake (PI, 0.98 +/- 0.20 g/kg) and similarly no relationship was evident between the dialysis dose and nPCR (0.99 +/- 0.20 g/kg). Although the mean nPCR value was similar to that of protein intake, nPCR exceeded protein intake when PI was less than 1 g/kg b.w. CONCLUSION: Our results demonstrate that if the dialysis dose is adequate, protein intake is a dialysis--independent or patient--dependent variable. They also show that at least 0.9 to 1.0 g protein per kg b.w are required to maintain nitrogen balance even in well-dialysed patients.

Autonomic nervous function and blood volume monitoring during hemodialysis.

We studied the autonomic reflex response to hypovolemia during HD by means of spectral analysis of heart rate variability (SAHRV) in 10 hypotension prone (group A) and 10 hemodynamically stable patients (group B). UF rate normalized per total body water and blood volume fall were similar in the two groups. The sympatho-vagal balance index, calculated as the ratio between the integrals of the spectrum in the low (0.02-0.15 Hz) and in the high frequency range (0.2-0.35 Hz) rose in group B progressively from the beginning of the treatments, reaching a top at the 90th minute and remained subsequently high until the end. On the contrary this index did not show remarkable increases in group A. The differences between the two groups were statistically significant at 0 (4.6 +/- 2.9 vs 1.5 +/- 1.3), 60th (8.3 +/- 7.8 vs 2.2 +/- 2.6), 90th (17.9 +/- 13.4 vs 3.7 +/- 2.8), 150th (8.8 +/- 3.7 vs 2.7 +/- 2.8) and 210th minute (8.6 +/- 5.0 vs 2.9 +/- 2.5). In conclusion SAHRV shows an impairment of autonomic reflex response to hypovolemia in hypotension-prone patients.