[Scabies in a dalysis unit. Mystery and prejudice]. / La scabbia in un centro dialisi. Mistero e pregiudizio.

BACKGROUND: Pruritus is one of the most common symptoms of uremia. The etiology of uremic pruritus is steel incompletely known. Scabies may be a cause of itching in these patients. METHODS: Retrospective analysis of beginning and developing of a scabies outbreak in a Dialysis Unit with 160 patients. RESULTS: Sixteen cases of scabies were observed in the Dialysis Unit from April 1998 and January 1999: in 6 of them the scarification was positive. In 10 the scarification was negative, but itching disappeared after treatment with benzyl benzoate 20%. Many courses were necessary (max 6). Prophylaxis (treatment with benzyl benzoate 20% for 3 days and lingery cleaning) was applied to approximately 400 people. No cases were observed among health care workers of the Dialysis Unit. CONCLUSIONS: In a Dialysis Unit the diagnosis of scabies is difficult because the patients often have generalized itching; moreover some of them are affected by neuropathy that may make the infestation of scabies more difficult to identify. The most important factor to limitate the outbreak seems to be the prophylaxis of people who take care of patients (health-care workers, family members and car-drivers). It seems also necessary to repeat the treatments many times. The most exposed patients seemed to be those with diminished independence, diabetes and malnutrition.

[Acute renal failure. Epidemiologic observations in the Piedmont region]. / Insufficienza renale acuta. Osservazioni epidemiologiche nella Regione Piemonte.

BACKGROUND: The use of ICD9-CM for the classification of disease has been introduced in Italy. A retrospective study has been performed to evaluate the incidence of Acute Renal Failure Dialysis treated (ARFD) in Piedmont (4,500,000 inhabitants) and to evaluate the use of ICD9-CM for the classification of Acute Renal Failure (ARF) in the compilation of Hospital Discharge Sheets (SDOs). METHODS: The Piedmont Renal Transplant Registry was used to look for episodes of ARFD in the Region in 1997. All cases of ARF (584,5,6,7,8,9- 997.5- 958.5- 788.9- 634.3-639,3-669.3) were looked for in SDOs of all admissions to hospitals in the Region in the same period. RESULTS: 646 episodes of ARFD were found in the Piedmont Registry, that is an incidence of 142 episodes/million/year. 830 episodes of ARF (184 episodes/million/year) were found in an analysis of SDOs. It is impossible to find cases of ARFD from an analysis of SDO data. CONCLUSIONS: The ICD9-CM system, in Piedmont, in 1997, wasn't well utilized and the data are not useful for epidemiological studies unless further education in their use has been carried out. The analysis of the Piedmont Registry evidences that in the Region all the cases of advanced ARF (creatinine > 5 mg%) are treated by Dialysis. This may indicate a good performance of nephrological care, but the data have to be confirmed, because the incidence of ARFD is higher than in other European countries.

GIT (Glucose Infusion Test): polycentric evaluation of a new test for vascular access recirculation.

Introduction. Vascular access recirculation (AR), which is often unacknowledged, remains an important cause of inadequate dialytic dose. The glucose infusion test (GIT) is a new method for detecting and quantifying AR. This paper reports on a polycentric evaluation of the new test and a comparison with the classical Urea-test (UT). Methods. GIT protocol comprises withdrawal from the arterial port (sample A), injection into the venous drip chamber of 1 g glucose in 4 seconds, withdrawal from the arterial port (sample B) continuously from 13 to 17 seconds. Glucose is determined on A and B by a reflectance photometer. If B = A then there is no recirculation. If B exceeds A by at least 20 mg/dl there is recirculation. AR quantification: AR% = (B-A) / 20. GIT was performed on 623 patients from eleven dialysis centers to screen the patients for AR. Subsequently, GIT and Urea-test (UT) were compared in 189 paired tests. The reproducibility of GIT and UT was studied in 28 paired tests performed in sequence. Results. The screening test by GIT was positive in 68 cases (11 %). The majority of positivities was found in central venous catheters (CVC, 27/50 cases, 54 %), whereas only 7 % of artero-venous fistulas (AVF) were positive. In the CVC group, Tesio catheters were more frequently positive compared to Dual Lumen Catheters (64 % vs. 29 %). The comparison GIT - UT showed that results matched in 162 tests (79 negative and 83 positive both by GIT and UT), showing that on the grounds of UT, GIT has high sensitivity and specificity. In 27 tests GIT was positive, but UT negative. This disagreement is due to the different minimal limit of detection, 1 % for GIT and 5% for UT. The reproducibility was greater with GIT than with UT with a lower D% (respectively -0.6 +/- 2.5 and -0.4 +/- 6.1 %, p<0.001) and a lower coefficient of variation (17 vs 33 %). Conclusions. The screening of 623 patients by GIT confirmed that AR in AVF is normally absent, whereas an un-expectedly high frequency of moderate AR in CVC was found. The GIT-UT comparison showed that the new test is simple and immediate, and gives results with higher accuracy, sensitivity and reproducibility than UT.

[Immune response to influenza vaccination among peritoneal dialysis patients]. / Risposta immune alla vaccinazione antiinfluenzale nei pazienti in dialisi peritoneale.

The influenza vaccination is considered useful in preventing influenza and its complications, but its efficacy is variable especially in uremia. The humoral efficacy in a group of 15 patients in peritoneal dialysis treatment has been evaluated. Antibody responses were measured before vaccination and at time intervals of 1-4 months after vaccination. A good response to viruses A (A/H3N2/Johannesburg 33/94, A/H1N1/Singapore 6/86), respectively 80% and 66.7% and an attenuated response (20%) to virus B (B/Beijing 184/93) was observed. For viruses A, the "non responders" were elder patients with a low count of lymphocytes. For virus B it is suggested that the low response is perhaps related to variable effectiveness of vaccine.

Effect of on-line conductivity plasma ultrafiltrate kinetic modeling on cardiovascular stability of hemodialysis patients.

The aim of this multicenter, prospective, randomized cross-over study was to clarify whether on-line conductivity ultrafiltrate kinetic modeling (treatment B), as a substitute for sodium kinetic modeling, is capable of reducing intradialytic cardiovascular instability in comparison with standard treatment (treatment A), by reducing the sodium balance variability. Both treatments were performed by means of a modified hemodiafiltration technique. Treatment A was performed using fixed dialysate conductivity; treatment B made use of the dialysate conductivity derived from a conductivity kinetic model, in order to obtain an end-dialysis ultrafiltrate conductivity at each dialysis session that was equal to the mean value determined in the same patient during the four-week run-in period. Thus, during treatment B, the expected end-dialysis ultrafiltrate conductivity value of each patient should have been constant. The study was carried out according to a multicenter cross-over design of 16 weeks with two treatments (A or B), two sequences (1 = ABB and 2 = BAA), a run-in period of four weeks (period 1, treatment A), and three consecutive experimental periods of four weeks each. Analysis of variance for a cross-over design was used for the statistical analysis. Forty-nine hemodialysis patients prone to intradialytic hypotension (> 25% of sessions) were enrolled from 16 participating centers, and randomly assigned to either sequence 1 (26 patients) or sequence 2 (23 patients). Six patients dropped out and four were protocol violators, which left 39 patients selected for statistical analysis. There was no difference in the average dialysate conductivity, predialysis and end-dialysis plasma water ultrafiltrate conductivity or body weight between treatment A and treatment B. Thus, the observed mean sodium balance was not different and, as expected, only the intra-patient variability of end-dialysis ultrafiltrate conductivity (index of sodium balance variability) was reduced (21%). During treatment A, systolic blood pressure decreased by 23 mm Hg (95% confidence intervals 21 to 24 mm Hg) at the end of dialysis with respect to the pre-dialysis values. Treatment B reduced this intradialytic decrease (P = 0.001) with a maximum effect at the third hour of dialysis (4.4 mm Hg, 95% confidence intervals 1.9 to 6.9 mm Hg, 23% less than during treatment A, P 0.0005) without any period or carry-over effect (P = 0.53 and 0.08, respectively). There was no treatment effect on intradialytic diastolic blood pressure (P = 0.291). In conclusion, intradialytic cardiovascular stability was significantly improved by matching the interdialytic sodium load with intradialytic sodium removal using on-line conductivity ultrafiltrate kinetic modeling as an alternative to sodium kinetic modeling. Although highly significant, this effect was clinically not very large. By applying this conductivity kinetic model to patients with a more variable sodium intake from one session to another, a greater benefit can be expected.

[Effectiveness of influenza vaccination in patients undergoing regular dialysis treatments]. / Efficacia della vaccinazione antifluenzale nei pazienti in trattamento dialitico regolare.

BACKGROUND: The influenza vaccination is considered useful in preventing influenza and its complications, but its efficacy is variable. Recent data on clinical effectiveness of influenza vaccination in renal patients are lacking. MATERIALS AND METHODS: The clinical efficacy in our Hemodialysis Unit during the last three years has been evaluated: 287 patients have been vaccinated. The rate of vaccination achieved has been of 81.3%. RESULTS: The efficacy has been of 46.7%. The difference of efficacy noted among young people (< 60 years) and elderly (> 60 years) in general population is not observed among our hemodialyzed patients. Bronchopulmonary complications (radiographically proven) have been low: 1.7%. No mortality increase has been observed. CONCLUSIONS: These findings suggest that influenza vaccine can reduce the incidence and severity of influenza virus infections also among hemodialyzed patients.

Optimizing sodium balance in hemodialysis.

this paper develops and tests a mathematical model for Na+ kinetics applied to standard hemodialysis. The volume of distribution of exchangeable Na+, dialyzer surface area, blood and dialysis fluid flow rate, target weight loss, treatment duration and the Na+ diffusibility constant are taken into account. The model is used to compute the optimal hour by hour dialysis fluid Na+ concentration required to achieve the prescribed end-dialysis natremia and maintain a constant end-dialysis body Na+ pool, while providing a nearly uniform removal of Na+ over dialysis. The model was preliminary tested on 10 consecutive dialyses in a single patient using special dialyzer which generates a part of ultrafiltrate uncontaminated by dialysate.

Are serum albumin and cholesterol reliable outcome markers in elderly dialysis patients?

Albumin and cholesterol are considered reliable outcome markers in dialysis patients; their influence, however, may also be related to non-independent factors, such as age and presence of co-morbid conditions. The aim of the study was an analysis of four outcome markers, assessed at start of dialysis: age, high risk conditions, cholesterol and albumin levels. Data were obtained from the Piedmont Dialysis and Transplantation Registry (northern Italy, about 4,400,000 inhabitants, 21 dialysis centres, open acceptance since mid-1970s, 5661 patients on file at 31 December 1992). Prevalence of albumin and cholesterol in the normal range increases with age; in each age group prevalence in the range is higher in patients at high risk. However, influence of these biochemical parameters is evident also in no-risk cohorts, thus identifying a subgroup with poorer prognosis also in the population without any identified classic risk factor. The influence of albumin, more evident in the population studied compared with cholesterol, is reflected by impaired survival of low-albumin patients (age > or = 65 high risk at 1 year: 60.7% vs 76.6%, P = 0.0052; age > or = 65 non-high risk, at 1 year: 76.5% vs 90.7%, P = 0.0001). In conclusion, albumin and cholesterol, assessed at start of dialysis, are reliable outcome markers even in elderly patients, identifying, in this high mortality cohort, a subgroup with poorer prognosis. If and how their effect may be reversed by dialysis therapy remains to be assessed.

[Evolution of the serum aluminum values in the Piedmont dialysis population. Dialysis Centers of the Piedmont]. / Evoluzione dei valori di alluminio serico nella popolazione dialitica piemontese. Centri Dialisi del Piemonte.

The authors have evaluated the evolution of values of serum aluminium concentration (Als) in the whole pool of patients undergoing RDT in Piedmont in the years 1982-1990. We have compared the data of the Piedmont Regional Registry of Dialysis and Transplantation at the end of 1990 to those obtained in 1982, 1986 and 1989. A progressive reduction has been observed in the percentage of patients with Als > 100 micrograms/l, who were 13.5% of the pool in 1982 and 7.5% in 1986 and finally decreased to 1.5% in 1990. This is yet more evident for patients dialyzing at home as in 1982 43% of them had a Als > 100 micrograms/l, whereas in 1986 only 8.2% did and in 1990 this percentage had decreased to 3.6%. The values of Als (distinguished by type of treatment of chronic renal failure) show end confirm the improvement of the situation of aluminium accumulation, specially as regards bicarbonate HD where the percentage of patients with Als > 100 micrograms/l decreases from 10.5% in 1986 to 1.7% in 1990. These data point out the efficacy of prevention and control programs regarding aluminium pathology performed in the last years in Piedmont. This has led to a reduction of the severe accumulation syndromes observed in the first years of '80 and has allowed the nephrologist to prepare more correct therapeutic prescriptions.

Production of tumor necrosis factor-alpha in patients on hemodiafiltration.

The systemic production of tumor necrosis factor (TNF)-alpha was evaluated in uremic patients before and after hemodiafiltration (HDF) and paired filtration dialysis (PFD) and in the interdialytic period. Both HDF and PFD were performed using polysulfone dialyzers with either standard or ultrapure dialysis fluid. TNF-alpha was quantitated by using a specific biological assay based on its cytotoxic effect on a TNF-sensitive human melanoma cell line SK-MEL-109. Postdialytic mean plasma TNF-alpha levels decreased, albeit not significantly, in regard to predialytic values. These results differ from those obtained in patients on HDF using other high-permeability membranes such as polymethylmethacrylate and polyacrylonitrile (AN 69) as recently described by us. Of interest, the adoption of ultrapure dialysis fluid resulted in a marked reduction in the interdialytic production of TNF-alpha. These results suggest that the enhanced production of TNF-alpha in patients dialyzed with high-permeability membranes is mainly dependent upon the bacteriological purity of dialysis fluid.

[Role of tumor necrosis factor in hemodiafiltration]. / Ruolo del tumor necrosis factor in emodiafiltrazione.

The Authors review the mechanisms involved in the production of cytokines during substitutive extracorporeal treatment with particular reference to microbial contamination and possibility of backfiltration of bacterial constituents more likely to occur with high permeability membranes. Recent and on-going studies from our laboratory support the contention that patients treated with high permeability membranes may be chronically stimulated. Use of "ultrapure" solution indeed brings about a marked reduction in predialytic plasma levels of tumor necrosis factor (TNF) in regard to what observed when standard solutions are adopted.

[Role of paired filtration dialysis in substitutive treatment]. / Ruolo della paired filtration dialysis nel trattamento sostitutivo.

The Authors have evaluated the possibilities of use of the PFD in the regular dialysis treatment. At first they have studied in 8 patients the advantages offered by this technique in terms of depuration of small molecules and of tolerance in comparison with HD and HDF. Subsequently, they have compared the performances obtained in HF in a second group of 7 patients with the results observed in PFD executed by using 2 dialyzers on line and, in a second phase, in parallel, extending the comparison parameters to a higher molecular weight solute such as the beta 2-M. The results obtained indicate the PFD as a technique which can offer (compared to HD) a better tolerance and higher depurative performances, which on their turn can eventually allow a reduction of the length of the treatment. Moreover the possibility of executing the PFD with 2 polysulfone dialyzers on line and in parallel, increasing the UF to 13.5 and 15 L, renders this technique competitive with the HF also for its capacity of removing the beta 2-M.

[Neurotoxic action of muzolimine at high doses in uremic patients. Observation of a group of 29 subjects]. / Azione neurotossica della muzolimina ad alte dosi in pazienti uremici. Osservazione su un gruppo di 29 soggetti.

We report the results of a study on 29 patients affected by renal chronic insufficiency and treated with high doses of muzolimine. From our data it results that to the muzolimine is probable due a neurological syndrome very similar to combined sclerosis. Up today, it is not possible to know how and where the muzolimine develops its neurotoxic effect.

Three-year follow-up after withdrawal of iron therapy in uremic patients on regular dialytic treatment.

Iron supplementation is commonly recommended in uremic patients undergoing regular dialytic treatment in order to correct a presumed iron deficiency due to impaired absorption and dialytic losses. Serum ferritin levels show an iron overload in 83% of 136 patients on 1.25 g/year i.v. iron therapy. After the withdrawal of iron therapy, directly correlated ferritin levels and percentage transferrin saturation decreased slowly, except in carriers of HLA-A3 antigens and in polytransfused patients. In these latter patients, desferrioxamine reduced but did not normalize the iron balance. The 16 patients who never received iron therapy showed a normal iron balance over a 3-year follow-up. Despite iron-ferritin therapy, 11 patients with baseline ferritin values at the lower normal limits showed a tendency toward further depletion. Orally administered bivalent iron seems to be more promising in normalizing iron-deficient patients without potentially harmful overloading.

[Renal tolerance for aminoglycosides]. / Tollerabilità renale agli aminoglicosidi.

Tissue pharmakinetics, morphology of renal lesions and clinical picture of aminoglycoside-induced tubulopathy are described. Almost completely filtered by the glomerulus, they are eliminated in active form and about a third are reabsorbed along the proximal convoluted tubule, thus reaching maximum concentration in the renal cortex in the sixth hour as the drug disappears from the circulation. They are located inside the lysosomes of the convoluted tubule cells where some typical formations called myeloid bodies are present. Cellular lesions are, however, only produced by high doses after, first, clinical manifestations of tubular disturbance such as polyuria, tubular proteinuria, enzymuria, followed, if the toxic insult persists, by renal insufficiency. This can present clinically as progressive renal function deterioration dependent on the dose-time factor. This deterioration is usually not oliguric and it may also present as a sudden oliguric renal insufficiency. The now fully documented risk factors are discussed as well as the duration of treatment (not more than 11 days), the dosage (3 mg/kg/die), the dosage intervals, the age factor (the elderly being shown to be more highly sensitive to the drug), the association with other aminoglycosides or diuretics or cephalosporin. It is very important to diagnose already existing nephropathies or renal insufficiency, in which case dosages must be appropriately reduced. The nephrological history of the patient and control of urea and creatinine clearances before the start of treatment (in addition, obviously, to functional control of the eighth pair of cranial nerves) are essential for all patients receiving courses of aminoglycoside therapy. It is also necessary to check renal function by daily measurements of creatinaemia and urine. These precautions are valid for all aminoglycosides including those that have come on to the market most recently.