Effectiveness of various chemical disinfectants versus cleaning combined with heat disinfection on Pseudomonas biofilm in hemodialysis machines.

The development of bacterial biofilms in the hydraulic circuit of hemodialysis machines is routinely prevented by frequent use of a variety of chemical and heat disinfection strategies. This study compared the effectiveness of several chemical disinfectants, commonly used either alone or in combination with a treatment regimen that involved cleaning plus heat disinfection using an in vitro Pseudomonas biofilm model. Effectiveness of these procedures was evaluated using total and viable biomass quantitation and polysaccharide and endotoxin determination. The chemical disinfection procedures were only partially successful in removing all biofilm components. Heat disinfection alone killed viable biofilm bacteria, but did not remove all the biomass components, including endotoxin. The combination of cleaning with citric acid followed by heat disinfection was the most effective in eliminating all biofilm components from the hydraulic circuit of the in vitro model.

[Indications and preparations for kidney dialysis]. / Indication et préparation au traitement de suppléance rénale.

Every patient with end-stage renal failure, at any age and whatever the type of renal disease, is a legitimate candidate to maintenance dialysis. Contraindications are infrequent and based purely on medical considerations, such as profound and irremediable alteration of physical and/or mental condition. In patients regularly managed dialysis is decided electively on the basis of laboratory criteria in the absence of clinical uremic manifestations other than fatigue, anorexia or nausea. The most widely accepted criterion is a level of creatinine clearance estimated by the Cockcroft-Gault formula between 7 and 10 mL/min/1.73 m2. Psychological preparation of the patient to dialysis is essential and should not be delayed until the advanced stage. Medical preparation involves prophylactic vaccination against virus B hepatitis and creation of a native arteriovenous fistula when hemodialysis is the scheduled option. Every patient should receive in time clear and complete information on the various technical methods of dialysis, in order to allow him an informed choice.

Beneficial influence of recombinant human erythropoietin therapy on the rate of progression of chronic renal failure in predialysis patients.

BACKGROUND: Partial correction of anaemia with recombinant human erythropoietin (rHuEpo) has been shown to markedly improve the general condition and quality of life of predialysis patients, but the effects of rHuEpo therapy on blood pressure and the rate of progression of chronic renal failure (CRF) are still disputed. In particular, no study evaluated the time duration until the start of maintenance dialysis in treated patients, compared to untreated predialysis patients. METHODS: We retrospectively evaluated the rate of decline of creatinine clearance (Delta Ccr) and the duration of the predialysis period in 20 patients with advanced CRF treated with rHuEpo (Epo+ group), and in 43 patients with a similar degree of CRF but with less marked, asymptomatic anaemia, not requiring rHuEpo therapy (Epo- group). All patients were submitted to identical clinical and laboratory surveillance. All received similar oral supplementation with B(6), B(9), and B(12) vitamins and oral iron supplementation. Maintenance dose of subcutaneous epoetin was 54.3+/-16.5 U/kg/week (median dose 3300 U/week). RESULTS: Initial and final haemoglobin (Hb) levels were 8.8+/-0.7 and 11.3+/-0.9 g/dl in the Epo+ group, vs 10.9+/-1.2 and 9.5+/-0.9 g/dl in the Epo- group. In the Epo+ group, Delta Ccr declined from 0.36+/-0.16 during the preceding 24 months to 0.26+/-0.15 ml/min/ 1.73 m(2)/month after the start of rHuEpo therapy (P<0.05). No significant variation was observed in the Epo- group. Time duration until the start of dialysis was 16.2+/-11.9 in the Epo+ group, compared to 10.6+/-6.1 months in the Epo- group (P<0.01). Slowing of progression was observed in 10 Epo+ patients, whereas no significant variation in Delta Ccr occurred in the other 10. There was no difference in previous Delta Ccr rate, nor in Hb or blood pressure levels while on rHuEpo therapy between the two subgroups. CONCLUSIONS: Our study affords conclusive evidence that rHuEpo therapy did not result in accelerated progression of CRF in any treated predialysis patients, nor deleterious increase in blood pressure, but instead resulted in significant slowing of progression and substantial retardation of maintenance dialysis. Such encouraging results remain to be validated in a large prospective, randomized study.

Combined nutritional support and continuous extracorporeal removal therapy in the severe acute phase of maple syrup urine disease.

OBJECTIVE: The authors assessed the efficiency, tolerance and outcome of neonates and children with maple syrup urine disease (MSUD) in acute decompensation managed by endogenous and extracorporeal removal of accumulated MSUD metabolites. DESIGN: Single center cohort study. SETTING: Pediatric and neonatal intensive care unit in a tertiary care hospital. PATIENTS: Between January, 1991, and June, 1999, six neonates and six children in acute decompensation of MSUD were included in the study. Each of them had two of the three following criteria: comatose state, gastrointestinal intolerance, leucine plasma levels over 1700 micromol/l. INTERVENTIONS: Patients were treated by combined nutrition manipulation and continuous venovenous extracorporeal removal therapies (CECRT) including hemofiltration, hemodialysis or hemodiafiltration. A clinical and biological evaluation was performed before, during and following the treatment. RESULTS: Eleven out of the 12 patients survived. One child had two acute episodes at 6.5 and 9 years old. Eight patients recovered a normal cerebral performance category score. In all cases, plasma leucine level decreased according to a logarithmic mode within 11-24 h hemodiafiltration combined with nutritional support whereas, with nutrition alone after stopping CECRT, the decrease in leucine plasma levels was slower, following a linear mode. Eight patients were supplemented with valine and isoleucine for mean plasma values of 177+/-92 and 68+/-66, respectively. CONCLUSION: In severe acute decompensation of MSUD, CECRT combined with nutritional support limit central nervous system damage, by dramatically decreasing branched chain amino and keto acid levels.

Epidemiology of end-stage renal disease in the Ile-de-France area: a prospective study in 1998.

BACKGROUND: The objective of this study was to determine the incidence and prevalence of end-stage renal disease (ESRD) requiring maintenance dialysis in the Ile-de-France district (Paris area), and the characteristics of patients at start of dialysis. METHODS: This is a prospective epidemiological study with the cooperation of all dialysis facilities of the Ile-de-France district (population 10.7 million inhabitants as of March 1999). All consecutive ESRD patients who started dialysis from January 1 to December 31 1998, with demographic and clinical characteristics, and of the total number of patients on dialysis with their distribution according to dialysis modality were recorded. RESULTS: The total number of ESRD patients in 1998 was 1155, including 29 (2.5%) children aged < or =17 years and 86 (7.4%) returns to dialysis following kidney graft failure. Incidence of first-dialysed patients was 100 per million population (p.m.p.) and overall incidence, including returns from transplantation, was 108 p.m.p. The mean age of first-dialysed adult patients was 59.8+/-16.8 years, with 21.6% aged > or =75 years. Patients with vascular renal disease were 22.5% and those with diabetic nephropathy 20.6%. As a whole, 36.5% of patients were referred to the nephrologist < or =6 months before start of dialysis, including 32.2% referred < or =1 month before starting. Prevalence of cardiovascular disease was nearly twice as high in patients referred <6 months of starting dialysis than in those who benefited from effective nephrological care for >3 years in the predialysis period. By multivariate analysis, this difference persisted after adjustment for age and other confounding covariates. The total number of patients on maintenance dialysis increased from 417 to 433 p.m.p. (a yearly 3.8% increase) from the beginning to the end of 1998. CONCLUSION: This recent epidemiological study in a large French urban area indicates an annual incidence of 100 new ESRD patients p. m.p., with a high proportion of older, vascular and diabetic patients. Overall incidence, including returns from transplantation, reached 108 p.m.p. Cardiovascular disease was significantly less frequent in patients who received nephrological care for > or =3 years prior to start of dialysis than in late referred patients, underlining the benefits of early nephrological management of renal patients.

[Epidemiology of end-stage kidney failure in the Ile-de-France: a prospective cooperative study in 1998]. / Epidémiologie de l'insuffisance rénale terminale en Ile-de-France: enquête coopérative prospective en 1998.

A prospective epidemiological study was conducted from January 1 to December 31, 1998 in the Ile-de-France district to determine the incidence and the prevalence of end-stage renal disease (ESRD) and the characteristics of the patients. All nephrology and dialysis units of the Ile-de-France district participated in the study. The total number of ESRD patients requiring maintenance dialysis was 1155 (including 86 kidney graft failures and 29 children) for a total population of 10.7 millions inhabitants, or 108/10(6)/year. The incidence of new ESRD patients was 100/10(6)/year. The mean age of first-dialyzed, adult patients was 59.8 +/- 16.8 years, with 21.6% aged > or = 75 years. Vascular renal diseases accounted for 22.5% and diabetic nephropathy for 20.6%. As a whole, 36.5% of patients were referred to the nephrologist less than 6 months before starting dialysis. In the latter, the median duration of hospitalization was 28 days, compared to only 3 days in patients cared for by the nephrologist for at least 6 months. Prevalence of patients on maintenance dialysis in the Ile-de-France district grew from 417 to 433/10(6) from the beginning until the end of year 1998, an increment of 3.8%, with an increase in the number of patients treated out-center by self-care hemodialysis or peritoneal dialysis.

[Incidence of end-stage renal disease in Ile de France: a prospective epidemiological survey]. / Incidence de l'insuffisance rénale terminale en Ile de France: enquête épidémiologique prospective.

OBJECTIVES: To evaluate incidence and prevalence of patients with end-stage renal disease (ESRD) treated with maintenance dialysis in the Ile de France district in 1998. METHODOLOGY: Prospective epidemiologic inquiry with the cooperation of the 91 nephrology departments and dialysis facilities of the Ile de France district (total population: 10,695,300 inhabitants in March 1999), from January 1st to December 31st, 1998. Evaluation of the demographic and clinical characteristics of the 1155 patients accepted on maintenance dialysis in 1998, and recording of the total number of dialyzed patients at the beginning and at the end of the same year. RESULTS: The total number of ESRD patients was 1155, including 29 (2.5%) children aged < or = 17 years and 86 (7.4%) returns to dialysis following kidney graft failure. Incidence of ESRD in first-dialyzed patients was 100/million/year and overall incidence, including returns from transplantation, was 108/million/year. Mean age of the 1040 adult first-dialysis patients was 59 +/- 16.8 years, with a proportion of those aged > or = 75 years of 21.6%. Patients with vascular renal disease were 22.5% and those with diabetic nephropathy 20.6%. As a whole, 36.5% of patients were referred to the nephrologist < 6 months of starting dialysis. Prevalence of patients on supportive dialysis increased from 417 to 433 per million inhabitants (a 3.8% increase) from the beginning to the end of 1998, with the proportion of patients treated with self-care dialysis or peritoneal dialysis rising by 10%. From January 1995 to January 1999, prevalence of dialysis-treated ESRD patients rose by nearly 4% per year as a mean. CONCLUSION: Incidence of ESRD patients requiring maintenance dialysis in the Ile de France district reached 100/million in 1998, an increment of 4% per year over the past 4 years. The increase in incidence results from the increasing number of older patients, parallel to the ageing of general population, these patients having a high comorbidity mainly due to diabetes and atherosclerosis. Prevalence of dialysis-treated patients was 433/million population at the end of 1998. It rose at a similar rate as did incidence, although with a growing proportion of out-center dialysis.

Dyslipidaemia and the progression of renal disease in chronic renal failure patients.

BACKGROUND: Dyslipidaemia is common in patients with chronic renal failure (CRF), and there is increasing evidence to support the role of dyslipidaemia as a contributing factor in the progression of chronic renal disease. However, few prospective studies have been carried out which address the possible relationship between dyslipidaemia and the rate of progression of renal disease in patients with renal failure. METHODS: Between January 1985 and December 1997, we prospectively assessed the risk of CRF progression to dialysis in a cohort of 138 patients. Forty CRF patients reached end-stage renal disease (ESRD) and had to start supportive therapy during the follow-up period [group ESRD(+)]. The remaining 98 CRF patients served as controls [group ESRD(-)]. Potential clinical and laboratory risk factors for more rapid CRF decline to dialysis, including lipid abnormalities and baseline creatinine clearance were determined at the start of the follow-up period. RESULTS: Several significant differences were found in univariate analysis between the two groups of CRF, ESRD(+) and ESRD(-), namely a shorter follow-up period, a lower level of baseline creatinine clearance, a faster rate of creatinine clearance decline, a higher level of serum triglycerides, fibrinogen, total homocyst(e)ine and proteinuria, and a lower level of serum high-density lipoprotein in the ESRD(+) group than in the ESRD(-) group. However, by multivariate Cox analysis proteinuria [relative risk (95% confidence interval) 1.32 (1.16-1.50) for each g/day P = 0.001], baseline creatinine clearance [0.53 (0.40-0.70) for each 10 ml/min, P = 0.001] and chronic interstitial nephritis and hypertensive nephrosclerosis [0.38 (0.17-0.84) for presence, P = 0.005] were the only significant risk factors for CRF progression to dialysis. Hypertriglyceridaemia and male gender were selected in the final model, but were of borderline significance. CONCLUSIONS: These results suggest a limited role for dyslipidaemia in the progression of chronic renal disease to dialysis in CRF patients, in contrast with the powerful influence of proteinuria, baseline creatinine clearance and nephropathy type in predicting this progression.

Incidence of atherosclerotic arterial occlusive accidents in predialysis and dialysis patients: a multicentric study in the Ile de France district.

BACKGROUND: An abnormally high mortality from atherosclerotic cardiovascular (CV) accidents has long been reported in patients on maintenance haemodialysis (HD). However, incidence of atherosclerotic CV accidents had not been so far assessed in predialysis patients. In order to evaluate the respective influence of uraemia and the dialysis procedure, we compared incidence of atherosclerotic accidents before and after initiation of HD in a large population of patients. STUDY DESIGN: A total of 748 patients (411 male) were included in a retrospective study based on anamnestic data of patients living on maintenance haemodialysis in March 1993 in nine dialysis units of the Paris area. Incidence of first myocardial infarction (MI) or cerebral infarction (CI) was calculated by reference to the number of years of exposure to the risk both before and after initiation of HD in the various age groups. RESULTS: Overall, 103 first atherosclerotic accidents were recorded, including 10 CI (7 in males) and 93 MI (68 in males). Of the latter, 39 occurred before and 54 after start of HD, at a mean (+/-SD) age of 62.4+/-9.9 and 63.7+/-11.1 years respectively. The annual incidence of MI in males was 8.0, 19.5 and 28.3/1000 patient-years, before and 18.8, 21.6 and 29.9 patient-years after start of HD in the age groups 45-54.9, 55-64.9 and > or = 65 years respectively, compared to figures of 3.4, 7.5 and 10.4/1000 subject-years in the corresponding age groups in the general French population. CONCLUSION: Incidence of atherosclerotic CV accidents is nearly three times higher in uraemic patients than in the general population in the same age range in both genders. The fact that incidence and age at onset of first MI was similar in predialysis and in dialysed patients suggests that the uraemic state per se is a main determinant of such accelerated atherosclerosis.

Evidence of bacterial biofilm in tubing from hydraulic pathway of hemodialysis system.

Biofilms consist of microorganisms immobilized at a substratum surface embedded in an organic polymer matrix of bacterial origin. Tubing drawn from the fluid pathways within dialysis machines of various models were investigated for biofilm. Scanning electron microscopy (SEM), performed on approximately 2 cm2 samples of the tubing inner surfaces revealed that the inner surfaces of the tubing were covered with biofilms consisting of numerous deposits and glycocalix at different stages of formation with components containing bacteria and algae. Evaluations of biomass were performed from tubing sections of various lengths and inner diameters put in tubes containing water for injection and immersed in an ultrasound washtub for 1 h to ensure sloughing of the biofilm. Living bacteria were identified by plating on nutrient agar media and incubation for 48 h at 37 degrees C. Epifluorescent stains were used for the total bacteria count. Lipopolysaccharide levels were determined by the endotoxin activity measurements. Polyoside contents were determined by the colometric method, and the chemical oxygen demand was measured to evaluate the amount of organic substance. Biofilms detached from tubing samples drawn from the water path, bicarbonate path, and fresh dialysate path within dialysis machines contained approximately 1.10(3)-1.10(6) total bacteria/cm2, yet only some living bacteria were found. Endotoxin levels ranged from 1 to 12 EU/cm2. In contrast in the dialysate fluid, no bacteria were found, and the endotoxin content was under the detection level of the method. The polyoside content and chemical oxygen demand of the biomass ranged from 11 to 83 microg/cm2 and from 53 to 234 mg/cm2, respectively. It is concluded that a germ- and endotoxin-free dialysate does not exclude the risks and hazards of bacteria and endotoxin discharge from biofilm developed on the fluid pathway tubing, acting as a reservoir for continuous contamination, and efforts in the optimization of cleaning and disinfection procedures used for hemodialysis systems should aim to detach and neutralize biofilm when necessary.

Substitution of acetic acid for hydrochloric acid in the bicarbonate buffered dialysate.

In a multicenter study including 5 dialysis units, blood acetate changes during 4 h dialysis sessions in 141 patients treated with a 4 mM acetate-containing bicarbonate dialysate (ABD) were evaluated and compared to the values of 114 patients using an acetate-free bicarbonate dialysate (AFD). Acetate-free bicarbonate dialysate was delivered by a dialysis machine from the mixing with water for dialysis of a 1/26.2 bicarbonate concentrate, and a 1/35 acid-concentrate in which acetic acid was substituted for hydrochloric acid (Soludia, Fourquevaux, France). This new type of dialysate was routinely in use for 3 years on average (range, from 2 to 5 years). All patients fasted before and during dialysis. Blood samples were withdrawn at the start and at the end of dialysis sessions. The acetate plasma concentration was determined using the acetyl-CoA synthetase enzymatic method (Boehringer, Manheim, Germany). In patients treated with ABD whose predialysis blood acetate levels were in the physiologic range of < or = 100 microM (n = 113), the acetate plasma concentration increased from a predialysis mean value of 22+/-3 microM to a postdialysis mean value of 222+/-11 microM in 88 patients (78% of patients) whereas the acetate plasma concentration changes remained in the range of physiologic values from 21+/-6 to 58+/-7 microM in the other 25 patients. In contrast, patients treated with AFD whose predialysis blood acetate levels were in the physiologic range (n = 108), acetate plasma concentration increased from a predialysis mean value of 49+/-6 microM to 160+/-19 microM in only 13 patients (12% of patients) whereas acetate plasma concentration changes remained in the range of physiologic values of 23+/-2 to 41+/-3 microM in most of the patients of this group. In this study, a significant number of patients, whether receiving standard or acetate-free bicarbonate dialysates, exhibited an extremely high acetate plasma concentration at the start of the dialysis session. Hyperacetatemia was controlled with AFD in patients whose predialysis acetate plasma concentration of 316+/-82 decreased to 55 +/-23 microM (n = 6) at the end of the dialysis session whereas the acetate plasma concentration remained high when the predialysis concentration was 580+/-76 microM, with a postdialysis concentration of 233+/-39 microM (n = 28). It is concluded that in patients whose predialysis blood acetate levels were in the physiologic range, acetate-containing bicarbonate dialysate induces hyperacetatemia whereas postdialysis blood acetate remains in the normal range in such dialysis patients treated with acetate-free dialysate. Chronic hyperacetatemia, which could be found in dialysis patients, is well controlled by dialysis using an acetate-free dialysate.

Continuous venovenous hemodialysis in a neonate model: a two-pump system.

OBJECTIVE: To evaluate the efficiency and tolerance of venovenous hemofiltration, hemodiafiltration, and hemodialysis with a two-pump system in a neonatal animal model of acute renal failure. DESIGN: Prospective trial. SETTING: Animal laboratory at a large university-affiliated medical center. SUBJECTS: New Zealand white rabbits, weighing 3325 +/- 380 g. INTERVENTIONS: Venovenous hemofiltration, hemodiafiltration, and hemodialysis were performed in anesthetized rabbits with previous bilateral ureteral ligation. MEASUREMENTS AND MAIN RESULTS: At a blood flow rate of 19 +/- 0.5 mL/min, we determined hematocrit, urea, creatinine, and electrolyte values in blood, at the inlet and outlet of the hemofilter, and in ultrafiltrate at the start and after 15, 30, 60, 90, 120, and 180 mins of hemofiltration (ultrafiltrate flow rate of 1.9 +/- 0.2 mL/min), hemodiafiltration (dialysate plus ultrafiltrate flow rate of 16.9 +/- 0.8 mL/min), and hemodialysis (dialysate flow rate of 15.7 +/- 1.1 mL/min). Arterial blood pressure, heart rate, and body temperature were monitored during the procedures. Urea and creatinine instantaneous clearances were higher with hemodiafiltration (8.0 +/- 0.7 and 6.2 +/- 0.7, respectively, n = 29) and hemodialysis (6.8 +/- 1.1 and 4.8 +/- 0.9, respectively, n = 31) than with hemofiltration (1.8 +/- 0.6 and 1.9 +/- 0.4, respectively, n = 16). Initial and final weights, temperatures, and hematocrit, sodium, and protein blood concentrations of each 180-min procedure were similar. CONCLUSIONS: Hemodiafiltration had a higher urea removal rate than hemodialysis but the management of hemodiafiltration was more cumbersome and time consuming in the absence of a flow equalizer device. As a result, we recommend continuous venovenous hemodialysis as the therapy of choice.

[Incidence of atherosclerotic cardiovascular events in patients with chronic uremia: epidemiologic studies in Ile-de-France]. / Incidence des accidents cardio-vasculaires d'origine athéromateuse chez l'urémique chronique: études épidémiologiques en Ile-de-France.

An abnormally high mortality from atherosclerotic cardiovascular (CV) accidents has long been reported in patients on maintenance hemodialysis (HD). However, incidence of such complications had not been so far evaluated in chronic renal failure (CRF) patients not yet on dialysis. In a cohort study bearing on 232 predialysis CRF patients, followed as out-patients at Necker hospital, incidence of first myocardial infarction (MI) was three times higher than in the French general population in every age group and in both genders, with a mean (+/- SEM) age at onset of MI of 62.9 +/- 1.2 years. In a retrospective cooperative study involving 748 patients treated in 9 hemodialysis centers in the Ile-de-France area, incidence of first MI episodes did not differ before and after start of HD therapy and was similar to that observed in the cohort study. Mean age of patients at first MI, before and after start of HD, was respectively 62.4 +/- 1.6 and 63.7 +/- 1.5 years, a not significant difference. In conclusion, two epidemiologic studies confirm the existence of accelerated atherosclerosis in CRF patients, the incidence of MI being 3 times higher in uremic patients than in the general population in every age group and in both genders. The fact that incidence of first MI episodes and age at onset was similar in predialysis and in dialyzed patients suggests that the uremic state per se is a main determinant of such accelerated atherosclerosis. It results that therapeutic measures aimed at preventing development of atherosclerosis should be initiated from the early stage of CRF, long before start of renal replacement therapy.

[Benefits of early nephrological management in chronic renal failure]. / Bénéfices d'une prise en charge néphrologique précoce de l'insuffisance rénale chronique.

OBJECTIVES: We evaluated whether early nephrological referral of patients with chronic renal failure (CRF) resulted in improved condition of patients at initiation of maintenance dialysis and in better outcome on dialysis. PATIENTS AND METHODS: We prospectively recorded clinical status, laboratory parameters, length of hospital stay and outcome of 900 CRF patients who started maintenance dialysis at Necker hospital between January 1989 and December 1996. We compared patients who benefited regular nephrological follow-up, and patients who were referred in emergency conditions at the ultimate stage of CRF. RESULTS: Among the 900 patients, 731 (81.2%) had regular nephrological follow-up, including 632 (70.2%, group IA) with optimal preparation to dialysis and 99 (11%, group IB) whose clinical course was complicated due to heavy comorbidity, whereas 169 (18.8%, group II) had no previous nephrological management. Over the 8-year observation period, the proportion of the latter group did not decrease. Late referred patients had higher blood pressure level, more frequent fluid overload, higher serum levels of urea, creatinine, uric acid and phosphate, and lower levels of bicarbonate, calcium, albumin and creatinine clearance that did well-prepared patients. Mean (+/- SD) hospital stay was 29.7 +/- 15.8 days in the former compared to only 4.8 +/- 3.3 days (p < 0.001) in the latter. Early deaths within 3 months of dialysis initiation were more frequent (7.1 vs 1.6%, p < 0.05) and less patients subsequently were able to be treated out-center (20.1 vs 40.7%, p < 0.05) in group II than in group IA. The overcost induced by late referral may be estimated at 0.25 million French francs per patient. CONCLUSION: An unjustified late nephrological referral of CRF patients still is observed in nearly 20% of cases. Such late referral is detrimental to both patients in terms of altered quality of life and long hospital stay, and to the collectivity due to heavy overcost. Closer cooperation between family physicians and nephrologists is needed to provide optimal management and allow timely preparation to maintenance dialysis of CRF patients.

Continuous venovenous haemodiafiltration in the acute phase of neonatal maple syrup urine disease.

Maple syrup urine disease results in accumulation of leucine and its metabolites, which may lead in the long term to neurological dysfunction. In acute neonatal crises, large amounts of leucine may be removed by continuous venovenous haemofiltration. This extracorporeal technique has its risks and hazards, which increase with duration of treatment. We report three neonates in life-threatening conditions due to maple syrup urine disease, treated for not more than 12 h with various continuous venovenous techniques: continuous haemofiltration, haemodiafiltration and haemodialysis. The efficiency of and tolerance to these techniques was evaluated. For all three patients, plasma leucine levels decreased dramatically from 2186, 3818 and 2536 mumol/L to 1131, 1275 and 488 mumol/L, respectively. Leucine clearance obtained was 4.28 ml/min in haemodiafiltration. Their patients' neurological status improved rapidly and they have a normal developmental quotient at 22 months, 13 months, and 11 months of age, respectively. Tolerance was good except for hypothermia and drop in haematocrit in all cases. Haemodiafiltration management was more cumbersome and time consuming because it required continual adjustment of the substitution fluid flow rate to precisely balance inflow and outflow rates. We recommend continuous venovenous haemodialysis as the therapy of choice. It might be anticipated that improvement of this technique, by increasing dialysate flow rate and blood flow rate, will allow leucine concentration to be decreased below 1000 mumol/L within 6-8 h, whatever the initial level.

[Benefits of early nephrological management of chronic renal failure]. / Bénéfices d'une prise en charge néphrologique précoce de l'insuffisance rénale chronique.

OBJECTIVES: We evaluated whether early nephrological referral of patients with chronic renal failure (CRF) resulted in improved condition of patients at initiation of maintenance dialysis and in better outcome on dialysis. PATIENTS AND METHODS: We prospectively recorded clinical status, laboratory parameters, length of hospital stay and outcome of 900 CRF patients who started maintenance dialysis at Necker hospital between January 1989 and December 1996. We compared patients who benefited regular nephrological follow-up, and patients who were referred in emergency conditions at the ultimate stage of CRF. RESULTS: Among the 900 patients, 731 (81.2%) had regular nephrological follow-up, including 632 (70.2%, group IA) with optimal preparation to dialysis and 99 (11%, group IB) whose clinical course was complicated due to heavy comorbidity, whereas 169 (18.8%, group II) had no previous nephrological management. Over the 8-year observation period, the proportion of the latter group did not decrease. Late referred patients had higher blood pressure level, more frequent fluid overload, higher serum levels of urea, creatinine, uric acid and phosphate, and lower levels of bicarbonate, calcium, albumin and creatinine clearance that did well-prepared patients. Mean (+/- SD) hospital stay was 29.7 +/- 15.8 days in the former compared to only 4.8 +/- 3.3 days (p < 0.001) in the latter. Early deaths within 3 months of dialysis initiation were more frequent (7.1 vs 1.6% p < 0.05) and less patients subsequently were able to be treated out-center (20.1 vs 40.7%, p < 0.05) in group II than in group IA. The overcost induced by late referral may be estimated at 0.25 million French francs per patient. CONCLUSION: An unjustified late nephrological referral of CRF patients still is observed in nearly 20% of cases. Such late referral is detrimental to both patients in terms of altered quality of life and long hospital stay, and to the collectivity due to heavy overcost. Closer cooperation between family physicians and nephrologists is needed to provide optimal management and allow timely preparation to maintenance dialysis of CRF patients.

Incidence and risk factors of atherosclerotic cardiovascular accidents in predialysis chronic renal failure patients: a prospective study.

BACKGROUND: Accelerated atherosclerosis resulting in an abnormally high incidence of coronary and cerebrovascular occlusive accidents has been repeatedly reported in dialysis patients, but incidence and risk factors of such complications in chronic renal failure (CRF) predialysis patients are debated. METHODS: We prospectively assessed the incidence of first myocardial and cerebral infarction episodes in a cohort of 147 CRF patients (99 male) followed from January 1985 to December 1994. Relevant clinical and laboratory risk factors for atherogenesis were determined at yearly intervals. They included blood pressure, smoking, blood lipids, fibrinogen, and homocysteine which were compared in patients with (CVA+) or without (CVA-) occurrence of cardiovascular (CV) atherosclerotic accidents. RESULTS: Incidence of CV accidents was nearly three times higher in CRF patients than in the French general population in both genders. In particular, incidence of myocardial infarction in male patients aged 45-55, 55-65 and > 65 years was 7.6, 18.2, and 27.8/1000 patient-years, respectively, compared to 3.4, 8.9, and 10.4/1000 subject-years in the general population. Although age and degree of renal failure at onset of CV events or at end of follow-up did not differ between CVA+ and CVA- groups, cigarette smoking (24.5 [SD 24.3] vs 8.2 [14.7] pack-years, P < 0.0001) and systolic blood pressure (159 [19] vs 148 [19] mmHg, P < 0.001) were markedly higher in CVA+ patients. Similarly, mean plasma HDL-cholesterol was lower, whereas LDL-cholesterol, triglycerides, apoB, Lp(a), fibrinogen, and homocysteine levels all were significantly higher in CVA+ than in CVA- patients. Multivariate Cox analysis identified cigarette smoking, systolic pressure, HDL cholesterol, and fibrinogen as independent risk factors for developing CV accidents. CONCLUSIONS: Incidence of atherosclerotic CV complications is abnormally high in predialysis CRF patients, suggesting that the uraemic state per se is associated with atherogenesis. As several of the identified clinical and metabolic risk factors for such accidents are potentially remediable by specific therapeutic interventions, prophylactic measures should be initiated long before start of renal replacement therapy.

Blood density monitoring during dialysis.

Continuous monitoring of blood density (BD) was preformed in 4 stable dialysis patients in 20 sessions using a density meter based on a mechanical oscillator technique. Mean predialysis and postdialysis BDs were 1.0427 +/- 0.0031 g/cm3 and 1.0502 +/- 0.0055 g/cm3, respectively. For similar predialysis to postdialysis total body water reduction, significant difference in the mean BD increase was found between hypotensive and nonhypotensive groups (1.29 +/- 0.07%, 0.47 +/- 0.12%, respectively; p < 0.001). Eight hypotensive episodes occurred during 6 sessions. The mean value of the blood density changes slope (dBD/dr) during the 5 min preceding a hypotensive episode increased about 2.5 times more than did the mean of the predialysis to postdialysis blood density slope (27.6 +/- 2.2 g/cm3.min.10(-5), 10.5 +/- 0.4 g/cm3.min.10(-5), respectively; p < 0.001) under the condition of a constant ultrafiltration rate of 18.9 +/- 0.6 ml/min. Continuous monitoring of blood density allows abrupt change in plasma volume to be identified and seems to have a potential utility to the prevention of symptomatic hypotension episodes in patients receiving hemodialysis.

Age and gender-related incidence of chronic renal failure in a French urban area: a prospective epidemiologic study.

OBJECTIVE: To determine the age- and gender-related incidence of chronic renal failure in a French urban area. METHODS: Prospective study of adult patients newly identified as having established, chronic renal failure defined by serum creatinine (Scr) > or = 200 mumol/l, with the cooperation of all nephrology and dialysis units in the Ile de France district (10,660,000 inhabitants) during a 1-year period. RESULTS: 2775 patients (1780 males, 995 females) were referred with Scr > or = 200 mumol/l between July 1991 and June 1992, an overall incidence of 260/million population. 847 had advanced renal failure (Scr > or = 500 mumol/l) and 541 patients (19.5%) were > or = 75 years of age. The age-related incidence was 92, 264, 523 and 619/million population in the age groups 20-39, 40-59, 60-74 and > or = 75 years old, respectively. The annual incidence was twice as high in males than in females up to 75 years and three times as high in patients > or = 75 years (1124 vs 356/million population). Based on the proportion of patients reaching end-stage renal failure within one year of referral, the minimal estimation of the need for supportive therapy is 81/million/year. CONCLUSIONS: This epidemiological study in a large French urban area indicates an incidence of 260 patients per million population annually referred to nephrology units for chronic renal failure defined by Scr > or = 200 mumol/l, with a marked preponderance of males and a dramatic increase of incidence with age in both genders.