Electrolyte concentration during haemodialysis and QT interval prolongation in uraemic patients.

AIMS: To assess the effect of different combinations of potassium and calcium concentrations on QT interval in the dialysis bath in uraemic patients. METHODS AND RESULTS: Sixteen haemodialysis (HD) patients underwent a 24 h Holter recording before and during HD sessions with six randomized combinations of electrolytes concentrations of the dialysis bath (K(+), 2 and 3 mmol/L; Ca(2+), 1.25, 1.5, and 1.75 mmol/L). The effect of different dialysis baths on QT interval was significant (P < 0.05). The longest mean QTc was observed with the lowest K(+) (2 mmol/L) and Ca(2+) concentrations (1.25 mmol/L), whereas the shortest mean QTc was observed with the highest K(+) (3 mmol/L) and Ca(2+) concentrations (1.75 mmol/L). QTc was >440 ms in 9 of 16 patients (56%) at the lowest Ca(2+) and K(+) concentrations, and in 3 of 16 patients (18%) at the highest electrolytes level. Changes in QTc during the HD sessions were inversely correlated with that in total Ca and Ca(2+) plasma concentrations (P < 0.0001). CONCLUSION: Changes in ventricular repolarization duration associated with HD largely depend on the concentrations of Ca(2+) and K(+) in the dialysis bath. These findings may have important implications for the choice of the electrolytes concentration of the dialysis bath during the HD session.

Optical dialysis adequacy sensor: wavelength dependence of the ultra violet absorbance in the spent dialysate to the removed solutes.

A need for dialysate-based, on-line, continuous monitoring systems for the control of dialysis efficiency and the prevention of dialysis-associated complications is arisen due to increasing number of dialysis patients and related treatment quality requirements. The aim of this study was to investigate the wavelength dependence between the the ultra-violet (UV) absorbance in the spent dialysate and the retained solutes removed during the hemodialysis in order to explain possibilities to estimate removal of the solutes by the optical dialysis adequacy sensor. Ten uremic patients, during 30 hemodialysis treatments, were followed at the Department of Dialysis and Nephrology, North-Estonian Regional Hospital. The dialysate samples were taken and analyzed with spectrophotometer to get absorbance spectra. The results confirm previous studies considering similarity for the UV-spectrum on the spent dialysate samples during a single dialysis session indicating presence of the same type of chromophores in the spent dialysate removed from the patient's blood for different patients groups. At the same time the highest correlation in the spent dialysate for urea, creatinine, potassium, and phosphate was obtained at the wavelength 237 nm that is a new finding compared to earlier results. The highest correlation between the UV-absorbance and uric acid in the spent dialysate was obtained at the wavelength 294 nm. Presence of at least two different wavelength ranges may add selectivity for monitoring several compounds. Our study indicates that the technique has a potential to estimate the removal of retained substances.

Elevated levels of alkanals, alkenals and 4-HO-alkenals in plasma of hemodialysis patients.

BACKGROUND/AIMS: Several studies have implicated reactive carbonyl compounds (RCOs), especially those derived from lipid peroxidation, in the development of complications frequently associated with hemodialysis (HD) treatment. However, there is still much unknown regarding the nature and concentration of RCOs in HD patients. This study was designed to evaluate the level of toxic aldehydes in the plasma of HD patients and to determine the extent to which these aldehydes contribute to RCO toxicity among these patients. METHODS: 15 aldehydes of the alkanal, alkenal and 4-HO-alkenal type were measured in the plasma of 17 HD patients and 20 healthy controls. In addition, protein modification markers such as carbonyl content (CO), free thiol (SH) and residual free amino groups, as well as amyloid fibrils were also determined. RESULTS: 11 of the 15 aldehydes were significantly elevated in the HD group when compared with the controls. Correlation studies in the HD group revealed high relationships between total alkenals plus total 4-HO-alkenals versus CO, total alkanals versus NH2, total aldehydes versus SH, and total 4-HO-alkenals versus fibril. CONCLUSION: The increased levels of alkanals, alkenals and 4-HO-alkenals of lipid peroxidation in the plasma of HD patients may greatly contribute to the toxicity of RCOs. The pattern of modification of plasma protein by each group of aldehydes may provide new evidence on the in vivo mechanisms of toxicity triggered by these aldehydes on their target molecules.

Integration of peritoneal dialysis in the treatment of uremia.

The real integration of a specific therapy into the renal replacement program is represented by the possibility of easy and free patient transfer from one treatment to another without restrictions. In the case of peritoneal dialysis we feel that its integration in the therapeutic approach of uremia represents an ethical obligation for the physician, a clinical opportunity for the patient and a good cost/benefit solution for care givers. A full conviction that peritoneal dialysis represents a real therapeutic option for ESRD patients is necessary to achieve a real integration of this therapy in the uremia treatment program. A positive cost benefit ratio, both from the clinical and the economical points of view must also be seeked. The patient indirectly, must receive the same positive conviction, based on solid data and clinical results, comparable to those achievable in hemodialysis. Furthermore the patient must know that such treatment will provide an equal opportunity for kidney transplant compared to other therapies. Such a kind of feeling and knowledge must include information on patient's survival, rate of complications, treatment adequacy, availability of different techniques within the treatment and complete summary of advantages and disadvantages.

Optical dialysis adequacy sensor: contribution of chromophores to the ultra violet absorbance in the spent dialysate.

Several on-line methods have been developed to standardize the assessment of dialysis adequacy. Earlier studies have demonstrated that on-line monitoring of total ultra violet (UV) absorbance in spent dialysate can be utilized to follow continuously a single hemodialysis session. The aim of this study was to investigate the contribution of different compounds, acting as chromophores, to the UV-absorbance in the spent dialysate in order to explain origin of the cumulative and integrated UV-absorbance measured by the optical dialysis adequacy sensor. Four uremic patients, during 12 hemodialysis treatments, were followed by the optical dialysis adequacy sensor using the wavelength of 280 mn. The dialysate samples were taken and analyzed using reversed phase high performance liquid chromatography (HPLC). The total number of detected peaks from the HPLC gradient separation profiles measured at the wavelength 280 nm for the samples collected 10 mm after the start of hemodialysis (Mean +/- SD) was 38 +/- 6. The relative contribution from the area of 10 main peaks to the total area of all detected peaks in percentage was 91.01 +/- 2.52 %. The optical dialysis adequacy sensor provides continuous, on-line hemodialysis measurements and may immediately identify and alert to any deviations in the dialysis. Our study indicates that there exists a number of prevalent compounds that are the main cause of the cumulative and integrated UV- absorbance.

Demographics, diabetes type, and degree of rehabilitation in diabetic patients on maintenance hemodialysis in Brooklyn.

A point prevalence study of 232 uremic diabetics undergoing maintenance hemodialysis was conducted at fourteen facilities in Brooklyn, NY, to ascertain extent of rehabilitation, diabetes type, and immediate family history of diabetes according to the diabetes type in the proband. The majority of patients were black (138, 59%) and female (131, 56%). When grouped by diabetes type, insulin-dependent (Type I) diabetics were a small minority (31, 13.4%) of the total study population. With the exception of those with onset of diabetes in childhood, there was no difference between the interval between diagnosis of diabetes and development of renal failure in Type I (15.3 +/- 8.6 years) and the overall group of diabetics (14.9 +/- 9.3 years). A history of diabetes in an immediate family member was found in 114 (49.1%) of the entire group and was approximately the same in Type I (41.9%) and Type II (52.5%) diabetics. Rehabilitation was poor for the group as a whole, with a mean Karnofsky score of 64.9 +/- 14.3, which is a level indicative of the need for assistance in everyday living, and there was an inverse correlation between increasing age and declining Karnofsky score. Factors inhibiting rehabilitation included serious vision loss in 137 (59.1%) subjects, limb amputation, and prior myocardial infarction and stroke. Only 7 of the 153 patients (4.8%) of those younger than age 65 were gainfully employed outside of the home, and only 27% of surveyed patients were able to attend to activities beyond self care. Maintenance hemodialysis, although life extending, does not induce substantive rehabilitation for the uremic diabetic.

Encefalopatias en niños con insuficiencia renal crónica / Encephalopathy in children with chronic renal insufficiency

Se realizó un estudio retrospectivo a 15 pacientes urémicos que presentaron convulsiones con el objetivo de contribuir al conocimiento de sus causas y poder mejorar las condiciones de rehabilitación, en 9, éstas se iniciaron simultáneamente con uremia al ingrso; en 2 se registraron antes de la nefropatía y en 6 se presentaron durante la evolución de su enfermedad. Se analizaron antecedentes perinatales y neurológicos, desarrollo psicomotor, diálisis o ingesta de aluminio previas, así como la presencia de hiponatremia, hipocalcemia o crisis hipertensiva al inicio del síndrome convulsivo

Encefalopatias en niños con insuficiencia renal crónica / Encephalopathy in children with chronic renal insufficiency

Se realizó un estudio retrospectivo a 15 pacientes urémicos que presentaron convulsiones con el objetivo de contribuir al conocimiento de sus causas y poder mejorar las condiciones de rehabilitación, en 9, éstas se iniciaron simultáneamente con uremia al ingrso; en 2 se registraron antes de la nefropatía y en 6 se presentaron durante la evolución de su enfermedad. Se analizaron antecedentes perinatales y neurológicos, desarrollo psicomotor, diálisis o ingesta de aluminio previas, así como la presencia de hiponatremia, hipocalcemia o crisis hipertensiva al inicio del síndrome convulsivo

Present status of hemoperfusion/hemodialysis in Italy.

The use of charcoal hemoperfusion in the treatment of chronic renal failure has been proposed and applied by several authors. The availability of coating membranes of increased biocompatibility currently allows a safer and wider use of this purifying technique. It has been recently demonstrated that long-term treatment with combined hemodialysis/hemoperfusion yields an improvement of certain dialysis-resistant uremic signs in patients on regular dialysis treatment, while in selected patients it affords a marked reduction (up to one-third) in the overall time of treatment per week. The tolerance of long-term treatment is good. In line with these findings, a multicenter study has been carried out in Italy with two main aims: (1) to see whether long-term treatment with charcoal hemoperfusion is really safe and substantially free from side effects; (2) to verify in a larger and more varied population of patients whether such long-term treatment actually improves certain uremic signs persisting despite adequate dialysis treatment. A third phase of the multicentric study (reducing the weekly time of treatment) is currently being worked on. Five nephrology and dialysis departments took part in the study: in Bologna, Rome, Chieti, Ancona, and Lecce.

Hemodialysis for uremic schizophrenics: no psychiatric improvement.

Two uremic schizophrenics received 73 and 26 hemodialyses in 33 and 18 weeks respectively. Serial objective psychiatric scales were applied and indicated lack of improvement of schizophrenia during dialysis therapy. Further trials with hemodialysis on uremic schizophrenics need to be undertaken before this investigational therapy is offered for non-uremic schizophrenics.