Increase of nocturnal melatonin levels in hemodialyzed patients after parathyroidectomy: a pilot study.

In hemodialyzed patients hormonal disturbances are known to occur. However, melatonin levels have not been completely studied. The aim of the study was to find whether changes in calcaemia affect melatonin secretion. For this reason we followed the nocturnal serum concentrations of melatonin and parathyroid hormone (PTH) in 9 hemodialyzed patients (6 women and 3 men, aged 37-65 years) both before and 1-3 months after parathyroidectomy at 6 p.m., 9 p.m., 11 p.m., 2 a.m., 5 a.m. and 7 a.m. At 6 p.m. blood samples to evaluate the levels of calcium and phosphate were also collected. Parathyroidectomy resulted in an increase in nocturnal melatonin levels. As expected, the parathyroidectomy was followed by considerable PTH decrease. PTH showed no nocturnal variation before or after parathyroidectomy. Calcium levels significantly decreased after the operation while phosphate levels increased. In summary, in hemodialyzed patients with hyperparathyroidism, parathyroidectomy significantly increases the nocturnal secretion of melatonin. Relationships between the pineal gland and parathyroid glands have yet to be elucidated.

Continuous blood volume monitoring and "dry weight" assessment.

There are two distinct facets of adequate fluid balance control in haemodialysis patients--estimation of dry weight (DW) as the target and adequate ultrafiltration (UF) strategy, i.e. the way to reach the target in a possibly symptom-free way. The article reviews the continuous blood volume monitoring (CBVM) based procedures to deal with the former facet-DW determination. The existing approaches are divided in three groups--methods defining certain alert value of relative blood volume (RBV) reduction, methods working with RBV response to constant UF rate, and methods evaluating dynamics of RBV response to UF pulse or chain of UF pulses. While the first and the third approaches are relatively easy to automate, the second group of methods are suitable mainly for observational evaluations only. All the discussed methods, without exception, need large-scale verification, as they all were evaluated in the majority by their authors only and on small patient cohorts.

[Management of vascular access: monitoring and surveillance]. / Management des Gefässzugangs: Beobachtung und Uberwachung.

This article reviews vascular access (VA) assessment methods and procedures. It gives an overview of the existing methods for bed-side VA assessment by means of pressures, recirculation and access flow measurement. Pros and cons of the methods are discussed and additional benefits of a combined recirculation and access flow measurement are explained. Present vascular access care guidelines are discussed, namely the K/DOQI and EVAS documents. Practical setup of a vascular access monitoring and surveillance system is illustrated with data from the authors' own unit where such a system has been in use since 1999. The issue of adequate target setting is analysed in view of published works on clinical impact of access surveillance system introduction (timely detection of access stenosis and access patency). Critical re-evaluation is needed especially in current QVA threshold and intervention timing.

[Renal bone disease]. / Renální kostní choroba.

Renal bone disease is a serious complication associated with chronic renal failure. The pathogenetic mechanisms are very complicated. The disorder develops as a result of hypophosphataemia, hypocalcaemia and calcitrol deficiency already during the period when renal functions decline below 50%. Formerly the form with an excessive bone turnover predominated, nowadays we encounter ever more frequently so-called a dynamic bone disease. A serious manifestation are extraosseous calcifications. In treatment phosphate binding substances in the gastrointestinal tract are involved (along with other provisions, correcting hypophosphataemia), supplementation of calcium in case of hypocalcaemia correction of metabolic acidosis and administration of the active vitamin D metabolite (continuously as supplementation in deficient endogenous production, in a pulsatile pattern with the aim to suppress the activity of parathyroid bodies). In case of "resistant" hyperparathyroidism surgery is indicated (parathyroidectomy). Treatment of the dynamic form is not known, prevention of suppression of excessive parathyroid activity is important. New trends in the treatment of renal bone disease are non-calcium phosphate binding substances in the gastrointestinal tract, vitamin D analogues (with a lower hypercalcaemic potential) and calcium mimetics.

[The calciphylaxis syndrome as a complication of chronic kidney failure. 6 case reports and literature review]. / Syndrom kalcifylaxe jako komplikace chronického selhání ledvin. Popis sesti kasuistik a literární prehled.

Calciphylaxis is a rate complication of unknown pathogenesis in patients with end stage renal disease. It is characterized by calcification of tunica media of small arteries associated with intimal fibrosis and thrombus formation which leads to the development of skin and subcutaneous tissue necrosis. Superinfection of skin lesions is a common consequence of this syndrome which may lead to the sepsis. The prognosis of this condition in serious. We performed a retrospective study of 6 subjects (4 men and 2 women) in the age of 35 to 59 years. We followed the parameters of calcium-phosphate metabolism, presence of calciphylaxis risk factors and the effect of parathyreoidectomy. Five patients were on hemodialysis, one had a kidney transplant. Skin and subcutaneous tissue necrosis were present in all subjects. The serum levels of parathormone were either high, normal or low, levels of calcium were normal or slightly elevated and phosphate levels were high or normal. Calcium was substituted before calciphylaxis development in 5 patients, calcitriole in 3 of therm. Five patients underwent parathyroidectomy. Three patients died (all of sepsis), one patient had the lower into amputation for infected lesions and the remaining two achieved regression. Our findings do support the hypothesis that calcium and calcitriole administration participates in development of calciphylaxis. Fatal prognosis of the once infections skin lesions was also proved.

[Viral hepatitis of patients in a regular haemodialysis programme]. / Virové hepatitidy u pacientu v pravidelném hemodialyzacním programu.

After cardiovascular diseases and bacterial infections viral hepatitis is the most frequent disease which complicates haemodialyzation treatment of patients with chronic renal failure. Substitution of renal function is for these patients a life saving procedure. It is, however, complicated treatment associated with various risks of acute and chronic complications. The prevalence of parenterally transmitted viral hepatitis in the population of haemodialyzed patients is by far higher than the prevalence of these diseases in the general population. There are several reasons for this condition. In addition to the character of this treatment there is also the fact that for reasons of immunodeficiency the course proper of infetious hepatitis in haemodialyzed patients is markedly more often terminated by development of the chronic state of the disease with permanent viraemia. These patients become a possible source of infection of the other patients and possibly also the staff of haemodialyzation centres. Vaccination against viral hepatitis B reduces the risk of transmission of the disease. However a large proportion of patients is enlisted in the haemodialyzation programme acutely without the possibility of previous vaccination. Some patients who are vaccinated during the predialyzation period do not respond by antibody formation. Viral hepatitis complicates or makes it impossible in some cases to include the patient in the transplantation programme. The prevalence of viral hepatitis in patients in the haemodialyzation programme was significantly reduced despite all mentioned facts. During the last three years a certain stagnation of this positive trend was recorded. New therapeutic possibilities (the use of interferon and new antiviral properations--analogues of nucleoside bases) offer a chance of a further decrease of the number of these serious diseases.

[Effect of treatment with recombinant erythropoietin in patients with multiple myeloma and kidney failure]. / Efekt lécby rekombinantním erytropoetinem u pacientu s mnohocetným myelomem a selháním ledvin.

The efficacy of recombinant human erythropoietin (r-HuEPO) in patients with multiple myeloma (MM) has been confirmed in several clinical trials. We report our experience of r-HuEPO treatment in 5 myeloma patients with renal failure. The therapy with r-HuEPO (Eprex, Janssen-Cilag or Recormon, Boehringer, Mannheim) was started after 4-8 months from diagnosis, the drug was administered intravenously (in one patient subcutaneously after cessation of hemodialysis treatment), two or three times weekly. The initial doses were 4-12,000 units/week (mean 8,400). In all patients good response during the first month of therapy was observed. Median Hb and hematocrit increased from 70 g/l and 20.8% to 87 g/l and 26% after 1 month and to 105 g/l and 30.3% after 4-6 months, respectively. The need for blood transfusion decreased significantly--from 2.72 TU/month to 0.13 TU/month. WHO performance status and patients self-assessment of quality of live improved substantially after r-HuEPO. No serious adverse events, including hypertension and/or thromboembolic events were observed. In accordance with some previous reports we conclude r-HuEPO is effective and safe treatment in patients with MM and renal failure. Moreover, lower doses of growth factor could be effective in this particular group of patients.

[Iron supplementation during erythropoietin therapy in patients on hemodialysis]. / Doplnování zeleza pri lécbe erytropoetinem u hemodialyzovaných pacientu.

The development of secondary anaemia is a constant associated phenomenon of chronic renal failure. During its treatment by recombinant human erythropoietin (rHuEPO) erythropoiesis is accelerated and this increases demands on the supply of dietary erythropoietic precursors (Fe, pyridoxine, folic acid, vitamin B12). In particular as regards iron, frequently the dietary amount is not sufficient and supplementation is necessary. The objective of the present work is to compare oral and intravenous iron supplementation in the treatment of secondary anaemia by rHuEPO in patients with chronic renal failure treated by haemodialysis. A group of haemodialyzed patients (n = 61) treated with erythropoietin, where the serum ferritin concentration had dropped beneath 300 ng/ml, or the transferrin concentration below 0.20 was divided at random into two sub-groups. To group "A" Actiferrin was administered 3 x 1 cps/d (Ferrosi sulfas heptahydricus, corresponding to 34.5 mg elemental Fe and serine 129 mg per capsule, i.e. a total of 724.5 mg elemental Fe per week). To group "A" Ferrum-Lek was administered 1 vial per week by the i.v. route (Ferri oxidum saccharatum, corresponding to 100 mg elemental iron per week). The two groups were comparable as to the mean erythropoietin dose (50 U/kg per week) and the patients' mean age (61 years), the male/female ratio and the spectrum of basic diseases. After six weeks of treatment a comparable increase of the haematocrit and serum iron concentration was observed in both groups. As to transferrin saturation, there was a more marked increment in the intravenously supplemented group. The serum ferritin values in group "A" declined, while in group "F" they increased. After both types of iron supplementation a comparable increase of the haematocrit and serum iron concentration occurred, the iron reserves represented by serum ferritin differed however and from the long-term aspect they are in favour of intravenous iron supplementation in haemodialyzed patients treated with erythropoietin.