Usefulness of urinary parameters in advanced chronic kidney disease. / Utilidad de los parámetros urinarios en la enfermedad renal crónica avanzada.

This review discusses the diagnostic value of urinary parameters in the setting of advanced chronic kidney disease and we present the key concepts that summarise the suggestions of the manuscript. URINARY VOLUME: The amount of fluid intake may be a non-established risk factor for CKD. For these patients, a urinary output ≥2-3 l/day is a reasonable proposal. This recommendation is not applicable to patients with cardiorenal syndrome or fluid overload risk. NA: This determination is very useful to monitor salt intake. Reducing urinary Na<120 mEq/day (≅salt intake≤5-6g) is a reasonable objective. URINARY UREA NITROGEN (UUN): This parameter is useful to estimate protein intake (Maroni BJ equation). A protein intake between 48-72g (0.8-0.9g/kg/day according to weight) is equivalent to UUN 7-10g/day approximately. ACID LOAD AND POTASSIUM: Acid load reduction may be an additional strategy in the nutritional management of this population. It may be estimated indirectly from a diet survey or by measuring the elimination of UUN and Kur. The limits of this recommendation have not been established, but we propose a cautious and prudent diet of fruit and vegetables. PHOSPHORUS: There is a significant positive correlation between phosphorus and protein, both in dietary records and urine elimination. Based on this information, we suggest a urinary P excretion<800mg/day or<600mg/day for patients with GFR<25ml/min or<15ml/min, respectively. CONCLUSION: Urinary parameters provide sensitive and useful knowledge for clinical practice, provide information about the dietary habits of patients and the adherence to our recommendations.

Analysis of emergency Department Frequentation among patients with advanced CKD (chronic kidney disease): Lessons to optimise scheduled renal replacement therapy initiation. / Análisis de la frecuentación de Urgencias en consulta ERCA (enfermedad renal crónica avanzada): enseñanzas para optimizar el inicio programado en tratamiento renal sustitutivo.

The decision to initiate renal replacement therapy (RRT) implies a wide margin of uncertainty. Glomerular filtration rate (GFR) tells us the magnitude of renal damage. Proteinuria indicates the speed of progression. However, nowadays more than 50% of patients are still initiating RRT hastily, and it is life threatening. HYPOTHESIS: By analysing Emergency Department (ED) frequentation and causes of a hurried initiation, we can better schedule the timing of the start of RRT. METHOD: Retrospective and observational study of all CKD patients in our outpatient clinic. ED frequentation and hospitalisation (Hos) time were reviewed during a 12-month period. We analysed: 1) time at risk, purpose (modality of RRT), previous comorbidity; 2) causes of ED frequentation and Hos; 3) type of initiation: «scheduled¼ vs. «non-scheduled¼, and within these «non-planned¼ vs. «potentially planned¼. RESULTS: Of a total of 267 patients (time at risk 63.987 days, 70±13 years, 67% males, 38% diabetics), 68 (25%) patients came to hospital on 97 occasions: 39 only ED, 46 ED+Hos and 12 only Hos. ED frequentation was one patient every 4.3 days, and bed occupation was almost 3 per day. Main causes: 47% cardiopulmonary (1/3 heart failure), 11% vascular peripheral+cerebral, 11% gastrointestinal: 8/11 due to bleeding (all with anticoagulants/antiplatelet agents). Thirty-one (12%) patients initiated RRT: of these, 14 (45%) were scheduled (6 PD, 6 HD, and 2 living donor RTx), and 17 (55%) were not scheduled or were rushed, all with venous central catheter. Following the objectives of this study, the non-scheduled group were itemised into 2 groups: 9 non-planned (initial indication of conservative management or patient's refusal to undergo dialysis, and diverse social circumstances not controllable by the nephrologist) and 8 were considered potentially planned (6 heart failure, one gastrointestinal bleeding and one peripheral vascular complication). This last group (potentially planned), when compared with the 14 patients who started treatment in a scheduled manner, had significant differences in that they were older, with more previous cardiac events, and GFR almost double that of the other group. All of them started treatment in the ED. CONCLUSION: This analysis provides us with knowledge on those patients who may benefit from an earlier preparation in RRT. We suggest that patients with previous cardiac events, especially with a risk of gastrointestinal bleeding, should start the preparation for RRT even with GFR rates of 20-25ml/min. In spite of the retrospective nature of this study, and taking into account the difficulties of carrying out clinical trials in this population, we propose this suggestion as complementary to the current recommendations for a scheduled start using this technique.

Cost analysis and sociocultural profile of kidney patients. Impact of the treatment method.

BACKGROUND: The cost analysis of chronic kidney disease based on individual data for treatment methods and components has not been published in Spain. OBJECTIVES: a) To study the health costs of a year of treatment with haemodialysis (HD), deceased donor renal transplantation (RTx), renal-pancreas transplantation (RPTx), and S4 and S5 advanced chronic kidney disease (ACKD) b) Assess the potential relationship between sociocultural diversity, costs and treatment method. METHODS: Observational study of: 1) 81 patients with ACKD (53 S4 and 28 S5) 2) 162 with more than 3 months on HD and 3) 173 with a Tx for more than 6 months (140 RTx and 33 RPTx). The costs were assessed in five categories: 1) HD sessions, 2) drug intake, 3) hospitalisation, 4) outpatient care and 5) transportation. We carried out a survey with socio-demographic parameters. RESULTS: The financial impact of HD was €47,714±18,360 (mean±SD), that of Tx €13,988±9970, and that of ACKD €9654±9412. The cost of HD was the highest in all financial items. The costs were similar between RTx and RPTx. In ACKD, the greater the renal deterioration, the greater the cost is (S4 €7846±8901 versus S5 €13,300±9820, P<.01). Tx patients had the best sociocultural status, while HD patients had the worst profile. We did not find differences in costs between the three sociocultural groups. CONCLUSIONS: HD has the greatest financial impact in all items, five times higher than the ACKD patient cost and three times than the Tx patient cost. Optimising early prevention and Tx, if appropriate, must be priority strategies. This analysis invites us to think about whether sociocultural status can have an influence on opportunities for Tx.

Vitamin D and proteinuria: a critical review of molecular bases and clinical experience.

Proteinuria is the main predictor of chronic kidney disease progression. Drugs that block the renin-angiotensin-aldosterone (RAA) system reduce proteinuria and slow down the progression of the disease. However, their effect is suboptimal, and residual proteinuria persists as an important predictor of renal impairment. Vitamin D has pleiotropic effects that could have an impact on these parameters. In this study, we critically review the molecular and experimental bases that suggest an antiproteinuric effect of vitamin D receptor (VDR) activation and the available evidence on its antiproteinuric effect in clinical practice. In animal models, we have observed the antiproteinuric effect of VDR activation, which could be due to direct protective action on the podocyte or other pleiotropic effects that slow down RAA system activation, inflammation and fibrosis. Clinical trials have generally been conducted in patients with a vitamin D deficiency or insufficiency and the main trial (VITAL) did not demonstrate that paricalcitol improved the study's primary endpoint (decrease in the urine albumin to creatinine ratio). In this sense, the information available is insufficient to advise the use of native vitamin D or VDR activators as renoprotective antiproteinuric drugs beyond the experimental level. Two Spanish clinical trials and one Italian trial attempted to determine the effect of paricalcitol and vitamin D on residual proteinuria in various clinical circumstances (PALIFE, NEFROVID and PROCEED).

Patients treated with plasmapheresis: a case review from University Hospital of the Canary Islands.

INTRODUCTION: Plasmapheresis (PP) is a therapeutic apheresis technique used in the treatment of various renal and systemic diseases with varying degrees of proven clinical efficacy. OBJECTIVE: To review our experience with PP at the Hospital Universitario de Canarias, focused on effectiveness and safety results in different disease groups. MATERIAL AND METHODS: A retrospective-descriptive study of patients treated with PP from 01/01/2006 to 31/12/2009 at the hospital. We analysed medical histories and demographic data (sex, age), biochemical parameters, underlying disease, volume and type of replacement used in the PP sessions (5% human albumin and/or fresh frozen plasma), complications with the technique, delay in starting PP treatment after suspected clinical diagnosis, number of PP sessions received, patient mortality, degree of renal impairment and evolution of renal function. RESULTS: There were 51 patients studied, aged 50±18 years, of whom 60% were male; 331 PP sessions were performed. The diseases treated were grouped as: 11 vasculitis, 15 transplant immune activation, 5 haemolytic-uraemic syndrome (HUS), 7 idiopathic or thrombotic thrombocytopaenic purpura, 2 foetal Rh immunisations, 2 haematological diseases, 4 neurological diseases, among others. Overall mortality was 19.6% (n=10): 6 cases secondary to septic shock and the rest as a result of the evolution of the underlying disease, with 1 due to haemorrhagic shock in the renal biopsy area. There were no deaths in the transplant immune activation group. In the vasculitis group, there were 3 deaths (2 secondary to septic shock). Of the 10 patients who died, 9 did so within the first three months after diagnosis. Of the 26 renal biopsies performed, the most frequent indications were: vasculitis (23%), humoral rejection (42%), humoral rejection with calcineurin-inhibitor toxicity (12%) and HUS (8%), among others. Haemodialysis (HD) was required by 24 patients at the start of clinical symptoms: 9 of the 11 patients with vasculitis, 4 of the 5 patients with HUS and 5 of the 15 patients with transplant immune activation. At the end of evolution, 14 of them remained on the HD programme: 5 of the 11 patients with vasculitis, 2 of the 15 transplant patients and 3 of the 5 HUS patients. Significantly, patients who developed end kiney disease (EKD) in the vasculitis group were older and had higher creatinine at the onset of the disease. The transplant patients were monitored for anti-HLA class I or II before and after PP; there was a mean decrease of antibody titres in all but one patient; with an average decrease of 51% to 31%. In general, the PP technique was virtually free of complications. There were only 5 (3%) mild-moderate reactions to fresh plasma (perioral tingling and urticarial reactions) requiring pre-medication with steroids, but which did not lead to discontinuation of the treatment. CONCLUSION: Taking into account the wide variety of diseases that can benefit from PP and the nature of some of them, publishing our experience with this therapeutic method is of great importance. By increasing the description of case series by centre, we can add survival and renal function evidence in many uncommon diseases. Our study provides useful information for clinical practice and has also led us to reflect on future strategies to optimise outcomes in our patients.

Management of hyperphosphataemia in dialysis patients: role of phosphate binders in the elderly.

Phosphorus control remains a relevant clinical problem in dialysis patients. With age, however, serum phosphorus level decreases significantly because of a spontaneous decrease in protein intake. Older patients usually need lower doses of phosphorus binders. Nevertheless, hyperphosphataemia is observed in a quarter of patients aged >65 years. Phosphorus retention is related to an imbalance between phosphorus intake and removal by dialysis, and is usually aggravated when vitamin D analogues are employed. Hyperphosphataemia induces secondary hyperparathyroidism and the development of osteitis fibrosa. Recent publications describe an association between phosphorus retention and increased calcium and phosphorus product (Ca2+ x P), with significant progression of tissue calcification and higher mortality risk. Dietary intervention, phosphorus removal during dialysis and phosphorus binders are current methods for the management of hyperphosphataemia. However, the phosphorus removed by standard haemodialysis is insufficient to achieve a neutral phosphorus balance when protein intake is >50 g/day. Additional protein restriction may impose the risk of a negative protein balance. More frequent dialysis may help to control resistant hyperphosphataemia. Phosphorus binders constitute the mainstay of serum phosphorus level control in end-stage renal disease patients. Aluminium-based phosphorus binders, associated with toxic effects, have largely been substituted by calcium-based phosphorus binders. However, widespread use of calcium-based phosphorus binders has evidenced the frequent appearance of hypercalcaemia and long-term progressive cardiovascular calcification. Sevelamer, a relatively new phosphorus binder, has proved efficacious in lowering serum phosphorus and parathyroid hormone (PTH) levels without inducing hypercalcaemia. Furthermore, several investigators have reported that sevelamer may prevent progression of coronary calcification. However, its efficacy in severe cases of hyperphosphataemia remains to be confirmed in large series. There are no specific guidelines for phosphorus control in the elderly. Until more information is available, levels of mineral metabolites should be targeted in the same range as those recommended for the general population on dialysis (calcium 8.7-10.2 mg/dL, phosphorus 3.5-5.5 mg/dL and Ca2+ x P 50-55 mg2/dL2). PTH values over 120 ng/L help to avoid adynamic bone disease. Since elderly patients have a higher incidence of adynamic bone (which buffers less calcium) and vascular calcification, sevelamer should be the phosphorus binder of choice in this population; but sevelamer is costly and its long-term efficacy has not been definitively validated. Patients with low normal levels of calcium may receive calcium-based phosphorus binders with little risk. Patients with low values of PTH and high normal calcium should receive sevelamer. Tailored combinations of calcium-based phosphorus binders and sevelamer should be considered, and calcium dialysate concentration adjusted accordingly.