[Renal pathophysiology and pharmacological mechanisms of nephroprotection]. / Fisiopatología renal y mecanismos farmacológicos de nefroprotección.

Several risk factors may affect the progression of chronic kidney disease (CKD). Arterial hypertension, proteinuria, obesity, intraglomerular hypertension, smoking and metabolic control in diabetes mellitus are the main modifiable risk factors for progression. The progression of CKD involves many cellular processes that originate in specific compartments of the kidney, the vascular compartment with nephroangiosclerosis and the tubulointerstitial compartment with fibrosis and tubulointerstitial atrophy, and there may be overlap between both mechanisms. Given the involvement of so many risk factors and so many pathogenic pathways in the progression of CKD, the best hope for delaying or preventing the progression of CKD lies in a combined and multidisciplinary therapeutic approach, based on the existing evidence and acting on all these processes and pathways from the mechanistic point of view, and on a global process that is cardiovascular and renal risk to improve the prognosis of patients.

[COVID-19 and cardiovascular and kidney disease: Where are we? Where are we going?] / COVID-19 y enfermedad cardiovascular y renal: ¿Dónde estamos? ¿Hacia dónde vamos?

The SARS-CoV-2 pandemic is a global health emergency and we need to know more about it. Patients with cardiovascular risk and previous kidney risk have been identified as especially vulnerable for greater morbidity and mortality when they suffer from COVID-19. A considerable proportion of patients can develop a vascular lesion in the context of the disease that entails a greater lethality. Cardiovascular and renal complications represent a problem and, probably in the near future, may pose a threat to patients who have survived COVID-19. As physicians, we cannot forget that during an epidemic like this, other chronic diseases are present, and patients continue to require care. We are obliged to monitor even more intensely their treatments and control degree. Furthermore, we must not forget that urgent situations continue to arise in this pandemic situation and require prompt attention. In this current situation, it is very likely that many patients, out of fear, have not sought medical attention. The situation during the epidemic and the uncertainty of the post-COVID-19 period, requires intensification in the control and monitoring of cardiovascular and kidney disease in our patients. Primary care constitutes a key level of care for the care of the population with cardiovascular disease. Likewise, and in the face of this new health scenario, we need to promote the prevention and control measures that emanate from the studies currently underway. Now, more than ever, we need research, crucial to improve the cardiovascular and renal prognosis of our patients.

[Tools to improve efficiency in the clinical management of hypertensive patients]. / Herramienta para mejorar la eficiencia en el manejo clínico de pacientes hipertensos.

OBJECTIVE: To create a tool to evaluate the efficiency of the clinical management of hypertensive patients in Primary Care. MATERIAL AND METHODS: A web-based questionnaire was designed for Primary Care centres to self-evaluate the management of hypertension in five specific areas: information systems, diagnostic and analytical tests, organisational aspects, use of resources, and continuous training programmes for patients and healthcare professionals. A committee of experts previously defined these questions and their ideal responses or "control", based on the scientific literature or, if there were no published references, by consensus of the committee. A descriptive analysis was performed on the data, and an adherence score was created that ranged from 0 (no adherence) to 1 (total adherence). RESULTS: A total of 35 Primary Care centres entered their data into the website for the clinical management of hypertensive patients. The highest adherence to the ideal algorithm was observed in the area "Diagnostic and analytical tests" (0.69±0.10), and the lowest in "Continuous training programmes for patients and professionals" (0.42±0.21). CONCLUSIONS: The efficiency of clinical management in hypertensive patients can be analysed using the website tool created for this purpose. Its use allows an internal audit to detect the areas that need improvement, and also serves to make comparative evaluations in the different areas of management over time.

[Positioning for the management of arterial hypertension in Primary Care from the critical analysis of the American (2017) and European (2018) guidelines. Spanish Society of Primary Care Physicians (SEMERGEN)]. / Posicionamiento para el manejo de la hipertensión arterial en atención primaria a partir del análisis crítico de las guías americana (2017) y europea (2018). Sociedad Española de Médicos de Atención Primaria (SEMERGEN).

The Scientific Societies of Primary Care, being the area in which there is a considerable prevalence of Arterial Hypertension (AHT), need to periodically evaluate the international guidelines for its management. This is particularly relevant when disparate guidelines make it difficult to make decisions in daily clinical practice. The present document has as its aim to analyse the changes and new developments proposed in the guidelines of the American College of Cardiology and the American Heart Association (ACC/AHA 2017), as well as in the guidelines of the European Society of Cardiology and European Society of Hypertension (ESC/ESH 2018). An analysis will be made of any differences, limitations, and their applicability to Primary Care in Spain. Finally, the most relevant available and appropriate information is extracted and integrated in order to homogenise the care of the hypertensive patient, from a critical, but also a reasoned, perspective. The discrepancies between the recommendations in such essential aspects as the management of the disease, require the compiling and critical analysis of the information that enables us as scientific society, interested in providing all PC physicians with the most relevant, and at the same time, sensible, recommendations of all the guidelines.

[Unawareness of the K/DOQI guidelines for bone and mineral metabolism in predialysis chronic kidney disease: results of the OSERCE Spanish multicenter-study survey]. / Desconocimiento de las guías K/DOQI sobre la alteración del metabolismo óseo-mineral asociada a la enfermedad renal crónica no en diálisis: resultados de la encuesta en el estudio multicéntrico español OSERCE.

Since its publication in 2003, the K/DOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease (CKD) have become a worldwide reference. The aim of this study was to analyze the observance to these guidelines in patients with a glomerular filtration rate < 60 ml/min/1,73m2 not yet included in dialysis in a Spanish multicenter cohort. A questionnaire by investigator/centre was completed by 32 different nephrologists participating in the OSERCE study and representing the overall Spanish public health net. We observed that biochemical parameters were measured less frequently than recommended, except in CKD stage 3. The therapeutic goals for intact PTH were not properly reported by 59 % of the consulted nephrologists for stages 3 and 4, whereas only 22% did not report them properly for stage 5. The goals for phosphorus were not adequately reported in 50 % of cases (stages 3 y 4) and 60 % (stage 5). For calcium, these values were 70 %, 73.3 % and 65.5 % for stages 3, 4 and 5, respectively. A corrected plasma calcium between 9.5 and 10.2 mg/dl is still considered adequate for 31%. As much as 87% nephrologists stated that they did not sistematically measure calcidiol plasma levels. In general, these results demonstrate that there is a great degree of unawareness of K/DOQITM predialysis guidelines. Thus, their poor implementation is probably not only due to the lower availability of approved therapeutic agents, the difficult achievement of goals or the disbelief on current recommendations. It would be desirable that forthcoming guidelines such as the KDIGO could also consider the need of educational efforts for CKD-Mineral and Bone Disorder.

Sodium zirconium cyclosilicate: a new potassium binder for the treatment of hyperkalemia.

Hyperkalemia is one of the most common electrolyte disturbances, especially among some groups of patients, such as in those with chronic kidney disease, diabetes or heart failure. Hyperkalemia has been associated with increased risks of mortality, arrhythmias, hospitalization and costs, as well as the need to down titrate/discontinue renin-angiotensin-aldosterone system inhibitors (RAASIs), despite their well-known cardiovascular and nephroprotective benefits. Current potassium binders have limitations (slow onset of action, limited selectivity for potassium binding, risk of drug interactions or gastrointestinal intolerance). Sodium zirconium cyclosilicate (SZC) is a new potassium binder recently approved for the treatment of chronic hyperkalemia. It is a nonabsorbable, inorganic crystal which selectively binds potassium and ammonium in exchange of Na+ and H+ in the whole gastrointestinal tract, achieving a rapid correction of serum potassium levels (within 2 days) and maintaining normokalemia in the long term (up to 1 year), with a good safety profile (common adverse reactions include gastrointestinal events and a dose-dependent risk of edema), excellent tolerability and a low potential for drug interactions. Its potassium-lowering efficacy is maintained irrespective of the use of RAASIs. In summary, SZC is a new potassium binder recently approved for the treatment of hyperkalemia. Its differences with respect to currently available potassium binders make SZC an attractive therapeutic option.

[Anemia of chronic kidney disease: Protocol of study, management and referral to Nephrology]. / Anemia en la enfermedad renal crónica: protocolo de estudio, manejo y derivación a Nefrología.

The objective of this protocol is to know which test are needed to study an anaemia in a patient with chronic kidney disease, the differential diagnosis of renal anaemia, to know and correct other deficiency anaemias, and the criteria for referral to Nephrology or other specialties of the anaemic patient with chronic kidney disease.

[Seasonal perodicity in vascular access thrombosis for haemodialysis]. / Ritmo estacional en la trombosis del acceso vascular para hemodiálisis.

Different studies have shown that some clinical events, particularly cardiovascular and thrombotic events, show a regularity in its appearance. The aim of our study was to analyse the possible existence of seasonal periodicity in the incidence of the vascular access thrombosis in patients on chronic haemodialysis. Prospectively, we collected information of 164 patients with 250 episodes of vascular access thrombosis referred to our hospital from january 1995 to december 1999. An ANOVA test for comparison of the means, and a time series analysis were performed. During the five year study the consecutive number of thrombosis were 43, 57, 55, 59 and 36. When the different seasons were analysed, the cumulative number of events in summer during the study period were 91, a significant increase compared to spring, autumn, and winter (54, 54, and 51, respectively; p<0.001). Time series analysis confirmed that thrombolic events during summer showed an increased incidence over the mean (p<0.001), and it occurred every year. The same results were obtained when the PTFE grafts were analyzed separetely (july RR 2.62, p=0.002; august, RR 2.37, p=0.04), but not with the arteriovenous fistulae. In conclusion, this study showed a seasonal periodicity of vascular access thrombosis, with a PTFE graft. Although the causes were unknown, these data alert us on the convenience of an increased attention to the vascular access during the summer months in order to prevent its thrombosis.

[Renal transplantation with positive crossmatch]. / Trasplante renal en presencia de una prueba cruzada positiva.

INTRODUCTION: Lymphocytotoxic antibodies reduce the expectancy of renal transplantation due to the increased risk of a positive crossmatch. MATERIAL AND METHODS: We analyzed the evolution of eight kidney transplants performed in our unit in presence of a positive crossmatch with historical T and/or B lymphocyte positive crossmatches. RESULTS: Mean panel reactivity was 76,6 +/- 25,7% (r: 22-100%), been higher than 75% in six patients. Six patients were recipients of a second or third transplant. Immunosuppression consisted of quadruple therapy including induction with thymoglobuline. Five patients had delayed graft function, and one had primary non-function of the graft. One patient lost her graft due to chronic allograft nephropathy in the second year postransplantation. Six patients maintained a good renal function (serum creatinine 1,2 +/- 0,5 mg/dl, proteinuria 0,20 +/- 0,34 g/day). CONCLUSION: Renal transplantation in presence of a positive cross-match with historical serum and T lymphocytes and/or B lymphocytes, was followed by a satisfactory graft survival.

[Medical expert consensus in AH on the clinical use of triple fixed-dose antihypertensive therapy in Spain]. / Consenso de médicos expertos en HTA sobre el uso clínico de la triple terapia antihipertensiva a dosis fija en España.

INTRODUCTION: The opinion of experts (different specialties) on the triple fixed-dose antihypertensive therapy in clinical practice may differ. MATERIALS AND METHODS: Online questionnaire with controversial aspects of the triple therapy answered by panel of experts in hypertension (HT) using two-round modified Delphi method. RESULTS: The questionnaire was completed by 158 experts: Internal Medicine (49), Nephrology (26), Cardiology (83). Consensus was reached (agreement) on 27/45 items (60%); 7 items showed differences statistically significant. Consensus was reached regarding: Predictive factors in the need for combination therapy and its efficacy vs. increasing the dose of a pretreatment, and advantage of triple therapy (prescription/adherence/cost/pressure control) vs. free combination. CONCLUSIONS: This consensus provides an overview of the clinical use of triple therapy in moderate-severe and resistant/difficult to control HT.

[Vascular access guidelines for hemodialysis]. / Guías de acceso vascular en hemodiálisis.

Quality of vascular access (VA) has a remarkable influence in hemodialysis patients outcomes. Dysfunction of VA represents a capital cause of morbi-mortality of these patients as well an increase in economical. Spanish Society of Neprhology, aware of the problem, has decided to carry out a revision of the issue with the aim of providing help in comprehensión and treatment related with VA problems, and achieving an homogenization of practices in three mayor aspects: to increase arteriovenous fistula utilization as first vascular access, to increment vascular access monitoring practice and rationalise central catheters use. We present a consensus document elaborated by a multidisciplinar group composed by nephrologists, vascular surgeons, interventional radiologysts, infectious diseases specialists and nephrological nurses. Along six chapters that cover patient education, creation of VA, care, monitoring, complications and central catheters, we present the state of the art and propose guidelines for the best practice, according different evidence based degrees, with the intention to provide help at the professionals in order to make aproppiate decissions. Several quality standars are also included.

[Risk factors associated with survival in patients in a peritoneal dialysis program]. / Factores de riesgo asociados con la supervivencia en pacientes en programa de diálisis peritoneal.

The aim of this study was to quantify the effect of different mortality risk factors in peritoneal dialysis and to establish a prognostic index that could predict mortality risk when patients start dialysis. A prospective study was performed on 103 patients included in our peritoneal dialysis program. The mean follow-up time was 26 +/- 21 months. A multivariate analysis (Cox regression was made to identify different risk factors that could influence patient survival during peritoneal dialysis. Age, gender, parathyroid hormone, albumin, cholesterol, and the presence of diabetes mellitus were evaluated as potential risk factors. Patients were distributed in three groups (high, medium and low risk), according to the risk factors with a significant influence in multivariate analysis, and patient survival was studied depending on the prognostic index using Kaplan-Meier estimator. Overall patient survival was 90% (95%CI: 83 to 96%) after the first year and 40% (95%IC: 32 to 58%) after 5 years of follow-up. The Cox regression analysis identified albumin below 4 g/dL (RR: 2.57; 95% CI: 1.16 to 5.72), age older than 65 years RR: 3.10; 95%IC: 1.20 to 7.98) and diabetes mellitus (relative risk, RR: 4.36; 95%IC: 1.43 to 13.31) as independent risk factors for mortality in patients receiving peritoneal dialysis. Patient survival after two years was 40% (95%IC: 31 to 59%), 73% (95%IC: 60 a 86%) and 100% (p < 0.05), respectively. Malnutrition and related factors in patients receiving peritoneal dialysis are associated with a higher mortality rate.

[Prognostic significance of programmed dialysis in patients who initiate renal substitutive treatment. Multicenter study in Spain]. / Significado pronóstico de la diálisis programada en pacientes que inician tratamiento sustitutivo renal. Un estudio multicéntrico español.

BACKGROUND: The aim of our study was to analyse patient characteristics, mortality and costs, all of them in relation to whether starting dialysis was planned or unplanned. METHODS: A total of 362 patients (227 male and 135 female) from five hospitals of the National Health System, who were started on chronic renal replacement therapy (RRT) during 1996 and 1997 were included. Patients who were started on RRT after acute renal failure were excluded. We carried out a retrospective analysis of the demographic characteristics, patients' conditions at the time of initiating dialysis and outcome and costs at six and thirty-six months of treatment. Patients were classified as planned (PL-D) or unplanned dialysis (UNPL-D), depending on whether or not the patient had a vascular or peritoneal access ready to use for initiating RRT. RESULTS: One hundred and eighty-six patients (51.4%) started on dialysis in the PL-D group whereas 176 (48.6%) did it as UNPL-D. In this latter group, 135 (37.3% of the total) had previously been monitored by a nephrologist, and 41 (11.3%) initiated dialysis without previous nephrological follow-up. UNPL-D was associated with older age (p < 0.001), non-nephrological follow-up (p < 0.001), diabetes (34.7% vs 22.6%) (p = 0.011), haemodialysis as a first mode of RRT (94.9 vs 81.7%) (p < 0.001), higher comorbidity risk (p < 0.001), dialysis initiation with uraemic symptoms or fluid overload (p < 0.001), increased blood transfusion requirement (p < 0.001) and lower serum albumin (p < 0.001), creatinine clearance (p < 0.001), haemoglobin concentration (p < 0.001), and weight (p = 0.002). In the PL-D group the main primary renal diseases were glomerular and polycystic disease, whereas interstitial and diabetic nephropathy were higher in UNPL-D group (p = 0.005). Multivariate analysis showed that previous non nephrological follow-up, uraemic symptoms, interstitial nephritis as primary renal disease correlated with UNPL-D initiation, and it was followed by choosing haemodialysis as first RRT. UNPL-D was also associated with increased number of days of hospitalization at the initiation of dialysis, and during the first 6 months (p < 0.001), increase of hospitalization days (p = 0.009), and increased 6-month-mortality (10.2% vs 3.2%) (p = 0.015, log rank test), and three-year mortality (24.2 vs 36.9%) (p = 0.006, log rank test). The costs of UNPL-D were fivefold that of the PL-D group. CONCLUSION: UNPL-D has been associated with worse overall clinical conditions at the initiation of chronic replacement therapy, choosing haemodialysis as first RRT, increased morbi-mortality and subsequent increase of costs.

[Endoluminal percutaneous thrombectomy as a treatment for acute vascular access thrombosis: long-term results of 123 procedures]. / La trombectomía endoluminal percutánea como tratamiento de la trombosis aguda del acceso vascular: resultados a largo plazo de 123 procedimientos.

UNLABELLED: Percutaneous treatment of thrombosis of occluded vascular access (VA) for haemodialysis (HD) has been an alternative to surgical and pharmacological treatments, but long term results are not well defined. The aim of our study was to analyse the long term results of percutaneous thrombectomy as a treatment of occluded VA for HD. We conducted a prospective study from june 1995 to april 1999, including 123 consecutive thrombectomies in 64 VA in patients submitted to our hospital because of recent thrombosis of VA for HD. We used two different techniques, hydrodynamic catheter thrombectomy (Hydrolyser) in the 42 first procedures (34.1%), and since october 1996 we used mechanical balloon thrombolysis in the remaining 81 patients (65.9%). Underlying stenoses were evaluated by angiography, and treated by angioplasty. After the procedure, intravenous heparin was administered for 24 hours. The VA were 28 Brescia-Cimino arteriovenous fistulae (30.4%) and 64 PTFE grafts (69.6%). PATIENT CHARACTERISTICS: mean age: 63 +/- 15 years (18-84), previous VA: 3.3 +/- 2.5 (0-9). The mean follow-up was 10.5 +/- 8.6 months (3-35). Percutaneous thrombectomy was able to remove the clots in 120 instances (technical success: 97.5%). After the thrombectomy 15 patients (16.3%) were immediately referred to the surgeon to perform a new VA due to vascular lesions in which percutaneous treatment was not indicated. Thirteen cases (14.1%) showed early thrombosis (< 72 hours). During the follow-up, 27 cases developed thrombosis (30%) and 26 VA were still patent (28.3%). In 23% of perfusion lung scans and in 2 of the 5 angiographies performed after thrombectomy, subsegmentary or segmentary perfusion defects were detected, without clinical significance. There were no relevant undesirable effects related to the technique and no symptomatic pulmonary embolism. In summary, percutaneous thrombectomy, whether hydrodynamic or mechanical, has shown to be an efficacious treatment of VA thrombosis for HD, preserving the VA with satisfactory long-term results.

[Guidelines on hemodialysis-associated viral infections]. / Guías sobre enfermedades víricas en hemodiálisis (HD).

The viric infections influence morbi-mortality in Chronic kidney Disease patients in hemodialysis therapy and can affect to the Staff of the Units. The guides considered the most relevant virus at the present moment: C Virus, B Virus and HIV. To prevent horizontal nosocomial transmission is necessary the observance always the universal precautions in the HD units, although sometimes can appeared seroconversions and epidemic bud when exist a break of these. Is analyzed different situations with special focus in units for acute patients. The following steps under the suspicious of the epidemic bud appeared in one of the annexes together with legislation according to this case. Respect to the staff in every one of the virus is shown prevention patterns, serologic markers to perform when an accident with infected blood occur, also is considered when treatment is indicated. The guides considered too the conditions necessary for include these patients on waiting list for kidney transplantation.

[Acute renal failure after the administration of enalapril as presentation form of Takayasu's arteritis]. / Insuficiencia renal aguda tras la administración de enalapril como forma de presentación de la arteritis de Takayasu.

The case of a 19 year old patient with Takayasu arteritis with exclusive involvement of the abdominal aorta and without involvement of the renal arteries who presented severe arterial hypertension during the acute phase of the disease is referred. The administration of a dose of 20 mg of enalapril maleate was followed in less than 24 hours by lameness of the lower limbs and acute oligoanuric renal failure, both of which were reversible after discontinuation of the drug. During the inflammatory phase of the disease, treatment with high doses of prednisone was effective in the control of the general symptoms and the biologic parameters of inflammation. Surgical revascularization was successfully carried out 5 months after diagnosis. Two years later the patient continues to be normotense and asymptomatic.