[Vascular access models cause heterogeneous results in the centres of one community]. / Los modelos de atención al acceso vascular condicionan resultados heterogéneos en los centros de una misma comunidad.

INTRODUCTION: Vascular access (VA) is the main difficulty in our hemodialysis Units and there is not adequate update data in our area. PURPOSE: To describe the vascular access management models of the Autonomous Community of Madrid and to analyze the influence of the structured models in the final results. MATERIAL AND METHODS: Autonomous multicenter retrospective study. Models of VA monitoring, VA distribution 2007-2008, thrombosis rate, salvage surgery and preventive repair are reviewed. The centers are classified in three levels by the evaluation the Nephrology Departments make of their Surgery and Radiology Departments and the existence of protocols, and the ends are compared. MAIN VARIABLES: Type distribution of VA. VA thrombosis rate, preventive repair and salvage surgery. RESULTS: Data of 2.332 patients were reported from 35 out of 36 centers. Only 19 centers demonstrate database and annual evaluation of the results. Seventeen centers have multidisciplinary structured protocols. Forty-four point eight percent of the patients started dialysis by tunneled catheter (TC). Twenty-nine point five percent received dialysis by TC in December-08 vs 24.7% in December-07. Forty-four point seven percent of TC were considered final VA due to non-viable surgery, 27% are waiting for review or surgery more than 3 months. For rates study data from 27 centers (1.844 patients) were available. Native AVF and graft-AVF thrombosis rates were 10.13 and 39.91 respectively. Centers with better valued models confirmed better results in all markers: TC rates, 24.2 vs 34.1 %, p: 0.002; native AVF thrombosis rate 5.3 vs 10.7 %; native AVF preventive repair 14.5 vs 10.2%, p: 0.17; Graft- AVF thrombosis rate 19.8 vs 44.4%, p: 0.001; Graft-AVF preventive repair 83.2 vs 26.2, p < 0.001.They also have less patients with TC as a final option (32.2 vs 45.3) and less patients with TC waiting for review or surgery more than 3 months (2.8 vs 0). LIMITS: Seventy-five percent of patients were reached for the analysis of thrombosis rate. Results are not necessarily extrapolated. CONCLUSIONS: For the first time detailed data are available. TC use is elevated and increasing. Guidelines objectives are not achieved. The difference of results observed in different centers of the same public health area; make it necessary to reevaluate the various models of care and TC follow-up.

[Outpatient surgeries of patients with arteriovenous fistulas for hemodialysis. Integrated activity in a general surgery unit]. / Cirugía sin ingreso de pacientes con fístulas arteriovenosas para hemodiálisis. Actividad integrada en un servicio de cirugía general.

INTRODUCTION: The increase of prevalent haemodialysis patients is a challenge for surgery units. Vascular access related complications are the main cause of hospital admissions in many dialysis units. Outpatient surgery could decrease waiting lists, cost related and complications associated to vascular access. MATERIAL AND METHODS: We have performed a prospective study of the vascular access related surgery in a ten years period. Outpatient surgery was included with the rest of the activity in a general surgery unit and was performed by not exclusive dedicated surgeons. RESULTS: Since 1998 to December 2009 we performed 2,413 surgical interventions for creating and repairing arteriovenous fistula in 1,229 patients, including elective and emergency surgery (74.8% and 25.2% respectively). Outpatient procedures were performed in 82% of cases (89% in elective and 60% in emergency surgery). There were unexpected admissions secondary to surgical complications in 6% of patients. There wasn't postoperative mortality. The rate of admissions were 0,09 episodes and 0,2 days per patient/year. CONCLUSIONS: Outpatient surgery is possible in a high percentage of patients to perform or to repair an arteriovenous fistula, including emergency surgery. Vascular access surgery can be included in ordinary activity of a surgical unit. Outpatient vascular access surgery decreases unnecessary hospital admissions, reduces costs and nosocomial complications.

[Clinical and economic repercussions of the use of tunneled haemodialysis catheters in a health area]. / Repercusiones clínicas y económicas del uso de catéteres tunelizados de hemodiálisis en un área sanitaria.

INTRODUCTION: Tunneled catheters in hemodialysis are associated with poor prognosis, however, few prospective studies have been designed to specifically evaluate this aspect. The objective has been evaluate the impact of tunneled catheter in patient mortality and costs attributable to this procedure. METHODS: A seven years prospective cohort study was performed in all patients starting hemodialysis in our health care area adjusting for comorbidity and albumin. The study comprised 260 patients with Charlson index 7.05 +/- 2.8 (age 65.5 years, 62.3% males, 25% with diabetes mellitus and 37.7% with a previous cardiovascular event. RESULTS: The first vascular access was a catheter in 47.3%, PTFE in 11.2% and native arteriovenous fistula in 41.5%. Minimum follow-up was one year, with an average of 2.31 years/patient. The mortality risk adjusted for comorbidity was greater among the patients that started with catheterization, HR: 1.86 [1.11-3.05]. This negative effect was observed in 57.30% of those subjected to catheterization at any stage (HR: 1.68 [1.00-2.84] and proved to be time dependent, i.e., the longer catheterization, the greater the risk: HR: 7.66 [3.34-17.54] third versus first tertil. The cost directly attributable to catheter use was 563.31 euros/month. All poor prognosis groups showed lower albumin and hemoglobin levels, without differences in efficacy. CONCLUSION: Tunneled catheter use at any time is associated with an increased risk of death. This effect increases with the duration of catheterization, both circumstances are independent of patient comorbidity at time start of hemodialysis and implies a higher net cost.

[Cinacalcet in patients on peritoneal dialysis with moderate to severe hyperparathyroidism resistant to conventional treatment, a one-year, prospective study]. / Cinacalcet en pacientes en diálisis peritoneal con hiperparatiroidismo moderado-severo resistentes a tratamiento convencional. Estudio prospectivo a un año.

BACKGROUND: Cinacalcet has improved the management of hyperparathiroidism (HPTH) in hemodialysis. To our knowledge there are no specific studies on peritoneal dialysis (PD). AIM: The aim of the present study was to evaluate the efficacy of Cinacalcet on the achievement of optimal and suboptimal targets on treatment of hyperparathiroidism (HPTH) in PD patients. As secondary objectives we have studied the safety of treatment and estimate the mean time to reach these targets, and evaluate economic cost. METHODS: Eighteen patients undergoing more than 4 months on PD with a severe HPTH (PTH > 500 pg/ml) resistant to conventional treatment with diet, chelants and vitamin D were included in this prospective open-label study. We have used the targets of K/DOQITM-clinical guidelines as optimal target. We have selected as suboptimal targets: PTH < 350 pg/ml, phosphorus < 6 mg/dl and calcium < 10.4 mg/dl (only when simultaneous CaxP was under 55 mg2/dl2). Oral Cinacalcet was given with main meal in a single daily start dose of 30 mg and titrated thereafter monthly. We considered the first value on target as an event and used a Kaplan-Meyer survival analysis to estimate mean time to reach target. RESULTS: On inclusion all patients have at least two previous PTH values over 500 pg/ml, PTH mean 695,3 (SD 96) and they were on PD with an appropriate efficacy during a mean of 15.56 months (SD 0.78). Mean follow-up time under Cinacalcet treatment was 12 months. The percentage of patients with a PTH under 350 pg/ml was 66,7% on month 3, 60% on month 6 and 100% after 1 year. The percentage of patients that reach an aggregate of all suboptimal targets (PTH< 350 pg/ml and calcium < 10.4 mg/dl and phosphorus< 6 mg/dl and CaxP < 55 mg2/dl2) was 33.3% on month 6 and 66.7% after 1 year. The mean time to reach PTH target was 2.33 months with a 95% confident interval [1.35-3.32] and to reach the aggregate of all target was 16.94 months [11.38-22.5]. Cinacalcet has been well tolerated, we reduced the dose in a single patient due to secondary effects, but treatment was not discontinued in any case. CONCLUSION: In summary the addition of Cinacalcet to conventional treatment in PD patients with resistant HPTH has improved the achievement of targets, and has been reasonably safe in our patients.

[Prospective monitoring of vascular access in hemodialysis by means of a multidisciplinary team]. / Seguimiento prospectivo del acceso vascular en hemodialisis mediante un equipo multidisciplinar.

PURPOSE: Nowadays, expert guidelines recommend the monitoring programs of the vascular access (VA) by a multidisciplinary team. MATERIAL AND METHOD: We present the experience over the last five years, of a prospective VA surveillance by a multidisciplinary team. The quality indicators reached are described as the associated factors for survival of the new VA. RESULTS: Three hundred seventeen VA have been studied, 73% were arteriovenous fistulas(AVF) and the rest were polytetrafluoroethylene (PTFE) grafts at 282 patients. The main causes of dysfunctions were elevated dynamic venous pressure (42.5%) and the decreased blood flow (36.4%) with a 88% of positive predictive value. Over the 5 years there was 88 thrombosis (24 AVF and 64 PTFE grafts), that means a hazard thrombosis global rate of 0.15 access/year, which were distributed in 0.06 for AVF and 0.38 in PTFE grafts. Two hundred and one repairs of VA were done: 66.6% were elective repair after a proper review by the multidisciplinary team and the rest of them were done after the AV thrombosis happened. Urgent rescue surgeries were done in 76% of the thrombosis. 62.5% of the patients did not need a catheter after vascular access thrombosis. The complication relation with AVF and PTFE were 11.4% of the total patients hemodialysis hospitalizations. 65.2% of the VA were new access. 57% of patients were properly reviewed in the pre-dialysis unit at least once and 80% of them start haemodialysis with a mature access. The average survival (Kaplan Meier) of the new AVF was 1,575+/-55 days vs 1,087+/-102 of the PTFE grafts (p < 0.008). The survival after 1, 2 and 3 years for the AVF was 89%, 85% and 83% and for the PTFE graft 3% 67% and 51% respectively. The Cox regression has proved that the type of vascular access is the strongest factor associated to VA survival. The survival added of VA repaired due to dysfunction was 1,062 +/- 97 days vs 707 +/- 132 due to thrombosis, log rank 5.17 (p < 0,02). The increasing risk of those repaired after a thrombosis vs dysfunction is 4.2 p < 0,01. CONCLUSIONS: The monitoring of the vascular access by a multidisciplinary team has reached:low rate of thrombosis, high elective number of repairs of the VA, high urgent rescue surgery after a thrombosis and a few number catheter needed and hospitalizations. AVF are associated with greater survival than PTFE. The VA repair due to dysfunction vs thrombosis had a greater survival as well.

Nephroprotective effect of cilastatin in allogeneic bone marrow transplantation. Results from a retrospective analysis.

Cilastatin, an inhibitor of the tubular brush border enzyme dehydropeptidase-I, is added in a fixed combination to imipenem. Cilastatin has been demonstrated in different animal models and in one clinical trial, to reduce the nephrotoxicity associated with cyclosporin A. To evaluate a possible nephroprotective effect of cilastatin following allogeneic BMT we conducted a retrospective analysis of 104 patients transplanted in our BMT Unit from January 1991 to January 1995. Imipenem/cilastatin (I/C) was used in a non-randomized manner in 64 patients during this period. Acute renal failure (ARF) was diagnosed in 32 patients (30%). ARF was not associated with gender, sepsis, conditioning regimen, underlying disease, bilirubin, or age. VOD occurred in 12/32 (37.5%) of patients with ARF whereas it occurred in only 7/72 (9.7%) of patients without ARF (P < 0.0007). ARF was not correlated with use of aminoglycosides, vancomycin, ciprofloxacine, ceftazidime or amphotericin-B. However, 13 patients of 64 exposed to I/C (20.3%) developed ARF vs 19 of 40 patients (47.5%) who were not exposed to I/C (P < 0.003; OR 0.28). Stratified analysis and multiple logistic regression confirmed the I/C nephroprotective action. The mean cyclosporin A levels in the I/C group were significantly decreased (208.6 +/- 64.9) vs the non-I/C group (265 +/- 118). We conclude that these results suggest I/C may counteract acute cyclosporin A nephrotoxicity following BMT and further prospective clinical trials are needed to confirm if routine administration of cilastatine confers benefit in the BMT setting.

Plasma endothelin-1 levels after stem cell transplantation.

Acute renal failure and veno-occlusive disease of the liver are serious complications following stem cell transplantation (SCT) and contribute to the non-relapse mortality associated with this procedure. Endothelins, a family of vasoconstrictor peptides, may be involved in the pathogenesis of a variety of renal and hepatic diseases, including CsA-associated hypertension and the hepatorenal syndrome. In order to study the relevance of endothelins to SCT-related liver and kidney dysfunction, we determined endothelin-1 (ET-1) levels in plasma samples obtained from 65 patients (38 autologous, 27 allogeneic) 7 days before and 7, 14 and 28 days after SCT. A steady increase in plasma ET-1 was observed after SCT (5.36 pg/ml, 95% CI 4.30-6.43 on day +28 vs 3.82 pg/ml, 95% CI 3.21-4.43 on day -7; P = 0.020). No differences in ET-1 levels existed between autologous and allogeneic SCT recipients at any of the time points studied (P = 0.561). In addition, no significant differences were observed among patients with renal dysfunction vs those without (P = 0.187), nor in patient groups with or without hepatic dysfunction (P = 0.075). In conclusion, even though plasma ET-1 levels showed a steady increase following SCT, no correlation could be found with development of SCT-related kidney or liver dysfunction.

Influence of post haemodialysis sampling on Kt/V result.

The recommended Kt/V is 1.2. Unfortunately there is no written policy for nurses on the procedure for taking blood urea nitrogen samples post haemodialysis. The aim of this study was to establish the Kt/V variability of haemodialysis patients depending on the method of collection of post-haemodialysis blood urea nitrogen. Twenty-two patients were analysed. A Kt/V was performed every 15 days during a period of 2 months. It was taken five times on each patient: 30 minutes before the end of a haemodialysis session (Kt/V30), at the end of haemodialysis (Kt/V1), after slowing flows (50 ml/min) for 2 minutes (Kt/V2) and after the blood circuit had been returned to the patient at 5 and 15 minutes respectively. (Kt/V5, Kt/V15). The Kt/V results were: Kt/V1 1.23 +/- 0.2 Vs Kt/V2 1.14 +/- 0.19 (p < 0.003); Kt/V5- 1.05 +/- 0.19 (p < 0.002 Vs Kt/V2); Kt/V15 1 +/- 0.16 (p < 0.05 Vs Kt/V5); Kt/V30 1.12 +/- 0.21 (pNS Vs Kt/V2). In conclusion, there was a large variability in the Kt/V depending on the method of collection of the blood urea nitrogen sample post-haemodialysis.

[Hypophosphatemia in dialysis units]. / Hipofosforemia en unidades de diálisis crónica.

Hypophosphatemia (Hf) is infrequently reported in chronic hemodialysis patients. The objective of this report is to describe the incidence, etiology, symptoms and treatment of Hf in a Dialysis Unit (defined as phosphorus < 2.5 mg/dL). In a retrospective study over a period of three years, we identified 22 cases of Hf, occurring on 11 among 149 patients. A two-groups distribution was made: Group A, patients with more than one episode (n = 3, 14 episodes of Hf) and Group B, patients with only one isolated episode of Hf (n = 8, 8 episodes of Hf). Plasma Ca, P, Albumin and nPCR were significant lower in group A (p < 0.05). Only two patients of group B had symptoms. Cases of Hf were: Group A: low-protein diet and alcoholism, Group B: decreased dietary intake due to non-digestive problems (n = 2) or due to digestive problems plus antacids (n = 4), phos-phate binders (n = 1) and dietary phosphorus restriction (n = 1). Three patients had secondary hyperparathyroidism. Treatment consisted on oral supplementarion by diet and changes in oral calcium salts. Intravenous supplementation was required acutely to raise serum P in a patient with auricular fibrilation. Two group A patients who has plasma 1.25 vitamin D < 5 pg/mL received vitamin D, and the third oral supplements of P. In all the cases, Hf resolved with these measures. We concluded that Hf is not so infrequent in hemodialysis. In patients with low-protein diet and low vitamin D concentration, Hf can be sustained. On the other hand, a decreased dietary intake maintaining similar phosphate binder's supplementation is the most frequent cause of occasional and symptomatic Hf, even in patients with secondary hyperparathyroidism.

[Application of process management in nephrology. Hemodialysis process management]. / Aplicación de la gestión por procesos en nefrología. Gestión del proceso hemodiálisis.

Total Quality Management techniques have recently been introduced into clinical practice. We describe the application of process management to hemodialysis therapy in a Spanish public hospital. The "ownership" of the hemodialysis process and its limits have been defined. We present a flowchart with all the activities involved in the process and the task description. Monitoring indicators have been selected according to the recommendations of the US Committee on the National Report on Health Care Delivery. Data sources for indicators have also been described.

[Why do ambulatory hemodialysis patients go to hospital emergency services? / Por qué acuden los pacientes de hemodiálisis extrahospitalaria a los servicios de urgencia hospitalarios?

UNLABELLED: An important number of Hospital admissions (HA) occurs through Hospital Emergency Departments (HED). This is a indicator of quality and have to be lower than 50%. However there are almost no data available on the causes of emergency consultation by outpatient hemodialysis patients (HD). For this reason, we prospectively examined a population of 83 outpatient HD patients dialyzed in a peripheral unit under the surveillance of a University Hospital. OBJECTIVES: 1) To know the diagnosis of HED and days of hospitalization for which HD patients came to the HED in 1998. 2) To know the possible risk factors associated with the patients with frequent assistance in HED. 3) To compare the number and causes of emergency consultation in 1998 with a group of patients treated in the same Unit in 1991 (n = 39). RESULTS: The percentage of patients who used the HED in 1998 was 66.3% (55/83). The total number of emergency episodes in 1998 was 118 (mean of 55 patients 2.27 +/- 1.51). Fifty one percent of the emergency episodes were due to patients initiative. The 4 more frequent diagnoses of HED in 1998 were infectious, 19.5% (23/118); traumatologic emergencies, 15.3% (18/118); digestive disease 15.3% (18/118); relationed problem vascular access, 11.9% (14/118). Thirty percent (36/118) of the emergency consultations needed HA leading to a mean hospitalitation of 10.2 +/- 9.3 days. The infectious disease were the highest percentage of HA (36.1%) and the longest days of hospitalitation (12.7 +/- 11.2 days). The risk factors for repeated emergency consultation (more than 3 times) were: age (68.9 vs 61.4), lower hematocrit (31.6 vs 34.4%), lower hemoglobin (10.2 vs 11), high EPO dose (166.3 vs 109.7 unit/kg/week) and lower Kt/V (0.99 vs 1.11). If we compare these results with 1991 the percentage that used the HED was similar 66.2% (pNS); the number of emergency episodes was higher (mean 2.99 +/- 1.96) than 1998 (p < 0.006) and there are a significant differences in the diagnoses of HED between 1998 and 1991: acute pulmonary edema 1.7 vs 11.2% (p < 0.003); hiperkalemia 0.8 vs 7.9% (p < 0.009); gastrointestinal disease 15.3% vs 4.5% (p < 0.008) and infectious 19.5% vs 7.9% (p < 0.01). In conclusion our study provides data previously not available on the epidemiology of Emergency Consultation by outpatient HD patients treated in the same peripheral unit. The data obtained albeit limited because of the number provide information of potential protocol usefulness for the possible reduction in the frequency of Hospital Emergency Consultations by outpatient HD patients.

[Acute renal failure in the allogeneic transplantation of hemopoietic progenitors. The clinical characteristics in a series of 92 patients]. / Fracaso renal agudo en el trasplante alogénico de progenitores hemopoyéticos. Características clínicas en una serie de 92 pacientes.

BACKGROUND: Analysis of clinical characteristics of acute renal failure (ARF) after allogeneic bone marrow transplantation (BMT). PATIENTS AND METHODS: Analysis of 92 patients who developed ARF of 260 patients following BMT. RESULTS: ARF incidence was 35.4%. Sixty three percent of ARF occurred before day 20 after BMT. Duration of ARF was less of 10 days in 72.8%. ARF was non oliguric in the 80.4% of cases. Most common ARF etiologies were: multifactorial (37%), nephrotoxicity (NPH) (33.7%) and veno-occlusive disease of the liver (VOD) (14.1%). ARF secondary to VOD was the most severe: and the longest, where the secondary to NPH was less lever and shorter. Hemodialysis (HD) was necessary in 22.8% of ARF. Mortality in ARF group was 45.6%, higher in HD group (80.9%) than in non-HD group (35.2%) (p < 0.0002). CONCLUSIONS: ARF is a frequent complication following BMT. It occurs early, has short duration, is non oliguric, mainly hemodynamic and carries a whose prognosis.

Role of type of vascular access in erythropoietin and intravenous iron requirements in haemodialysis.

BACKGROUND: Recent data have suggested the existence of a relationship between the use of synthetic vascular accesses and increased erythropoietin (Epo) requirements. The present study aimed to evaluate the possible role of the type of vascular access in both Epo and intravenous (i.v.) iron requirements. METHODS: One-hundred-and-seven individuals without recognized causes of Epo resistance, 62 of them undergoing chronic haemodialysis through native arteriovenous fistulae (AVF) and 45 through PTFE grafts, were retrospectively studied (one-year follow-up). Sixty-nine patients, i.e. all but three with a PTFE graft and 27 with native AVF, were taking anti-platelet agents. Doses of i.v. iron and Epo and laboratory parameters were recorded. RESULTS: Erythropoietin and i.v. iron requirements were higher in the patients dialysed through PTFE grafts compared with those with native AVF (Epo: 103.8+/-58.4 vs 81.0+/-44.5 U/kg/week, P=0.025; i.v. iron: 178.9+/-111 vs. 125.9+/-96 mg/month, P=0.01). On a yearly basis, the difference in Epo dose represented a total of 94582+/-16789 U Epo/patient/year. Moreover, the patients with PTFE grafts received more red blood cell transfusions than patients with native AVF (P=0.021). No differences between laboratory, dialysis kinetics, demographic or comorbidity parameters were found. The type of vascular access was the best predictor of the requirement of > or =150 U/kg/week Epo (P=0.03). Even though the patients who received anti-platelet therapy required more i.v. iron (167.5+/-103.6 vs. 114.5+/-101.4 mg/month, P=0.008) but not more Epo (P=NS), the possibility of an accessory role of anti-platelet agents in the increased Epo requirements with PTFE grafts cannot be ruled out. CONCLUSIONS: The use of a PTFE graft and anti-platelet drugs represents a previously undescribed association related to higher Epo and i.v. iron requirements. The association described herein adds new arguments to the debate concerning the choice of vascular access in chronic haemodialysis patients.

Acute renal failure in patients following bone marrow transplantation: prevalence, risk factors and outcome.

To assess the prevalence, risk factors, clinical causes and outcome of acute renal failure (ARF) following bone marrow transplantation (BMT), a retrospective analysis of 275 patients was undertaken. ARF was diagnosed in 72 patients (26%) and occurred in 81.9% within the first month. The three main clinical causes were multifactorial (36%), nephrotoxic (29%), and veno-occlusive disease of the liver (VOD) 15%. The prevalence was higher in allogeneic BMT (36%) than in autologous BMT (6.5%). Risk factors related to the development of ARF wee preexisting VOD and age older than 25 years. Logistic regression in allogeneic BMT confirmed this association (VOD, odds ratio 3.8; age offer than 25, odds ratio 1.9). Underlying disease, graft-versus-host disease, sepsis, conditioning therapy, and sex were not associated with ARF. Seventeen cases of ARF required hemodialysis (24%) mainly in association with VOD (70.5%). The overall morality from ARF was 45.8%, the dialyzed group having the highest mortality (88%). Survival in the ARF group was continuously worse up to 3 months and the actuarial survival at 10 years was 29.7 versus 53.2%. We conclude that ARF is a common complication mainly in allogeneic BMT and carries a grave prognosis. VOD and age were risk factors for ARF.