Hemodialysis (HD) with bicarbonate dialysis fluid (DF) requires the presence of an acid to prevent the precipitation of calcium and magnesium carbonate. The most used acid is acetic acid, with it several complications have been described. In a previous work we described the acute changes during an HD session with a DF with citrate instead of acetate. Now we report the results in the medium term, 16 weeks. It is a prospective, multicenter, crossover and randomized study, where 56 HD patients with bicarbonate three times a week were dialysed for 16 weeks with 3 mmol/L acetate and 16 weeks with 1 mmol/L citrate. Patients older than 18 years with a previous stay on HD of more than 3 months and with a normal functioning arteriovenous fistula were included. Epidemiological data, dialysis, bioimpedance, biochemistry before and after HD, as well as hypotensive episodes, were collected monthly. After 16 weeks of citrate treatment, preHD ionic calcium and magnesium were significantly lower and PTH higher than in the acetate period. No differences were observed in the effectiveness of dialysis. Hypotensive episodes were significantly more frequent with acetate than with citrate: 311 (14.1%) vs 238 (10.8%) sessions. The lean mass index increased by 0.96 ± 2.33 kg/m2 when patients switched from LD with acetate to citrate. HD with citrate modifies several parameters of bone mineral metabolism, not only acutely as previously described, but also in the long term. The substitution of acetate for citrate improves hemodynamic stability, producing less hypotension and can improve nutritional status.

Hemodialysis (HD) with bicarbonate dialysis fluid (DF) requires the presence of an acid to prevent the precipitation of calcium and magnesium carbonate. The most used acid is acetic acid, with it several complications have been described. In a previous work, we described the acute changes during an HD session with a DF with citrate instead of acetate. Now, we report the results in the medium term, 16 weeks. It is a prospective, multicenter, crossover and randomized study, where 56 HD patients with bicarbonate three times a week were dialysed for 16 weeks with 3mmol/L acetate and 16 weeks with 1mmol/L citrate. Patients older than 18 years with a previous stay on HD of more than 3 months and with a normal functioning arteriovenous fistula were included. Epidemiological data, dialysis, bioimpedance, biochemistry before and after HD, as well as hypotensive episodes, were collected monthly. After 16 weeks of citrate treatment, pre-HD ionic calcium and magnesium were significantly lower and paratiroid hormone (PTH) higher than in the acetate period. No differences were observed in the effectiveness of dialysis. Hypotensive episodes were significantly more frequent with acetate than with citrate: 311 (14.1%) vs 238 (10.8%) sessions. The lean mass index increased by 0.96±2.33kg/m2 when patients switched from DF with acetate to citrate. HD with citrate modifies several parameters of bone mineral metabolism, not only acutely as previously described, but also in the long-term. The substitution of acetate for citrate improves hemodynamic stability, producing less hypotension and can improve nutritional status.

Hypomagnesaemia in haemodialysis (HD) is associated with increased mortality risk: its relationship with dialysis fluid (DF).
Low concentrations of magnesium (Mg) in blood have been linked to the development of diabetes, hypertension, arrhythmias, vascular calcifications and an increased risk of death in the general population and in haemodialysis patients. The composition of the dialysis fluid in terms of its magnesium concentration is one of the main determinants of magnesium in haemodialysis patients.
To study magnesium concentrations in haemodialysis patients, their predictive mortality rate and what factors are associated with hypomagnesaemia and mortality in haemodialysis.
Retrospective study of a cohort of prevalent haemodialysis patients followed up for two years. Serum magnesium was measured every six months. The analysis used the initial and average magnesium values for each patient, comparing patients with magnesium below the mean (2.1mg/dl) with those with magnesium above the mean. During the follow-up, three types of dialysis fluid were used: type 1, magnesium 0.5 mmol/l; type 3, magnesium 0.37 mmol/l (both with acetate); and type 2, magnesium 0.5 mmol/l with citrate.
We included 137 haemodialysis patients in the study, of which 72 were male and 65 were female, with a mean age of 67 (15) [26-95] years old. Of this group, 57 patients were diabetic, 70 were on online haemodiafiltration (OL-HDF) and 67 were on high-flow haemodialysis (HF-HD). The mean magnesium of the 93 patients with dialysis fluid type 1 was 2.18 (0.37) mg/dl. In the 27 patients with dialysis fluid type 3 it was 2.02 (0.42) mg/dl. And in the 17 with dialysis fluid type 2 it was 1.84 (0.24) mg/dl (p=.01). There was a pronounced direct relationship between Mg and P and albumin. After a mean follow-up of 16.6 (8.9) [3-24] months, 77 remained active, 24 had died and 36 had been transplanted or transferred. Patients with magnesium above than 2.1mg/dl had a longer survival (p=.008). The survival of patients with the three types of dialysis fluid did not differ significantly (Log-Rank, p=.424). Corrected for blood magnesium, patients with dialysis fluid with citrate have better survival (p=.009). The COX regression analysis shows how age, serum albumin, magnesium, dialysis technique and type of dialysis fluid have an independent predictive mortality rate.
Low serum magnesium levels have a greater association with an increased risk of mortality compared to high levels. The type of dialysis fluid affects the magnesium concentration and the risk of death.

Hypertension is a highly prevalent disorder among patients undergoing haemodialysis. It contributes to greater cardiovascular risk and must be controlled. However, despite dietary measures, haemodialysis regimen optimisation and pharmacological treatment, some patients in our units continue to maintain high blood pressure levels. The objective of the study is to demonstrate that reducing calcium in dialysis fluid can help treat hypertension patients undergoing haemodialysis.
We selected all of the hypertensive patients from our haemodialysis unit. We checked their normovolemic status by means of bioimpedance spectroscopy, decreasing the haemodialysis fluid\'s calcium concentration to 2.5mEq/l, with a follow-up period of 12 months.
A total of 24 patients met the non-volume dependent hypertension criteria (age 61±15 years, males 48%, diabetes 43%). A significant systolic and diastolic blood pressure decrease was observed at 6 and 12 months as a result of reducing the dialysis calcium concentration; this was not accompanied by greater haemodynamic instability (baseline systolic blood pressure: 162±14 mmHg; at 6 months: 146±18 mmHg; at 12 months: 141±21 mmHg; P=.001) (baseline diastolic blood pressure: 76±14 mmHg; at 6 months: 70±12 mmHg; at 12 months: 65±11 mmHg; P=.005). A non-significant increase in plasma parathyroid hormone levels was also found. No side effects were observed.
Adding 2.5mEq/l of calcium to dialysis fluid is a safe and effective therapeutic alternative to control hard-to-manage hypertension among haemodialysis patients.

The addition of phosphorus (P) to the dialysate (LD) in the form of enema Casen® is common practice in patients with hypophosphatemia. The estimation of the amount to be used and the identification of the problems that may can occur are not well defined. As a result of our work we propose a practical approach of how to proceed to increase phosphate concentration in the hemodialysate. We present a reasoned formula to calculate how much enema has to be added and the problems that may arise.

A Best Practice Guideline about Dialysis fluid purity was developed under the leadership of the Spanish Society of Nephrology in 2004. The second edition revised Guideline considered new evidences and International Standard. The Guideline has established recommendations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. This Guideline is based on the ISO13959, European Pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, European Best Practice Guidelines for Haemodialysis, literature reviews, according to their level of evidence, and the opinion of the expert Spanish group. Two levels of quality of water were defined: purified water and high purified water (ultra pure) and for dialysate: ultra pure dialysate. Regular use of ultra pure dialysate is recommended for all type of hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anaemia and amiloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowable contaminant levels: chemicals (4.1.2), conductivity, microbial and endotoxins (4.1.1): Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (anexos). For microbiological monitoring, R2A medium is recommended, incubated during 7-14 days at a temperature of 17-23°C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality. All suggestions and questions about this Guideline are wellcome to www.senefro.org.