Is it useful to increase dialysate flow rate to improve the delivered Kt?

BACKGROUND: Increasing dialysate flow rates (Qd) from 500 to 800 ml/min has been recommended to increase dialysis efficiency. A few publications show that increasing Qd no longer led to an increase in mass transfer area coefficient (KoA) or Kt/V measurement. Our objectives were: 1) Studying the effect in Kt of using a Qd of 400, 500, 700 ml/min and autoflow (AF) with different modern dialysers. 2) Comparing the effect on Kt of water consumption vs. dialysis time to obtain an individual objective of Kt (Ktobj) adjusted to body surface. METHODS: This is a prospective single-centre study with crossover design. Thirty-one patients were studied and six sessions with each Qd were performed. HD parameters were acquired directly from the monitor display: effective blood flow rate (Qbe), Qd, effective dialysis time (Te) and measured by conductivity monitoring, final Kt. RESULTS: We studied a total of 637 sessions: 178 with 500 ml/min, 173 with 700 ml/min, 160 with AF and 126 with 400 ml/min. Kt rose a 4% comparing 400 with 500 ml/min, and 3% comparing 500 with 700 ml/min. Ktobj was reached in 82.4, 88.2, 88.2 and 94.1% of patients with 400, AF, 500 and 700 ml/min, respectively. We did not find statistical differences between dialysers. The difference between programmed time and Te was 8' when Qd was 400 and 500 ml/min and 8.8' with Qd = 700 ml/min. Calculating an average time loss of eight minutes/session, we can say that a patient loses 24' weekly, 312' monthly and 62.4 hours yearly. Identical Kt could be obtained with Qd of 400 and 500 ml/min, increasing dialysis time 9.1' and saving 20% of dialysate. CONCLUSIONS: Our data suggest that increasing Qd over 400 ml/min for these dialysers offers a limited benefit. Increasing time is a better alternative with demonstrated benefits to the patient and also less water consumption.

Haemodialysis patients have worse postural balance with an associated risk of falls. / Los pacientes en hemodiálisis presentan peor equilibrio postural, que se relaciona con el riesgo de caídas.

INTRODUCTION: Postural balance is the result of a complex interaction of sensory input which keeps us upright. Haemodialysis patients have alterations which can lead to postural instability and a risk of falls. Our objective was to analyse postural stability and its relationship with the risk of falls in haemodialysis patients using a force platform. MATERIAL AND METHODS: This was a prospective cross-sectional study. Postural balance was recorded using a force platform in prevalent haemodialysis patients. We collected epidemiological, dialysis, analytical and treatment data. The incidence of falls was recorded over the 6 months following the tests. The postural stability analysis was performed with a portable strain gauge platform (AMTI AccuGait®) and a specific software unit for stabilometry (Balance Trainer® program). We measured 31 balance parameters; the balance variables used were: Area95; AreaEffect; VyMax; Xrange and Yrange. The stabilometry studies were performed in 3 situations: with eyes open; with eyes closed; and with the patient performing a simultaneous task. We performed one study at the start of the dialysis session, and a second study at the end. Stabilometry was measured in a control group under similar conditions. RESULTS: We studied 32 patients with a mean age of 68 years old; of this group, 20 subjects were male and 12 were female. Their mean weight was 74kg, with a mean BMI of 27.6kg/m2. In the controls, there were no significant differences in the stabilometry between the 3 situations studied. Both pre- and post-haemodialysis, patients with closed eyes showed greater imbalance, and there were significant differences with the other situations and controls. We found a significant increase in instability after the haemodialysis session, and greater instability in the 13 patients with diabetes (P<.05). The 4 patients with hyponatraemia (Na<136mmol/l) had worse balance in the simultaneous task situation (P=.038). Various drugs, such as insulin (P=.022), antiplatelet agents (P=.036) and beta-blockers (P=.029), were associated with imbalance. The 10 patients who suffered falls had greater imbalance, Yrange, Xrange, Area95 and AreaEffect, both pre- and post-haemodialysis (P<.05) than those without falls. CONCLUSIONS: Haemodialysis patients have alterations which can lead to postural instability and a risk of falls. Prevention programmes which include specific exercises to improve balance could be beneficial in reducing the risk of falls in this population.

Hypomagnesaemia in haemodialysis is associated with increased mortality risk: its relationship with dialysis fluid. / La hipomagnesemia en hemodiálisis se asocia a mayor riesgo de mortalidad: su relación con el líquido de diálisis.

Hypomagnesaemia in haemodialysis (HD) is associated with increased mortality risk: its relationship with dialysis fluid (DF). INTRODUCTION: 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. OBJECTIVE: To study magnesium concentrations in haemodialysis patients, their predictive mortality rate and what factors are associated with hypomagnesaemia and mortality in haemodialysis. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[High prevalence of asymptomatic COVID-19 in haemodialysis: learning day by day in the first month of the COVID-19 pandemic]. / Alta prevalencia de COVID-19 asintomático en hemodiálisis. Aprendiendo día a día el primer mes de pandemia de COVID-19.

Dialysis patients are a risk group for SARS-CoV-2 infection and possibly further complications, but we have little information. The aim of this paper is to describe the experience of the first month of the SARS-CoV-2 pandemic in a hospital haemodialysis (HD) unit serving the district of Madrid with the second highest incidence of COVID-19 (almost 1,000 patients in 100,000h). In the form of a diary, we present the actions undertaken, the incidence of COVID-19 in patients and health staff, some clinical characteristics and the results of screening all the patients in the unit. We started with 90 patients on HD: 37 (41.1%) had COVID-19, of whom 17 (45.9%) were diagnosed through symptoms detected in triage or during the session, and 15 (40.5%) through subsequent screening of those who, until that time, had not undergone SARS-CoV-2 PCR testing. Fever was the most frequent symptom, 50% had lymphopenia and 18.4% <95% O2 saturation. Sixteen (43.2%) patients required hospital admission and 6 (16.2%) died. We found a cluster of infection per shift and also among those using public transport. In terms of staff, of the 44 people involved, 15 (34%) had compatible symptoms, 4 (9%) were confirmed as SARS-CoV-2 PCR cases by occupational health, 9 (20%) required some period of sick leave, temporary disability to work (ILT), and 5 were considered likely cases. CONCLUSIONS: We detected a high prevalence of COVID-19 with a high percentage detected by screening; hence the need for proactive diagnosis to stop the pandemic. Most cases are managed as outpatients, however severe symptoms are also appearing and mortality to date is 16.2%. In terms of staff, 20% have required sick leave in relation to COVID-19.

Unlike Kt, high Kt/V is associated with greater mortality: The importance of low V. / El Kt/V alto, a diferencia del Kt, se asocia a mayor mortalidad: importancia de la V baja.

INTRODUCTION: Kt/V has been used as a synonym for haemodialysis dose. Patient survival improved with a Kt/V>1; this target was subsequently increased to 1.2 and 1.3. The HEMO study revealed no significant relationship between Kt/V and mortality. The relationship between Kt/V and mortality often shows a J-shaped curve. Is V the confounding factor in this relationship? The objective of this study is to determine the relationship between mortality and Kt/V, Kt and body water content (V) and lean mass (bioimpedance). METHODS: We studied a cohort of 127 prevalent haemodialysis patients, who we followed-up for an average of 36 months. Kt was determined by ionic dialysance, and V and nutrition parameters by bioimpedance. Kt/V, Kt corrected for body surface area (Kt/BSA) and target Kt/BSA were calculated. The mean data from 18,998 sessions were used as haemodialysis parameters, with a mean of 155 sessions per patient. RESULTS: Mean age was 70.4±15.3 years and 61% were male; 76 were dialysed via an arteriovenous fistula and 65 were on online haemodiafiltration. Weight was 70.6 (16.8)kg; BSA 1.8 (0.25) m2; total body water (V) 32.2 (7.41) l and lean mass index (LMI) 11.1 (2.7)kg/m2. Mean Kt/V was 1.84 (0.44); Kt 56.1 (7)l and Kt/BSA 52.8 (10.4)l. The mean target Kt/BSA was 49.7 (4.5)l. Mean Kt/BSA-target Kt/BSA +6.4 (7.0)l. Patients with a higher Kt/V had worse survival rates than others; with Kt this is not the case. Higher Kt/V values are due to a lower V, with poorer nutrition parameters. LMI and serum albumin were the parameters that best independently predicted the risk of death and are lower in patients with a higher Kt/V and lower V. CONCLUSION: Kt/V is not useful for determining dialysis doses in patients with low or reduced body water. Kt or the Kt/BSA are proposed as an alternative.

Follow a recipe to prescribe phosphate during hemodialysis. / Receta para prescribir fósforo durante hemodiálisis.

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.

Psychosocial factors and adherence to drug treatment in patients on chronic haemodialysis.

BACKGROUND: The daily pill burden in hemodialysis patients is one of the highest reported to date in any chronic disease. The adherence to prescribed treatment has implications on the quality of life, the survival of patients, and the economic cost of their treatment, this being a priority public health issue. OBJECTIVE: To evaluate the adherence to pharmacological treatment examining, among the possible causes of non-adherence, psychosocial factors such as depression, anxiety, cognitive impairment and social support. METHOD: Transversal-observational study of thirty five patients that suffer from chronic renal disease and who are on manteinance hemodialysis, evaluated by self-reported measures. RESULTS: Non-adherent patients have significant higher depression index than adherent patients. Anxiety, cognitive impairment and social support do not show a significant relation with the degree of adherence or compliance with farmacological treatment. CONCLUSIONS: These results suggest that psychological intervention in chronic haemodialysis patients with a severe depression index could increase the degree of fulfillment and general well-being of renal patients.

A comparison of the effectiveness of two online haemodiafiltration modalities: mixed versus post-dilution.

INTRODUCTION: Haemodiafiltration (HDF) with high reinfusion volumes is the most effective technique for clearing uraemic toxins. There are various modalities depending on the location where the replacement volume is administered in the extracorporeal circuit: pre-dilution, mixed or mid-dilution and post-dilution, in which the infusion is carried out pre-dilution, pre- and post-dilution simultaneously and post-dilution, respectively. OBJECTIVE: Compare the clearance of small, medium-sized and protein-bound molecules and the convective volume administered in online HDF (OL-HDF) in post-dilution and mixed (pre-post-dilution) infusion. MATERIAL AND METHOD: A prospective, randomised, crossover study comparing post-dilution and mixed OL-HDF. Patients (n=8) were randomly assigned to receive 6 sessions in each technique. We conducted 89 sessions, of which 68 were at a scheduled time (ST) and 21 at an effective time (ET). We determined the reduction rate (RR) percentages for various substances and the infusion volumes. The RR study was performed using ET. RESULTS: The KT value obtained was greater with post-dilution OL-HDF [68 (8.1) compared to 64.9 (8.8) litres] (P=.009) when patients were dialysed at ST. This difference disappeared when dialysis was performed at ET. The difference between ST and ET was greater in mixed HDF than in post-dilution HDF [10.3 (7.4) compared to 6.5 (3.1) minutes, P=.02]. We found no differences in the RR of the substances analysed. CONCLUSION: Mixed OL-HDF is not inferior to post-dilution OL-HDF either in the clearance of small and medium-sized molecules or in the clearance of protein-bound molecules at the same ET.