BACKGROUND: Acute kidney injury (AKI) is common among hospitalized patients with COVID-19 and associated with worse prognosis. The Spanish Society of Nephrology created the AKI- COVID Registry to characterize the population admitted for COVID-19 that developed AKI in Spanish hospitals. The need of renal replacement therapy (RRT) therapeutic modalities, and mortality in these patients were assessed MATERIAL AND METHOD: In a retrospective study, we analyzed data from the AKI-COVID Registry, which included patients hospitalized in 30 Spanish hospitals from May 2020 to November 2021. Clinical and demographic variables, factors related to the severity of COVID-19 and AKI, and survival data were recorded. A multivariate regression analysis was performed to study factors related to RRT and mortality.
RESULTS: Data from 730 patients were recorded. A total of 71.9% were men, with a mean age of 70 years (60-78), 70.1% were hypertensive, 32.9% diabetic, 33.3% with cardiovascular disease and 23.9% had some degree of chronic kidney disease (CKD). Pneumonia was diagnosed in 94.6%, requiring ventilatory support in 54.2% and admission to the ICU in 44.1% of cases. The median time from the onset of COVID-19 symptoms to the appearance of AKI (37.1% KDIGO I, 18.3% KDIGO II, 44.6% KDIGO III) was 6 days (4-10). A total of 235 (33.9%) patients required RRT: 155 patients with continuous renal replacement therapy, 89 alternate-day dialysis, 36 daily dialysis, 24 extended hemodialysis and 17 patients with hemodiafiltration. Smoking habit (OR 3.41), ventilatory support (OR 20.2), maximum creatinine value (OR 2.41), and time to AKI onset (OR 1.13) were predictors of the need for RRT; age was a protective factor (0.95). The group without RRT was characterized by older age, less severe AKI, and shorter kidney injury onset and recovery time (p < 0.05). 38.6% of patients died during hospitalization; serious AKI and RRT were more frequent in the death group. In the multivariate analysis, age (OR 1.03), previous chronic kidney disease (OR 2.21), development of pneumonia (OR 2.89), ventilatory support (OR 3.34) and RRT (OR 2.28) were predictors of mortality while chronic treatment with ARBs was identified as a protective factor (OR 0.55).
CONCLUSIONS: Patients with AKI during hospitalization for COVID-19 had a high mean age, comorbidities and severe infection. We defined two different clinical patterns: an AKI of early onset, in older patients that resolves in a few days without the need for RRT; and another more severe pattern, with greater need for RRT, and late onset, which was related to greater severity of the infectious disease. The severity of the infection, age and the presence of CKD prior to admission were identified as a risk factors for mortality in these patients. In addition chronic treatment with ARBs was identified as a protective factor for mortality.

Chronic kidney disease-associated pruritus (CKD-aP) is one of the most common and disabling comorbidities in patients with advanced CKD. In addition, it is associated with an increased risk of mortality, poorer quality of life, sleep disorders, mental health disorders, and increased use of health care resources. The clinical presentation of CKD-aP is very heterogeneous, making it difficult to diagnose and treat. Currently, there are no national guidelines on the management of CKD-aP. The aim of this document is to provide national consensus recommendations for the diagnostic and therapeutic management of CKD-aP. The document was prepared in three phases: a diagnostic and therapeutic management algorithm was proposed by a small group of nephrology specialists; the proposal was validated by a larger group of nephrologists; and a second validation by a multidisciplinary group that also included dermatology specialists. The diagnostic and therapeutic management algorithm attempts to cover the current need of a lack of specific guidelines for the adequate management of CKD-aP. At the same time, it introduces the use of difelikefalin, the first and only drug specifically approved for CKD-aP, with a good safety and efficacy profile.

BACKGROUND: The influence of socioeconomic and cultural barriers in the choice of renal replacement therapy (RRT) techniques in advanced chronic kidney disease (ACKD) has been scarcely explored, which can generate problems of inequity, frequently unnoticed in health care. The aim of this study is to identify the \"non-medical\" barriers that influence the choice of RRT in an advanced chronic kidney disease (ACKD) consultation in Spain.
METHODS: Retrospective analysis including the total number of patients seen in the ACKD consultation in a tertiary hospital from 2009 to 2020. Inclusion in the ACKD consultation began with an eligibility test and a decision-making process, conducted by a specifically trained nurse. The variables considered for the study were: age, sex, etiology of CKD, level of dependence for basic activities of daily living (Barthel Scale) and instrumental activities of daily living (Lawton and Brody Scale), Spanish versus foreign nationality, socioeconomic level and language barrier. The socioeconomic level was extrapolated according to home and health district by primary care center to which the patients belonged.
RESULTS: A total of 673 persons were seen in the ACKD consultation during the study period, of whom 400 (59.4%) opted for hemodialysis (HD), 156 (23.1%) for peritoneal dialysis (PD), 4 (0.5%) for early living donor renal transplantation (LDRT) and 113 (16.7%) chose conservative care (CC). The choice of PD as the chosen RRT technique (vs. HD) was associated with people with a high socioeconomic level (38.7% vs. 22.5%) (p = 0.002), Spanish nationality (91% vs. 77.7%) (p < 0.001), to a lower language barrier (0.6% vs 10.5%) (p < 0.001), and to a higher score on the Barthel scale (97.4 vs 92.9) and on the Lawton and Brody scale (7 vs 6.1) (p < 0.001). Neither age nor sex showed significant differences in the choice of both techniques. Patients who opted for CC were significantly older (81.1 vs 67.7 years; p < 0.001), more dependent (p < 0.001), with a higher proportion of women (49.6% vs 35.2%; p = 0.006) and a higher proportion of Spaniards (94.7% vs 81%, p = 0.001) in relation to the choice of other techniques (PD and HD). Socioeconomic level did not influence the choice of CC.
CONCLUSIONS: Despite a regulated decision-making process, there are factors such as socioeconomic status, migration, language barrier and dependency of the population that influence the type of RRT chosen. To address these aspects that may cause inequity, an intersectoral and multilevel intervention is required with interdisciplinary teams that include, among others, social workers, to provide a more holistic and person-centered assessment.

Sarcopenia and dynapenia are two terms associated with ageing that respectively define the loss of muscle mass and strength. In 2018, the European Working Group on Sarcopenia in Older People (EWGSOP) introduced the EWGSOP2 diagnostic algorithm for sarcopenia, which integrates both concepts. It consists of 4 sequential steps: screening for sarcopenia, examination of muscle strength, assessment of muscle mass and physical performance; depending on these last 3 aspects sarcopenia is categorised as probable, confirmed, and severe respectively. In the absence of validation of the EWGSOP2 algorithm in various clinical contexts, its use in haemodialysis poses several limitations: (a) low sensitivity of the screening, (b) the techniques that assess muscle mass are not very accessible, reliable, or safe in routine clinical care, (c) the sequential use of the magnitudes that assess dynapenia and muscle mass do not seem to adequately reflect the muscular pathology of the elderly person on dialysis. We reflect on the definition of sarcopenia and the use of more precise terms such as \"myopenia\" (replacing the classic concept of sarcopenia to designate loss of muscle mass), dynapenia and kratopenia. Prospective evaluation of EWGSOP2 and its comparison with alternatives (i.e. assessment of kratopenia and dynapenia only; steps 2 and 4) is proposed in terms of its applicability in clinical routine, resource consumption, identification of at-risk individuals and impact on events.

BACKGROUND: Changes in plasma sodium concentration (pNa, expressed in mEq/L) are common in hemodialysis (HD) patients. Hemodialysis monitors can estimate pNa by using an internal algorithm based on ion dialysance measurements. The present study studies the accuracy of the correlation between the pNa estimated by the dialysis monitor and that measured by the biochemistry laboratory at our center.
METHODS: A single-centre prospective observational study in patients on a chronic HD program with the 6008 CAREsystem monitor and standard sodium (138mmol/L) and bicarbonate (32mmol/L) prescriptions. Venous blood samples were drawn from each patient before and after each HD session to ensure inter- and intra-individual validity. The pNa was measured in the biochemistry laboratory using indirect potentiometry and simultaneously the estimated pNa by the HD monitor was recorded at the beginning and at the end of the HD session. For statistical analysis, a scatterplot was made, and Spearman\'s correlation quotient was calculated. In addition, the differences between both methods were represented as Bland-Altman diagrams.
RESULTS: The pre-dialysis pNa measured in the laboratory was 137.49±3.3, and that of the monitor, 137.96±2.91, with a correlation with R2 value of 0.683 (p<0.001). The post-dialysis pNa measured in the laboratory was 137.08±2.23, and that of the monitor was 138.87±1.88, with an R2 of 0.442 (p<0.001). On the Bland-Altman plots, the pre-dialysis pNa has a systematic error of 0.49, in favor of the monitor-estimated pNa, with a 95% confidence interval (CI) of (-3.24 to a 4.22). In the post-dialysis pNa, a systematic error of 1.79 with a 95% CI of (-1.64 to 5.22) was obtained.
CONCLUSIONS: The correlation between the pNa estimated by Fresnius 6008 CAREsystem HD monitor and that measured by the laboratory is good, especially pre-dialysis measurements. Further studies should verify the external validity of these results.

OBJECTIVE: Patient activation is a concept that refers to the willingness to manage one\'s health and medical care. To assess it, a patient activation measure (PAM) has been developed and validated. Several studies report low activation in patients with chronic diseases. However, information on activation in hemodialysis patients is scarce. The aim of the present study is to describe the activation level of patients on chronic treatment in an HD unit and its relationship with disease control parameters.
METHODS: Cross-sectional observational study in patients with advanced chronic kidney disease on chronic HD treatment. Ninety-six patients were included. Activation was measured with the PAM-13 questionnaire. Its relationship with descriptive variables (age, sex, comorbidity, studies, habitat) and disease control variables (vascular access, blood flow, potassaemia, phosphataemia, interdialytic gain) was studied. For this purpose, Spearman\'s correlation test, multiple linear regression model and logistic model were used as statistical methods.
RESULTS: The mean (SD) PAM-13 score was 63.19 (15.21). Activation was significantly associated with vascular access (P = 0.003), blood flow (P = 0.024), and interdialytic gain of patients (P = 0.008).
CONCLUSIONS: Activation in patients on chronic hemodialysis treatment is low. Higher activation is related having an arteriovenous fistula, higher blood flow and lower interdialytic gain. Future studies are needed to confirm and apply our results.

We discuss two recent cases from our hospital in which two patients with ESKD receiving periodical hemodialysis (HD) and SarS-Cov-2 infection suffered movement disorders, being the onset related to the HD sessions in both. First case is a 78 year-old woman who is admitted with generalized myoclonic status epilepticus and second case is a 46 year-old male who starts repeatedly suffering myoclonus during his hemodialysis sessions on day +10 after testing positive (asymptomatic infection). There are two main hypotheses when it comes to myoclonus and CNS disorders in COVID19, post-hypoxic origin and inmunomediated postinfectious origin. We wonder if they could both be interacting in patients with kidney disease, and especially in those who receive hemodialysis, maximizing the risk of suffering this type of disorders.

Anemia is a common condition in end-stage renal disease (ESRD) patients. Erythropoiesis-stimulating agents (ESAs) are commonly used to treat anemia in these patients. However, concerns have been raised regarding their potential effects on blood pressure. This systematic review and meta-analysis aim to investigate the relationship between ESAs and changes in systolic and diastolic blood pressure in hemodialysis patients.
This study is a systematic review and meta-analysis based on clinical trial studies published in various databases, including Web of Science, Cochrane Library, Science Direct, PubMed, Embase, Scopus, and Google Scholar, between 1980 and the end of 2022. We evaluated the quality of articles using the Jadad scale checklist and analyzed the data using Stata 15 software.
Our meta-analysis included 34 clinical trial studies. The results showed a significant increase in both systolic blood pressure (SBP) and diastolic blood pressure (DBP) after the consumption of ESAs compared to before consumption. The mean difference in SBP was 4.84mmHg (95% CI: 2.74-6.94; p-value<0.001) and in DBP was 4.69mmHg (95% CI: 2.67-6.71; p-value<0.001). No publication bias was observed. Our meta-regression analysis showed that sample size, quality assessment score, and geographical location of the study were significant factors related to observed heterogenicity in to mean difference of SBP (p-value≤0.20). For DBP, the sample size, quality assessment score and follow-up duration were significant variables (p-value≤0.20).
Based on the findings of our study, it appears that receiving ESAs is associated with a significant increase in both SBP and DBP in hemodialysis patients, with an increase of about 5mmHg.

The sodium gradient during hemodialysis sessions is one of the key factors in sodium balance in patients with dialysis-dependent chronic kidney disease; however, until the appearance of the new monitors with sodium modules, the differences between prescribed and measured sodium have been understudied. The present study aimed to compare the impact on the measured conductivity and the initial and final plasma sodium after changing the 5008 Cordiax to the new 6008 Cordiax monitor.
106 patients on hemodialysis were included. Each patient underwent 2 dialysis sessions in which only the monitor was varied. The variables collected were dialysate, sodium and bicarbonate prescribed, real conductivity, initial and final plasma sodium measured, and the calculated sodium gradient (ΔPNa).
The change of dialysis monitor showed small but statistically significant differences in the initial (138.14mmol/L with 5008 vs. 138.81mmol/L with 6008) and final plasma sodium (139.58mmol/L vs. 140.97mmol/L), as well as in the actual conductivity obtained (13.97 vs. 14.1mS/cm). The ΔPNa also increased significantly.
The change from 5008 to 6008 monitor is associated with increased conductivity, leading the patient to end the sessions with higher plasma sodium and ΔPNa. Knowing and confirming this change will allow us to individualize the sodium prescription and avoid possible undesirable effects. It could be the preliminary study to explore the new sodium biosensor incorporated into the new generation of monitors.

Hemodiafiltration with endogenous reinfusion of the ultrafiltrate (HFR) is a dialysis technique characterized by a resin cartridge with adsorptive properties that combines the mechanisms of diffusion, convection, and adsorption in a single therapeutic regimen. After nearly 20 years of clinical experience with HFR, this article reviews the accumulated evidence with this technique, considering whether adsorption reduction, as a third purification mechanism, should be the next step in the treatment of hemodialysis patients. HFR, beyond producing an extensive removal of uremic toxins, has demonstrated to reduce the loss of nutrients and other physiological components during the dialysis session as compared to online hemodiafiltration, ameliorating the inflammatory state and oxidative stress in this population. In addition to its ease of use, the technique is also highly biocompatible and can be used in patients with a compromised vascular access. Based on these observations, HFR appears to be an especially useful therapy for high-comorbidity patients, including those with frailty, malnutrition, or cardiovascular disease. In this review, we, as a consensus panel of nephrologists experienced with HFR, survey existing literature and summarize our views on when to use this technique, which patients may be best suited for HFR, and how to effectively prescribe and monitor this modality of dialysis in daily clinical practice.