BACKGROUND AND AIMS Acute kidney injury (AKI) is a common complication among patients hospitalized with COVID-19. The incidence of AKI is estimated to be around 5%–80%, according to the series, but data on renal function evolution is limited. Our main objective was to describe the incidence of AKI in patients with SARS-CoV-2 infection; secondarily, we analysed the severity of AKI and medium-term renal function evolution in these patients. METHOD A retrospective observational study that included patients hospitalized a single hospital, diagnosed with SARS-CoV-2 infection, who developed AKI (March-May 2020). We register clinical and demographic characteristics, creatinine upon admission and prior to discharge, as well as creatinine and CKD-EPI glomerular filtration rate (eGFR) after at least 3 months after discharge. CKD was defined according to KDIGO stages based on the eGFR (G3-G5). The KDIGO classification was used to define and classify AKI. Recovery of kidney function was defined as difference in at discharge or post-hospitalization creatinine < 0.3 mg/dL with respect basal creatinine. The clinical follow-up ranged from admission to death or end of study. RESULTS Of 258 patients hospitalized with SARS-CoV-2 infection, AKI occurred in 73 (28.3%). 63% (n = 46) were men; the mean of age was 69 years (57–76). DRA severity: 35 (48%) KDIGO-1, 15 (21%) KDIGO-2 and 23 (31%) KDIGO-3. The mean stay was associated with the severity of AKI: 7 days (3–11) for KDIGO-1, 11 days for KDIGO-2 (5–22) and 12 days (8–35) for KDIGO-3 (P = .02). The stage of CKD established differences in the severity of AKI: 66.6% (n = 6) of the patients with CKD G4–G5 presented AKI-KDIGO 3 versus only 25.0% (n = 4) in the CKD-G3 patients (P = .02). Admission to the ICU was more frequent in KDIGO 2–3 versus KDIGO-1 [39% (n = 15) versus 9% (n = 3); P < .01]. Of the 48 patients discharged, 30 (62.5%) had recovered their baseline renal function upon discharge. Only 2 are still on RRT after 8 months (2.7% of all patients). Of the 25 patients died (34% of patients with AKI) with a median time of 3 days from DRA diagnosis (1–8). Renal function of 35 patients was monitored, which correspond to 19 (54%) KDIGO-1, 8 (23%) KDIGO-2, 8 (23%) KDIGO-3 stages. In these patients, analytical control starting 3 months after hospitalization revealed FG 66 (SD 30; 56–76) mL/min/1.73 m2. We have not found differences in renal function between pre- and post-hospitalization in related test. A total of 77% (n = 37) of discharged patients recovered their baseline renal function in the post-hospitalization control. CONCLUSION The incidence of AKI in the context of COVID-19 in our series was 28.3%, with an associated mortality of 34.2%. Most of the patients presented with AKI KDIGO 1 (47.9%). The severity of AKI is associated with a longer hospital stay, admission to the ICU and the requirement for RRT. The advanced stages of CKD pre-admission showed more severity of AKI. The maintenance in TRS in our series has been 2.7%. Patients who were discharged for recovery/improvement of COVID-19 had normalized kidney function during subsequent follow-up, regardless of the severity of the AKI developed on admission for COVID-19.

Background and Aims Kidney injury is a common complication in multiple myeloma (MM) and it has a negative prognostic implication. Most common cause of Acute Kidney Injury (AKI) in these patients is Light chain Cast Nephropathy, where free light chains precipitate in the tubules and bind with uromodulin, turning into intratubular casts that obstruct the tubules and also promote local giant cell reaction and interstitial inflammation and fibrosis. Free light chains (FLCs) can also damage the kidneys due to direct tubular toxicity when excessive amounts are reabsorbed by the proximal tubules. Targeted therapy to reduce FLC load can help recover renal function. Both total reduction and reduction speed are relevant for prognosis. FLC removal through extracorporeal techniques can be used as an adjuvant therapy, having an important part on the evolution of the disease. We gathered data from our experience treating MM patients with AKI with HFR-supra hemodialysis (HD) and analized the evolution and possible influence of this technique on renal recovery. Method This is an observational retrospective study. We included all patients with a diagnosis of multiple myeloma and acute kidney injury who received HFR-Supra hemodialysis in between years 2016-2022 in Hospital Virgen Macarena (Seville). We initially performed 6-10 daily HFR-Supra HD sessions and then modulated the frequency based on renal response (if renal replacement therapy had to be continued they underwent a usual hemodialysis regime 3 days a week). We continued these sessions until renal recovery was achieved or free light chain levels were reduced in agreement with the Hematology team. Measurement of pre and post dialysis FLCs was made always at first and last session and at least once in between, depending on the total number of sessions. Results 12 patients, with mean age at diagnosis 63.6 (43-86) years, presented with AKI stage KDIGO 3. 1 of them was oliguric. Median serum creatinine at diagnosis was 4.4 mg/dL [2,2-17], mean proteinuria was 4,1g/24 h [0,7-8,7] and 66,7% had positive Bence Jones proteinuria (mean 2,3g/24 h). 2 of the patients had previous chronic kidney disease stage 3a. All of them were diagnosed with Light Chain Multiple Myeloma (75% kappa, mean 10346 mg/L; 25% lambda, mean 5990 mg/L). Mean clonal bone marrow plasma cell was 20,7% [2-55]. According to the Revised International Staging System (R-ISS), 25% were stage 2 and 75% were stage 3. Renal biopsy was performed in 4 patients, all showed evidence of Cast Nephropathy. The indication for starting HFR-Supra HD was FLC removal in 9 patients, need of renal replacement therapy in 1 and both in 2 patients. We have experience in our center with using this therapy as an adyuvant treatment and often we start the technique in patients who present with AKI but would not necessarily have immediate need for renal replacement therapy. The goal is to remove FLCs and avoid further damage to the kidney tissue. Out of the 12 patients, 9 were able so stop dialysis (75%). They received a mean number of 12,4 [3-41] sessions in 3,7 [0,2-25] months). Free light chain removal per session was 24% on average [5-43%]. All of them were started on bortezomib-dexamethasone regime as initial chemotherapy for MM. As per renal recovery, at 3 months 33,3% achieved complete response, 11,1% partial response and 55,6% minimal response. At 1 year, 42,9% achieved complete response, 14,3% partial response and 42,9% minimal response. One-year survival rate was 91,7% (1 patient died from respiratory sepsis less than 1 month after diagnosis). Conclusion HFR-Supra hemodialyisis achieved a 24% free light chain removal per session on average. After presenting severe AKI (KDIGO 3), almost 43% of patients who received this adyuvant therapy obtained full renal recovery at 1 year and in 75% of patients withdrawal from hemodialysis was possible. 1 year survival was 91,7%.

Background and Aims Tunneled catheter-related bacteremia (TCRB) is a common and severe cause of bacteremia among hemodialysis (HD)-dependent patients. TCRB have reported incidence of 0.5 to 5.5 events per 1000 catheter days and are associated with increased morbidity and death. The main objetive of our study is determinate the incidence of TCRB in our hospital and, secondarily, to analyze our microbiology, recurrence and reinfection rates. Method The study is an observational retrospective evaluation of medical records of patients in whom a TC for HD was implanted in the period from January 1, 2005, to December 31, 2018. The TC were implanted by nephrologists, following a preimplantation and management protocol agreed with the Infectious Diseases Unit. Patients were followed up from TC insertion until the study end date or first of recovery kidney function, kidney transplantation, transition to peritoneal dialysis or death. CRB definition was according Spanish Clinical Guidelines on Vascular Access for Haemodialysis: positive blood culture accompanied by fever or clinical signs of sepsis, without another posible site of infection. We recorded demographic, clinical and TC-related variables (conditions of catheter insertion, site of catheter insertion and duration of use, etc.). Exclusion criteria for our study were the lack of clinical follow-up due to belonging to a different hospital area. Results A total of 393 TC were implantated over a period of 13 years. After applying exclusion criteria, we investigated 341 TC implanted in 279 patients: 265 into the intern jugular vein, 71 into the subclavian and 5 in femoral vein. The mean age of the included patients was 63 (range 19-93 years). Fifty-one percent of catheter was implanted in male patients. Forty-six percent of the patients suffered from diabetes mellitus. In 55% of the cases, the cause of CT implantation was the difficulty of creating an internal vascular access. In total there were 91 CRB in 58 patients, with a rate of 0.48 infections per 1000 catheter days (figure 1), occurring at median 461 days (range 143-443 days) after catheter insertion. Within that group, 82.4% occurred after 6 months from the implementation of the CPT. Only 6 (6.59%) took place in the 30 days after implantation. Gram-positive organisms accounted of 85%, with a predominance of Staphylococcus epidermidis (47%) followed by Staphylococcus aureus (25%). A broad spectrum of Gram-negative bacteria accounts for 14% of patients. Nineteen TC were removed by CRB, with a rate of 5.5% of total functioning TC. CRB was the cause of death in 7 of the 279 patients (2.5%). During the study, 12 (13% of CRB) recurrences and 30 (32% of CRB) reinfections events have been identified. Conclusion The incidence of CRB in our population was found to be lower that previous studies. It usually appears in the long term, with Gram-positive germs as the most frequently involved. The temporality and low recurrence rate suggest that our protocol has been effective. The high rate of reinfection orients a certain individual predisposition to suffer from CRB. Identification of potential predicting risk factors could reduce the morbimortality of these patients.

BACKGROUND AND AIMS The main vascular access for haemodialysis patients is the arteriovenous fistula (AVF). There is a high rate of early primary failure and loss of primary patency, therefore, vascular access monitoring is essential for the early diagnosis of complications and prolonging their survival. Our objective is to analyse the results of a consultation for the review and follow-up of AVFs using colour-Doppler ultrasound, performed by the nephrologist. METHOD Retrospective descriptive study of vascular ultrasounds performed from January 2019 to January 2021. Including clinical and demographic variables of the patients, as well as ultrasound parameters. Data from the Review group were compared; ultrasounds performed 3–4 weeks after performing vascular access; versus Dysfunction group; whose patients were referred from the advanced chronic kidney disease (ACKD) consultations or from the different dialysis centres upon detecting any data of suspected vascular access dysfunction. RESULTS A total of 166 vascular ultrasounds were performed: 106 (64%) in the Review group and 60 (36%) in the Dysfunction of the AVF group. A higher proportion of women was found in the Dysfunction group and upper mean age, close to the significance, P = 0.06 and P = 0.059 respectively. No significant differences were found with respect to other demographic characteristics in both groups (hypertension, diabetes, anticoagulant treatment and aetiology of kidney disease). Regarding the type of vascular access, a lower proportion of radiocephalic AVFs was observed in the Revision group (65% versus 50%) and a greater number of elbow AVFs (humero cephalic, humero basilic and humero median) in the Dysfunction group (35% versus 50%) with differences close to significance, P = 0.057. In the Review group, in 70.8% the findings were normal, in 24.5% lack of development was found, thrombosis in 9.4%, stenosis 6.6%, aneurysm 6%, oedema 17% and haematoma 6.6%. A 43% of the patients did not require to implement measures, in 42% exercise was recommended, in 6% repose of the AVF and 6 patients were requested fistulography and 3 were referred to cardiovascular surgery (CCV). In the Access Dysfunction group, the ultrasound diagnosis was normal in 28%, thrombosis was objective in 25%, stenosis 37%, aneurysm 42%, oedema 17%, haematoma 22%. 37% were referred for fistulography and 15% for revision by CCV. Regarding the ultrasound parameters, significant differences (P > 0.05) were found in terms of AVF flow, proximal and distal resistance index and vein calibre, but not in terms of vein depth and anastomosis diameter. A total of 28 fistulograms were performed, finding 86% agreement with the ultrasound findings. And in 93% the intervention was successful. Only 24% of the patients referred to the consultation required some type of intervention, and up to 65% were able to save the AVF, avoiding the realization of a new vascular access. CONCLUSION The systematic review after performing the vascular access made it possible to diagnose complications early and allow early intervention. It might be necessary to establish predictive criteria for vascular access dysfunction to individualize the follow-up for each patient, such as age, sex, or type of vascular access. Systematized vascular ultrasound by the nephrologist is very useful to preserve the functionality of the vascular access. On the other hand, the Vascular Nephrodiagnosis Consultation can avoid performing invasive and unnecessary procedures for the patient.

Presentamos dos casos de pacientes con enfermedad renal crónica G5D en programa de tratamiento renal sustitutivo (TRS) con hemodiálisis (HD) periódica e infección por SARS-CoV-2 que sufrieron trastornos del movimiento cuya aparición coincidió cronológicamente con las sesiones de hemodiálisis. El primero es una mujer de 78 años que en el día +5 de síntomas sufrió un status epiléptico mioclónico generalizado; y el segundo un varón de 46 años que en el día +10 de positividad comenzó a experimentar durante las sesiones de hemodiálisis episodios de mioclonías en miembros superiores. Las dos hipótesis con mayor fuerza para explicar la aparición de mioclonías y trastornos del sistema nerviosos central (SNC) en la enfermedad COVID-19 actualmente son el origen posthipóxico y el origen postinfeccioso inmunomediado. Es posible que la interacción entre ambos factores en pacientes con enfermedad renal, y especialmente en hemodiálisis, potencie el riesgo de sufrir estas alteraciones.