Development of a new miniaturized system for ultrafiltration.

Acute decompensated heart failure and fluid overload are the most common causes of hospitalization in heart failure patients, and often, they contribute to disease progression. Initial treatment encompasses intravenous diuretics although there might be a percentual of patients refractory to this pharmacological approach. New technologies have been developed to perform extracorporeal ultrafiltration in fluid overloaded patients. Current equipment allows to perform ultrafiltration in most hospital and acute care settings. Extracorporeal ultrafiltration is then prescribed and conducted by specialized teams, and fluid removal is planned to restore a status of hydration close to normal. Recent clinical trials and European and North American practice guidelines suggest that ultrafiltration is indicated for patients with refractory congestion not responding to medical therapy. Close interaction between nephrologists and cardiologists may be the key to a collaborative therapeutic effort in heart failure patients. Further studies are today suggesting that wearable technologies might become available soon to treat patients in ambulatory and de-hospitalized settings. These new technologies may help to cope with the increasing demand for the care of chronic heart failure patients. Herein, we provide a state-of-the-art review on extracorporeal ultrafiltration and describe the steps in the development of a new miniaturized system for ultrafiltration, called AD1 (Artificial Diuresis).

Sodium-glucose cotransporter 2 inhibition in primary and secondary glomerulonephritis.

BACKGROUND: The role of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in the management glomerular/systemic autoimmune diseases with proteinuria in real-world clinical settings is unclear. METHODS: This is a retrospective, observational, international cohort study. Adult patients with biopsy-proven glomerular diseases were included. The main outcome was the percentage reduction in 24-h proteinuria from SGLT2i initiation to 3, 6, 9 and 12 months. Secondary outcomes included percentage change in estimated glomerular filtration rate (eGFR), proteinuria reduction by type of disease and reduction of proteinuria ≥30% from SGLT2i initiation. RESULTS: Four-hundred and ninety-three patients with a median age of 55 years and background therapy with renin-angiotensin system blockers were included. Proteinuria from baseline changed by -35%, -41%, -45% and -48% at 3, 6, 9 and 12 months after SGLT2i initiation, while eGFR changed by -6%, -3%, -8% and -10.5% at 3, 6, 9 and 12 months, respectively. Results were similar irrespective of the underlying disease. A correlation was found between body mass index (BMI) and percentage proteinuria reduction at last follow-up. By mixed-effects logistic regression model, serum albumin at SGLT2i initiation emerged as a predictor of ≥30% proteinuria reduction (odds ratio for albumin <3.5 g/dL, 0.53; 95% CI 0.30-0.91; P = .02). A slower eGFR decline was observed in patients achieving a ≥30% proteinuria reduction: -3.7 versus -5.3 mL/min/1.73 m2/year (P = .001). The overall tolerance to SGLT2i was good. CONCLUSIONS: The use of SGLT2i was associated with a significant reduction of proteinuria. This percentage change is greater in patients with higher BMI. Higher serum albumin at SGLT2i onset is associated with higher probability of achieving a ≥30% proteinuria reduction.

Sorbent functionalization with vancomycin enhances bacteria killing in extracorporeal hemoadsorption.

BACKGROUND: The level of bacteremia in patients with sepsis and septic shock is a predictor of complications and mortality, regardless of the type of bacteria. Devices for bacteria, endotoxin and cytokines removal by adsorption have been recently developed. Thus, extracorporeal blood purification therapies have been proposed as adjunctive therapy in sepsis in combination with drugs. Some potentially useful drugs, however, are precluded due to their organ or metabolic toxicity. The present study represents a preliminary report on the in vitro effect of a sorbent device (minimodule with HA380 beads, Jafron medical, Zhuhai, China) in which the particles have been functionalized with vancomycin on the surface. The impact of the surface-modified beads on circulating bacteria (Staphylococcus aureus) has been tested in a simulated in vitro circulation. METHODS: In vitro experiments were carried out with 800 mL of blood enriched with S. aureus species. Blood was circulated in the vancomycin-functionalized and non-functionalized mini-module cartridges in hemoadsorption setup (300 mL each) and the bactericidal effect was assessed. Also, 200 mL of blood was used as a control. RESULTS: A significant increase in the time to positivity of blood cultures was observed after 60 min and also after 120 min of therapy with the mini-module functionalized with vancomycin as opposed to the non-functionalized cartridge. CONCLUSIONS: These results suggest a possible way of treating sepsis by using drug- or antibiotic-functionalized cartridges without worrying about pharmacological toxicity. The prolongation of the time to bacterial culture positivity to S. aureus after a passage through a column packed with beads functionalized with vancomycin represents a proof of concept.

ULTRAFILTRATION TOLERANCE, A PHENOTYPE THAT WE NEED TO RECOGNIZE.

BACKGROUND: The evaluation and management of fluid balance are key challenges in critical care patients who require renal replacement therapies because cumulative fluid balance is an independent factor that increases morbidity and mortality in different clinical scenarios. SUMMARY: One of the strategies when fluid overload is refractory to diuretics, is extracorporeal fluid removal (i.e., net ultrafiltration [UFNET] during kidney replacement therapy). However, problems with UFNET without individualized assessment are cardiovascular events and intradialytic hypotension, events that contribute to decreasing organ perfusion and sympathetic stress. Therefore, we must consider and try to predict the best timing for the start of ultrafiltration and find the point where the patient is most tolerant to ultrafiltration, making a simile to the concept of fluid tolerance. KEY MESSAGES: UFNET is a continuous and dynamic process, going through moments of tolerance and intolerance to ultrafiltration; as nephrologists, we must take the necessary measures to move through this period.

Effect of Mechanical Vibration on Kinetics of Solute Adsorption.

INTRODUCTION: Hemadsorption with new sorbent cartridges is an emerging extracorporeal blood purification technique. Flow distribution inside the sorbent is one of the main issues concerning the device's performance and optimal sorbent utilization. In this experiment, we aimed to investigate the efficacy of vibration during adsorption by measuring the removal of vancomycin. METHODS: In this experimental study, 1,000 mL of saline with 10 g of vancomycin was circulated in a closed circuit (set flow of 250 mL/min) simulating a hemadsorption blood run using HA380 minimodule cartridge containing 75 g of wet resin. This vibration model was implemented with a damping head device installed in front of the adsorption cartridge during the experiment. The kinetics of the vancomycin were assessed by removal ratio over 120 min. RESULTS: We found no difference between the two models. Adsorption with and without vibration did not differ significantly for partial reduction ratios, overall amount of adsorbed molecule, or adsorption kinetics. CONCLUSION: The current design and structure of the minimodule cartridge demonstrated no difference in small-middle solute removal. Further improvement with the addition of mechanical vibration to the device was not observed.

Peritoneal dialysis and acute kidney injury in acute brain injury patients.

Acute kidney injury (AKI) is a heterogeneous syndrome with multiple etiologies. It occurs frequently in the neurocritical intensive care unit and is associated with greater morbidity and mortality. In this scenario, AKI alters the kidney-brain axis, exposing patients who receive habitual dialytic management to greater injury. Various therapies have been designed to mitigate this risk. Priority has been placed by KDIGO guidelines on the use of continuous over intermittent acute kidney replacement therapies (AKRT). On this background, continuous therapies have a pathophysiological rationale in patients with acute brain injury. A low-efficiency therapy such as PD and CRRT could achieve optimal clearance control and potentially reduce the risk of secondary brain injury. Therefore, this work will review the evidence on peritoneal dialysis as a continuous AKRT in neurocritical patients, describing its benefits and risks so it may be considered as an option when deciding among available therapeutic options.

Acute kidney injury in neurocritical care.

Approximately 20% of patients with acute brain injury (ABI) also experience acute kidney injury (AKI), which worsens their outcomes. The metabolic and inflammatory changes associated with AKI likely contribute to prolonged brain injury and edema. As a result, recognizing its presence is important for effectively managing ABI and its sequelae. This review discusses the occurrence and effects of AKI in critically ill adults with neurological conditions, outlines potential mechanisms connecting AKI and ABI progression, and highlights AKI management principles. Tailored approaches include optimizing blood pressure, managing intracranial pressure, adjusting medication dosages, and assessing the type of administered fluids. Preventive measures include avoiding nephrotoxic drugs, improving hemodynamic and fluid balance, and addressing coexisting AKI syndromes. ABI patients undergoing renal replacement therapy (RRT) are more susceptible to neurological complications. RRT can negatively impact cerebral blood flow, intracranial pressure, and brain tissue oxygenation, with effects tied to specific RRT methods. Continuous RRT is favored for better hemodynamic stability and lower risk of dialysis disequilibrium syndrome. Potential RRT modifications for ABI patients include adjusted dialysate and blood flow rates, osmotherapy, and alternate anticoagulation methods. Future research should explore whether these strategies enhance outcomes and if using novel AKI biomarkers can mitigate AKI-related complications in ABI patients.

Subarachnoid Hemorrhage and Extracorporeal Blood Purification with HA-380 and High-Volume Hemofiltration: A New Therapeutic Challenge at the Neurocritical Care Unit? A Case Report.

We present the case of a patient with subarachnoid hemorrhage (SAH) secondary to a ruptured cerebral aneurysm and a refractory shock with high doses of vasopressors without a proven source of infection. This patient received therapy with high-volume hemofiltration plus adsorption, resolving the hemodynamic deterioration and with good neurological evolution. Our clinical case proposes that extracorporeal therapies may have a feasibility role in the management of complications of SAH.

Acute Kidney Injury at the Neurocritical Care Unit.

Neurocritical care has advanced substantially in recent decades, allowing doctors to treat patients with more complicated conditions who require a multidisciplinary approach to achieve better clinical outcomes. In neurocritical patients, nonneurological complications such as acute kidney injury (AKI) are independent predictors of worse clinical outcomes. Different research groups have reported an AKI incidence of 11.6% and an incidence of stage 3 AKI, according to the Kidney Disease: Improving Global Outcomes, that requires dialysis of 3% to 12% in neurocritical patients. These patients tend to be younger, have less comorbidity, and have a different risk profile, given the diagnostic and therapeutic procedures they undergo. Trauma-induced AKI, sepsis, sympathetic overstimulation, tubular epitheliopathy, hyperchloremia, use of nephrotoxic drugs, and renal hypoperfusion are some of the causes of AKI in neurocritical patients. AKI is the result of a sum of events, although the mechanisms underlying many of them remain uncertain; however, two important causes that merit mention are direct alteration of the physiological brain-kidney connection and exposure to injury as a result of the specific medical management and well-established therapies that neurocritical patients are subjected to. This review will focus on AKI in neurocritical care patients. Specifically, it will discuss its epidemiology, causes, associated mechanisms, and relationship to the brain-kidney axis. Additionally, the use and risks of extracorporeal therapies in this group of patients will be reviewed.

[Single-pass albumin dialysis as treatment of acute on chronic liver failure during COVID-19 pneumonia. report of one case]. / Diálisis de albúmina de paso único (SPAD) como soporte hepático extracorpóreo en paciente COVID-19 crítico. Caso clínico.

Liver transplantation is the only effective therapy to reduce the high mortality associated with acute liver failure and acute on chronic liver failure (ACLF). Single-pass albumin dialysis (SPAD) is an extracorporeal supportive therapy used as a bridge to liver transplantation or regeneration. We report a 44-year-old man with alcoholic cirrhosis admitted for critical COVID-19 pneumonia that evolves with ACLF. SPAD technique was performed completing six sessions, with a reduction of bilirubin and ammonia levels. He evolved with severe respiratory failure and refractory septic shock, dying. SPAD is a safe and efficient technique aimed to eliminate liver toxins, preventing multiorgan damage interrupting the process known as the "autointoxication hypothesis". It is easy to implement in any critical patient unit and has lower costs than other extracorporeal liver support therapies.

[Management of refractory septic shock with blood purification therapy using a special filter. Report of one case]. / COVID-19, shock séptico refractario y terapia extracorpórea de purificación sanguínea con OXIRIS®.

Sepsis is one of the leading causes of death in critically ill patients with COVID-19 and blood purification therapies have a role to immunomodulate the excessive inflammatory response and improve clinical results. One of the devices designed for these therapies is the oXiris® filter, allowing to perform renal replacement therapy combined with selective adsorption of endotoxins and cytokines. We report a 55-year-old male with COVID who developed a septic shock secondary to a sepsis caused by Pseudomona aeruginosa, refractory to the usual management. A veno-venous continuous hemofiltration was started using the oXiris® filter for 48 hours. Subsequently, there was an improvement in clinical perfusion parameters and a reduction in inflammatory markers. The patient was discharged from the intensive care one month later.

[Therapeutic plasma exchange. Experience in 102 patients]. / Intercambio plasmático terapéutico por plasmafiltración: experiencia de 11 años de un centro.

BACKGROUND: Therapeutic Plasma Exchange (TPE) is a procedure in which plasma and harmful macromolecules are separated from the rest of the blood components by centrifugation or filtration through membranes and are replaced with solutions with albumin and/or plasma. AIM: To communicate our experience using TPE by filtration. MATERIAL AND METHODS: Review of records of 655 TPE sessions performed in 102 patients aged 50 ± 18 years (64% women). The requirement of renal replacement therapy (RRT) and seven days and one year mortality were recorded. RESULTS: Forty five percent of patients had hypertension or diabetes. The main indications for TPE were pulmonary-renal syndrome (PRS) (62%) and antibody mediated graft rejection (29%), followed by neurological diseases (36%). Fifteen percent of patients required RRT for one year. Mortality at seven days and one year was 20 and 30%, respectively. Out of the total of deaths associated with kidney diseases, 88% corresponded to PRS and ANCA vasculitis. The main complications were thrombocytopenia in 41%, hypocalcemia in 18%, and hypotension in 16%. CONCLUSIONS: In our experience, TPE by filtration is a safe technique, with mild and preventable complications. Despite this, the reported mortality is high, which reflects the severity of the diseases that motivated the indication for TPE.

Long-term plasmapheresis therapy in the management of focal segmental glomerulosclerosis recurrence after kidney transplantation.

The recurrence of primary focal segmental glomerulosclerosis (FSGS) after kidney transplantation (KT) appears in 30 % of the recipients. Sometimes it can cause the loss of the allograft. Although many treatments for this condition have been reported, 20 %-40 % of the affected patients are refractory or presents frequents relapses. In this paper we describe the evolution of three recipients treated with long-term plasmapheresis therapy after a recurrence of FSGS with a bad or incomplete response to other treatments. Although our findings require confirmation, long-term plasmapheresis could be a therapeutic option for this condition.

Early Cytokine Removal in Critical COVID-19 Patients with Extracorporeal Therapies (HA-380 plus High Volume Hemofiltration) May Prevent Progression of Acute Respiratory Distress Syndrome: Case Report.

We present the case of a patient who suffered from acute respiratory distress syndrome caused by pneumonia associated with COVID-19 and cytokine release syndrome. This patient received a high-volume hemofiltration plus adsorption, solving the hemodynamic deterioration, pulmonary infiltrates, and gas exchange. Our clinical case proposes that the extracorporeal therapies can have a role in the management of severe COVID-19.

[Bilateral renal papillary necrosis of spontaneous resolution as a cause of microscopic hematuria. Report of one case]. / Necrosis papilar renal bilateral de resolución espontánea como causa de hematuria microscópica. Caso clínico.

Renal papillary necrosis is an infrequent cause of hematuria characterized by ischemic necrosis of the renal medulla, especially the papilla. Its most common cause is analgesic abuse. Despite being oligo-symptomatic, in many cases its presence is associated with serious functional sequelae. Imaging, especially computed tomography, is essential to make the diagnosis. We report a 63-year-old female studied for an asymptomatic microscopic hematuria whose tomographic study showed a bilateral renal papillary necrosis. No etiology was found, and she evolved with a spontaneous complete remission.

The role of peritoneal dialysis in the treatment of acute kidney injury in neurocritical patients: a retrospective Brazilian study.

BACKGROUND: Acute kidney injury (AKI) occurs frequently in the neurocritical intensive care unit and is associated with greater morbidity and mortality. AKI and its treatment, including acute kidney replacement therapy, can expose patients to a secondary greater brain injury. This study aimed to explore the role of peritoneal dialysis (PD) in neurocritical AKI patients in relation to metabolic and fluid control, complications related to PD and outcome. METHODS: Neurocritical AKI patients were treated by PD (prescribed Kt/V = 0.40/session) using a flexible catheter and a cycler and lactate as a buffer. RESULTS: A total of 58 patients were included. The mean age was 61.8 ± 13.2 years, 65.5% were in the intensive care unit, 68.5% needed intravenous inotropic agents, 72.4% were on mechanical ventilation, APACHE II was 16 ± 6.67 and the main neurological diagnoses were stroke (25.9%) and intracerebral haemorrhage (31%). Ischaemic acute tubular necrosis (iATN) was the most common cause of AKI (51.7%), followed by nephrotoxic ATN AKI (25.8%). The main dialysis indications were uraemia and hypervolemia. Blood urea and creatinine levels stabilised after four sessions at around 48 ± 11 mg/dL and 2.9 ± 0.4 mg/dL, respectively. Negative fluid balance and ultrafiltration increased progressively and stabilised around 2.1 ± 0.4 L /day. Weekly delivered Kt/V was 2.6 ± 0.31. The median number of high-volume PD sessions was 6 (4-10). Peritonitis and mechanical complications were not frequent (8.6% and 10.3%, respectively). Mortality rate was 58.6%. Logistic regression identified as factors associated with death in neurocritical AKI patients: age (odds ratio (OR) = 1.14, 95% confidence interval (CI) = 1.09-2.16, p = 0.001), nephrotoxic AKI (OR = 0.78, 95% CI = 0.69- 0.95, p = 0.03), mechanical ventilation (OR = 1.54, 95% CI = 1.17-2.46, p = 0.01), intracerebral haemorrhage as main neurological diagnoses (OR = 1.15, 95% CI = 1.09-2.11, p = 0.03) and negative fluid balance after two PD sessions (OR = 0.94, 95% CI = 0.74-0.97, p = 0.009). CONCLUSION: Our study suggests that careful prescription may contribute to providing adequate treatment for most neurocritical AKI patients without contraindications for PD use, allowing adequate metabolic and fluid control, with no increase in the number of infectious, mechanical and metabolic complications. Mechanical ventilation, positive fluid balance and intracerebral haemorrhage were factors associated with mortality, while patients with nephrotoxic AKI had lower odds of mortality compared to those with septic and ischaemic AKI. Further studies are needed to investigate better the role of PD in neurocritical patients with AKI.

Adsorption Mass Transfer Zone of Vancomycin in Cartridges With Styrene-Divinylbenzene Sorbent.

Cartridges for hemoadsorption containing styrene-divinylbenzene sorbent are used for multiple conditions, such as intoxication. The mass transfer zone comprises the extension along the longitudinal span of the cartridge where adsorption occurs. The aim of this experiment is to evaluate the mass transfer zone for vancomycin in the HA380 cartridge. The experiment was carried out twice. A saline solution with vancomycin passed through a HA380-modified cartridge at 100 ml/min in a single-pass fashion. The cartridge had four openings along its longitudinal dimension, at 3, 6, 9, and 12 cm. In both experiments, the collection of aliquots occurred at minute 4, in the four openings and pre- and post-cartridge, and an additional sample from the effluent bag at the end of each experiment. In the second experiment, an additional sampling of the same six sites occurred at minute 14. The sigmoidal shape of the curve for the mass transfer zone of vancomycin was similar to the theoretical one. In experiment one, at minute 4, vancomycin clearance was 98.75 ml/min. In experiment two, vancomycin clearance at minutes 4 and 14 was 93.76 and 93.20 ml/min, respectively. This implies an adequate and optimal design of the HA380 cartridge.

Acute kidney injury in neurocritical patients: a retrospective cohort study.

BACKGROUND /OBJECTIVE: Acute kidney injury (AKI) is a significant complication in critical care units (CCU). Non-neurological complications such as AKI are an independent predictor of poor clinical outcomes, with an increase in morbidity and mortality, financial costs, and worse functional recovery. This work aims to estimate the incidence of AKI and evaluate the risk factors and complications of AKI in neurocritical patients hospitalized in the CCU. METHODS: A retrospective cohort study was conducted. Patients admitted to the neurocritical care unit between 2016 and 2018 with a stay longer than 48 h were retrospectively analyzed in regard to the incidence, risk factors, and outcomes of AKI. RESULTS: The study population comprised 213 neurocritical patients. The incidence of AKI was 23.5%, with 58% KDIGO 1 and 2% requiring renal replacement therapy. AKI was an independent predictor of prolonged use of mechanical ventilation, cerebral edema, and mortality. Cerebral edema [OR 4.40 (95% CI 1.98-9.75) p < 0.001] and a change in chloride levels greater than 4 mmol/L at 48 h (OR 2.44 (95% CI 1.10-5.37) p = 0.027) were risk factors for developing AKI in the first 14 days of hospitalization. CONCLUSION: There is a high incidence of AKI in neurocritical patients; it is associated with worse clinical outcomes regardless of the CCU admission etiology or AKI severity.