Beta-lactams have recently emerged as extensively utilized antimicrobial agents, and their judicious administration significantly influences the outcome of critically ill patients. In critical illness, the pharmacokinetics of beta-lactams deviate markedly from those observed in healthy individuals, exhibiting considerable temporal variability and interindividual differences related to disease status. In clinical practice, beta-lactam dosage adjustments are commonly implemented based on the renal replacement therapy (RRT) setting. However, significant variability is known to exist in blood concentrations, primarily due to underlying pharmacokinetic changes. Despite attempts to estimate approximate clearance from the RRT setting, detecting patients who deviates optimal drug concentration remains challenging due to this variability. Conversely, beta-lactams demonstrate a favorable safety profile; however, dose reductions are recommended when trough concentrations surpass 6 to 10 times the Minimum Inhibitory Concentration (MIC) considering their potential toxicity. This recommendation holds particular significance in the early stages of severe diseases, where pharmacokinetics are unpredictable and patient outcomes are substantially influenced. Consequently, this emphasizes the desirability of dosing strategies aimed at ensuring sufficient blood levels.

Heart and kidney failure frequently coexist in clinical practice because they share common elements in their pathophysiology. Kidney failure that complicates heart failure includes not only renal ischemia but also renal congestion. Decongestion becomes an effective treatment not only for heart failure but also for renal failure in cases of heart failure complicated by renal congestion. Decongestion methods include diuretic administration and extracorporeal ultrafiltration (ECUM). ECUM becomes essential if renal function deteriorates and adequate diuresis cannot be achieved with diuretics alone despite the requirement for rapid intravascular congestion improvement. Some reports indicate that ECUM is superior to diuretics in terms of decongestion capability and safety. However, studies indicated that safety and renal outcomes worsen with increased decongestion volume and duration. Treatment is required while considering renal ischemia. Considering renal ischemia is crucial when selecting diuretics. Central venous pressure is an effective indicator for assessing the presence of renal congestion, and we hope to discover simpler methods as alternatives.

In recent years, research on acute kidney injury (AKI) and kidney replacement therapy (KRT) has advanced significantly. This article examines the recommendations for the timing of KRT initiation in the Japanese Clinical Practice Guidelines for Management of Sepsis and Septic Shock (J-SSCG) 2020．Notably, the guidelines include a recommendation for KRT initiation timing, which is divided into two based on severity. The first part does not provide specific recommendations regarding AKI Stage 2, whereas the second part advises against early KRT initiation in AKI Stage 3．The reason for this disparity is that the referenced randomized controlled trials had different patient backgrounds and study designs. The J-SSCG guidelines are revised every four years, and future iterations are expected to include further advancements in AKI management.

In continuous kidney replacement therapy (CKRT), the venous chamber (VC) is a site where blood coagulation is common, and one of the factors is blood retention. In this study, we investigated the effect of a vertical inflow VC on blood retention, focusing on three retention factors: blood flow rate (QB), supplemental fluid flow rate (QS), and liquid layer separation. VC was used JCH-55X2-CHDF-2 (JMS). The evaluation items were classified as QB (80, 150 mL/min), QS (0, 0.3, 0.6 L/hr), and the presence of liquid layer separation. These were examined in a total of 12 ways. The QB had a strong stirring effect in the middle and bottom of the VC, and high QB reduced retention more than low QB; the use of QS reduced retention in the top of the VC through dilution and the effect of a drop impact on the VC liquid surface. Liquid layer separation reduced the drop impact on the VC liquid surface, but positively affected the turning force of blood flow. The combination of high QB, use of QS, and liquid layer separation reduces retention throughout the vertical inflow VC.

[Introduction] The flow in a venous air trap chamber of the CKRT circuit was visualized using computational fluid dynamics simulation to investigate the effects of different chamber designs. [Methods] A 33% glycerin solution (working fluid) was poured into a 15 mL venous air trap chamber at a flow rate of 150 mL/min, and this was visualized by the simulation method. The effects of the inflow method of fluid flow into the venous air trap chamber, and the presence of a filter were evaluated. The results of each simulation case calculation are illustrated with streamlines and the velocity contour of the flow field. [Results] In the horizontal inflow method, the working fluid flowed down to the outlet with a swirling motion, regardless of the presence or absence of a filter, and the flow rectification effect of the filter was confirmed at the bottom of the venous air trap chamber. [Conclusion] Computational fluid dynamics simulation revealed that a flow without stagnation was achieved throughout the venous air trap chamber throughout which the horizontal inflow method and filter facilitated fluid flow without stagnation.

In hemodialysis units, incidents associated with conventional blood purification therapies have been comprehensively documented through nationwide surveys, which have informed the creation of corresponding safety manuals. However, there is a dearth of detailed reports on incidents involving acute blood purification therapies for critically ill patients, highlighting a significant gap in safety measures. At our institution, we have undertaken a thorough analysis of incidents related to acute blood purification and implemented safety protocols based on these insights. Consequently, despite concerns regarding an uptick in incidents due to evolving work environments, the incidence of level ≥3a incidents associated with acute blood purification has declined over the past 5 years. This underscores the efficacy of strategies such as task standardization, process visualization, simplification, and interdisciplinary collaboration in mitigating incidents in acute blood purification therapy.

Thrombus formation has been reported to occur relatively early after the insertion of non-cuffed hemodialysis catheters（NCCs）. Complications arising from thrombus formation include the risk of catheter dysfunction, such as inadequate de-bleeding, pulmonary thromboembolism, severe catheter-related bloodstream infection, and vascular stenosis or occlusion. This study focused on patients who underwent ultrasonography at the time of NCC removal among those who underwent blood purification using NCCs at our center. NCCs were inserted into the right internal jugular vein in 14 patients and into the left internal jugular vein in five patients. The median（IQR）duration of NCC placement was 7（6-11）days. A high frequency of thrombus formation was observed in 17 of 19 patients（89.5％）. NCCs are often utilized in emergencies when blood purification is required. However, it should be noted that a high percentage of thrombi forms in the insertion vessel during blood purification.

In acute blood purification therapy, it is crucial to use a hemofilter that shows low blood cell adhesion in order to prevent hemofilter clotting, which can have a significant impact on patients, staff, and medical resources. The aim of the present study was to investigate the basic performance of two hemofilters made of different materials using an in vitro experimental model. We utilized fresh porcine blood obtained from a single animal for the experiments, and compared the blood cell adhesion characteristics between Hemofeel^Ⓡ SNV（SNV）and UT Filter^Ⓡ（UT）using in vitro experimental model. The filtrate was returned to the circulating blood. The experiment was conducted for 24 hours with a blood flow rate of 100 mL/min and filtrate flow rate of 10 mL/min. The heparin addition rate was adjusted to maintain an activated clotting time of 200-300 s during the experiment. The results revealed that UT showed a higher change of the transmembrane pressure（TMP）during the 24-hour hemofiltration and a greater amount of red blood cells and total blood cells in residual blood clotting adhering to the membrane, as compared to SNV. Thus, SNV showed a lower TMP and lower blood cell adhesion than UT.

A 79-year-old woman presenting gastrointestinal symptoms, which began one week prior, was admitted to the hospital. Initially, antineutrophil cytoplasmic antibody (ANCA) -associated vasculitis triggered by a severe acute respiratory syndrome coronavirus 2 infection was suspected. Upon admission, she experienced severe acute renal failure, followed by the development of acute respiratory distress syndrome, necessitating artificial respirator management and treatment involving cytokine adsorbing hemofilter continuous hemodiafiltration (CAH-CHDF) intermittently using PMMA membrane and direct hemoperfusion with polymyxin B immobilized fiber (PMX-DHP) to adsorb cytokines for circulatory and respiratory failure, leading to improvement. On day 5 of hospitalization, a positive ANCA result prompted the initiation of half-pulse steroid therapy. On day 9, an HCU staff member tested positive for coronavirus disease 2019 (COVID-19), and upon retesting, the patient’s PCR test was also positive. As our hospital policy does not permit the treatment of patients with COVID-19 requiring intubation management, she was transferred to a university hospital in an intubated state. Despite being intubated-extubated three times, she returned to our hospital’s nursing care ward 4 months later in a wheelchair, having undergone tracheostomy and maintenance hemodialysis.

Background: Tumor lysis syndrome（TLS）is a life-threatening disorder characterized by multiple organ failure resulting from the rapid collapse of malignant tumors. Here, we present a pediatric case of T-cell acute lymphocytic leukemia（T-ALL）accompanied by hyperkalemia induced by TLS, requiring emergency hemodialysis. Case: A 15-year-old boy, weighing 52.9 kg was diagnosed with T-ALL and was identified as a high-risk for TLS. Following the initiation of prednisolone（15 mg/m²）, his serum potassium and creatinine levels increased to 7.3 mmol/L and 1.77 mg/dL, respectively. An electrocardiogram revealed T wave elevation, prompting the administration of emergency hemodialysis（HD）to address the hyperkalemia and acute renal failure due to TLS. We prescribed a blood flow rate of 160 mL/min and a dialysate flow rate of 500 mL/min, using heparin as an anticoagulant. After 4 hours, potassium and creatinine levels improved to 4.4 mmol/L and 0.81 mg/dL, respectively and the patient is currently undergoing maintenance therapy for T-ALL. Conclusion: The modality of renal replacement therapy（RRT）is necessary to consider for each case and to perform RRT promptly when necessary.

Thrombotic thrombocytopenic purpura（TTP）is a well-known condition associated with hemolytic anemia. We report a case of paroxysmal nocturnal hemoglobinuria（PNH）that was initially suspected to be TTP based on the detection of fragmented red blood cells. A woman in her 60s presented to our hospital with fatigue. Laboratory findings indicated hemolytic anemia with 1.2％ fragmented red blood cells, elevated lactate dehydrogenase（LDH）and decreased haptoglobin levels, renal dysfunction, thrombocytopenia, and positive COVID-19 results. The clinical presentation suggested thrombotic microangiopathy, which led to a high index of clinical suspicion of TTP with COVID-19．LDH levels reduced following therapeutic plasma exchange; however, the platelet count only marginally improved. Analysis of red blood cell surface markers CD55 and CD59 revealed deficiencies, confirming the diagnosis of PNH. Although PNH typically does not alter red blood cell morphology, red blood cell fragmentation may occasionally occur, warranting an accurate differential diagnosis.

Septic acute kidney injury plays a significant role in reducing mortality rates among septic patients requiring ICU admission. Essentially, implementing renoprotective measures in patients with sepsis holds promise for enhancing their general status. Our department’s treatment strategy is characterized by combinations of physiological and pharmacological approaches to preserving renal function. We examine the physiological evidence supporting this strategy, which includes the selection of antimicrobial agents and infusion management, and the utilization of circulatory agonists, diuretics, and blood purification. The core of this strategy is the maintenance of urinary flow and regulation of mediators as needed. Maintaining urinary flow for renal protection is crucial due to the potential tubular obstruction resulting from the filtration of cytokines and other substances from the bloodstream into raw urine, resulting in tubular epithelial damage and a subsequent decline in glomerular filtration rate（GFR）. To maintain urinary flow, our institution strives to maintain urinary flow as much as possible, rather than solely depending on fluid removal through blood purification for water balance. Blood purification is administered with a keen focus on controlling blood and urine mediators, with treatment conditions tailored to the patient’s specific disease status.

Blood volume monitoring system（BV monitoring system）is considered as one of the most important monitoring items during dialysis for safe treatment in the chronic phase. Although TR-2020 was initially equipped with the BV monitoring system in the acute setting, there are not many reports available regarding its accuracy. Therefore, we investigated the accuracy of the TR-2020 BV monitoring system in measuring ⊿BV（⊿BV_TR）in vitro. In this study, a bovine blood circulation model was established, and blood was circulated from the model to the TR-2020. During clinical simulation of transfusion and draining, ⊿BV_TR and ⊿BV（⊿BV_control）were measured under continuous fluid replacement, draining, and replacement/draining conditions and compared. According to Bland-Altman analysis, fixed errors in the negative direction was observed during fluid replacement, and during draining, replacement/draining, absolute error of ⊿BV_control and ⊿BV_TR showed an increasing tendency during fluid replacement. In addition, since LOA（limits of agreement）were within the range of error for the BV monitoring system during dialysis in the chronic phase, use as a monitoring system for CRRT（continuous renal replacement therapy）is also considered possible.