Large molecular weight substances such as cytokines are related to the pathogenesis of sepsis. Therefore, continuous hemofiltration (CHF) is appropriate for treatment of septic AKI because CHF is superior to other modalities of continuous blood purification for clearance of large molecular weight substances. Modalities of CHF include pre-dilution and post-dilution methods. Pre-dilution CHF has the demerit of a decrease in the clearance of small or middle molecular weight substances, and post-dilution CHF has the demerit of shortening of the filter life-time and inappropriate biocompatibility. Data obtained from a clinical setting and an in vivo experiment using test solutions showed that pre-dilution CHF had a stronger inhibitory effect on excess activation of leukocytes and platelets than did post-dilution CHF. On the other hand, post-dilution CHF was superior for clearance of small or middle molecular weight substances, but pre-dilution CHF and post-dilution CHF showed no difference in clearance of large molecular weight substances, which are related to sepsis. Pre-dilution CHF is recommended for patients with septic AKI because of its superiority of biocompatibility and equality of clearance of large molecular weight substances. Fortunately, a new machine that can perform pre-dilution CHF has been developed and has recently become available in Japan, we should establish implementation of CHF depending on clinical features.

Acute kidney injury (AKI) is one of the most serious conditions among hospitalized patients, particularly for critically ill patients in the intensive care unit. Despite significant advances in dialysis technology, the mortality in patients with AKI severe enough to require renal replacement therapy (RRT) remains unacceptably high. Several single center studies have revealed that high intensity CRRT is associated with improved mortality. Since then, it has been thought that intensive CRRT should be desirable for patients with AKI. However, two large multicenter randomized controlled trials have shown that higher doses of continuous RRT (CRRT) for AKI do not lead to improved survival. On the other hand, in Japan, patients with AKI usually receive lower doses of CRRT. To date, studies have not verified whether significant differences in survival result from the CRRT dose used in Japan versus the international standard dose. We discuss the optimal intensity of CRRT in critically ill patients with AKI.

We developed a flow visualization system based on laser Doppler velocimetry, and succeeded in visualizing swirling flow in the chamber as a flow velocity distribution. In this study, 45 wt% glycerin aqueous solution was used to simulate the viscosity of blood with a hematocrit of 35％. The average flow velocity and shear rate in the whole area tended to increase with increasing flow rate of the blood pump. A comparison of the flow velocity distributions and blood coagulation tests confirmed that coagulation occurred significantly for slow flow velocity below 100 mL/min. This method enables investigation of the quantitative relationship between the flow velocity and coagulation.

【Background】Maintaining hemodynamic stability is vital for safe hemodialysis (HD) therapy. At present, circulatory dynamics are measured as appropriate. In this study, pulse and blood pressure are tracked via an automatic monitoring system to secure safer HD treatment and to enable remote monitoring and control via the detection and issuance of alerts. This study also aims to assist the development of instruments for remote monitoring and control. 【Method】We developed a wristwatch-like device that measures blood pressure and pulse and conducted a validation study on its effectiveness. We also constructed an IoT-type setup in which the measurement results are automatically sent to and stored on a server. 【Results】Each measurement item in our device provided the same level of detection accuracy as existing medical devices. Measurement results were managed on a server using an IoT system, and alerts were successfully triggered. 【Conclusion】There is potential for our system to be adopted in clinical practice to enable less stressful or demanding monitoring of patients and to ensure that the necessary alerts are issued by managing data using servers. We anticipate that more comprehensive safety management can be achieved by enhancing and improving the treatment environment for dialysis patients in this way.

We investigated the predictive factors of circuit coagulation during continuous renal replacement therapy (CRRT) using recombinant human soluble thrombomodulin (rTM). 43 patients who underwent CRRT with rTM (rTM-CRRT) at our hospital between May 2015 and May 2019 were divided into two groups. The coagulation group (n=10) included patients who required circuit replacement owing to early coagulation and non-coagulation group (n=33) included patients who underwent periodic circuit replacement. The examination items were APACHEⅡ score, SOFA score before CRRT was started, DIC score, blood test (blood cell count, serum chemistry, and coagulation system), and activated clotting time(ACT) on the blood effusion side at the start of CRRT. As a result of multivariant analysis, a significant difference was observed in soluble fibrin(SF) of the coagulation system only. Therefore, SF value before the initiation of CRRT may be possibly predict the occurrence of circuit coagulation during rTM-CRRT.

Among patients with critical conditions requiring intensive care, those at a high risk of hemorrhagic complications are being treated with anticoagulant-free dialysis at our facility since January 2014. Furthermore, the devices such as dialysis catheters and air-trap chambers used at our facility have been changed to newer variants since October 2018. This retrospective study aimed to identify the factors affecting the completion rate of anticoagulant-free dialysis and to determine the impact of the device changes on the completion rate. In total, 70 anticoagulant-free dialysis sessions were performed in 27 patients. Poor blood removal was significantly more common in patients with premature termination of dialysis (P=0.002). Moreover, the completion rate increased from 86.5% before the device changes to 100％ after the device changes. Innovative use of devices to prevent clotting in the blood purification circuit was suggested to contribute to the successful completion of anticoagulant-free dialysis. Anticoagulant-free dialysis performed with innovative devices appears to be an important and safe therapeutic option for patients at a high risk of hemorrhagic complications.

Daptomycin (DAP) is an antibiotic used to treat methicillin-resistant Staphylococcus aureus. The recommended dosage for patients undergoing continuous renal replacement therapy (CRRT) is 6-8mg/kg every 24-48h in Europe and the US. However, it is assumed that the pharmacokinetics in the Japanese CRRT setting is different, and thus, we examined the pharmacokinetics of DAP in four patients. The DAP dosage was 7.1 (IQR: 5.8-8.1) mg/kg every 48h. The modality for CRRT was continuous hemodiafiltration in two patients and continuous hemodialysis in two patients. The elimination half-life（t_1/2）, area under the drug concentration-time curve (AUC), and minimum concentration (C_min) were 20.7（19.5-20.6）h, 904 (525-1,281) mg・h/L, and 10.2 (8.2-10.5) mg/L, respectively. The t_1/2 values were longer in this study than that reported in previous studies. With presumed minimum inhibitory concentration (MIC), AUC/MIC values achieved the efficacy target and C_min values were low within the safety target. The dosage of DAP in patients undergoing CRRT is recommended as ＞6mg/kg every 48h, although clinical validation for the dosage is required.

【Purpose】To investigate nursing care provided by ICU nurses at our hospital for the patients undergoing blood purification therapy, and to identify practical issues in this nursing. 【Subjects and Methods】A questionnaire survey was conducted on “physical care,” “mental care,” and “social care” for 40 ICU nurses at our hospital. 【Results】“Physical care” reduced physical burdens such as equipment management, reduction of physical risk factors associated with rest, and pain control. “Mental care” alleviated pain and discomfort, responded quickly to alarms, and incorporated change-of-distance therapy tailored to the preference of each patient.“Social care” provided information to other wards and helped to understand the support system of family members, but has yet to lead to activities directly related to life after hospital discharge. Establishment of an approach leading to discharge support is an issue for future consideration. 【Conclusion】In nursing care for patients undergoing blood purification therapy in an ICU, it is important to fully understand the patient’s social background, lifestyle, and family support. There is a need for early intervention that takes into account the life support system for the patient after leaving the ICU, and not only that at ICU entry.

During blood purification under extracorporeal circulation, the temperature of the returning blood decreases naturally because of contacting the external temperature. Blood purification systems can be used with various methodologies to prevent natural decreases in temperature. However, the temperature change in the returning blood may vary depending on the heating techniques and purification conditions of different systems. In this study, we used the influent fluid heating ACH-Σ (Σ) and blood circuit heating prismaflex (PF) to examine the effects of different heating techniques and purification conditions on the returning blood temperature. These experiments were carried out at room temperature (25℃) with 37℃ warmer water circulated in both systems. The returning blood temperature was recorded by varying the blood, substitution fluid, and dialysate flow rates. When the substitution fluid and dialysate flow rates increased at room temperature, the returning blood temperature drastically decreased in the PF because of the direct flows of the substitution fluid and dialysate into the blood. Meanwhile, the blood flow rate change proportionally affected the blood return temperature irrespective of the system. We thought that this was due to the reduced contact time at room temperature with the blood circuit. In the case of the PF, the temperature decrease was minimal at low blood flow rates due to direct heating of the returning blood circuit. We conclude that the risk of hypothermia might be resolved by understanding the heating methodologies of different blood purification systems.

【Background】Prismaflex^®, which was launched in 2018, this feature is expected to reduce coagulation within the circuit. 【Method】We divided TR-55X^® （Toray Medical） and Prismaflex^® (Baxter) used in our hospital, in order to retrospectively compare the effects on coagulation within the circuit. 【Results】Frequency of unexpected circuit exchange was significantly higher in the P group (p=0.003). The returning blood pressure was significantly higher in the TR group (p=0.003). There were four “other causes” other than increased return blood pressure and increased inlet pressure only in the P group. 【Conclusion】There were many unexpected circuit changes with P group, due to blood coagulation in the hemofilter or deviations in the operating procedure; consequently, going forward, it was considered that the results could be improved by improving the hemofilter and mastering the operation.