Contributions to nephrology
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Continuous hemoperfusion therapies are now widely used in critical care, and could prove to be life-saving for patients unable to receive regular hemoperfusion treatments. Unfortunately, due to the inherent difficulties in assessing the effects of treatment upon critically ill patients, the efficacy of this modality has yet to be proven. Instead of focusing exclusively on a particular form of continuous hemoperfusion or a direct comparison between the different types available, this report provides a general overview of the studies reporting on its efficacy across a wide range of conditions. The authors conclude that continuous hemoperfusion could be beneficial in some cases, but this is highly dependent upon the particular modality used.
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The correct selection of anticoagulation in acute blood purification is crucial for avoiding exacerbation of bleeding in critical care patients with acute renal failure, as these patients frequently exhibit hemorrhagic complications. The mode of acute blood purification is determined mainly by the patient's hemodynamic stability, and continuous renal replacement therapies (CRRTs) have been extensively performed for patients with hemodynamic instability. Unfractionated heparin, low molecular weight heparin and nafamostat mesilate (nafamostat) are available in acute blood purification for the patients. ⋯ This is especially the case with patients of small stature, which is the case for many Japanese people. Nafamostat can be used safely in CRRT for critical care patients with acute renal failure and bleeding risks, because it acts as a regional anticoagulant due to its pharmacological characteristics. Nafamostat has been widely used in acute blood purification at critical care units in Japan.
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Polymyxin B fiber column is a medical device designed to reduce blood endotoxin levels in sepsis. Gram-negative-induced abdominal sepsis is likely to be associated with high circulating endotoxin. In June 2009, the EUPHAS study (Early Use of Polymyxin B Hemoperfusion in Abdominal Sepsis) was published in JAMA. ⋯ The PaO(2)/FiO(2) ratio increased slightly (235 to 264; p = 0.049) in the polymyxin B group, but not in the conventional therapy group (217 to 228; p = 0.79). SOFA scores improved in the polymyxin B group, but not in the conventional therapy group (change in SOFA: -3.4 vs. -0.1; p = 0.001), and 28-day mortality was 32% (11/34 patients) in the polymyxin B group and 53% (16/30 patients) in the conventional therapy group (unadjusted HR: 0.43, 95% CI: 0.20-0.94; adjusted HR: 0.36, 95% CI:0.16-0.80). The study demonstrated how polymyxin B hemoperfusion added to conventional therapy significantly improved hemodynamics and organ dysfunction and reduced 28-day mortality in a targeted population with severe sepsis and/or septic shock from intra-abdominal Gram-negative infections.
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Continuous renal replacement therapy (CRRT) has been extensively used in Japan as renal support for critically ill patients managed in the ICU. In Japan, active research has also been conducted on non-renal indications for CRRT, i.e. the use of CRRT for purposes other than renal support. Various methods of blood purification have been attempted to remove inflammatory mediators, such as cytokines, in patients with severe sepsis or septic shock. ⋯ In evaluating the efficacy of CRRT for non-renal indications, it is essential to focus on patients subjected to be studied, such as severe sepsis or septic shock, and to evaluate its indication, commencement, termination of therapy and also its therapeutic effects based on analysis of blood levels of the target substances to be removed (e.g. cytokines). IL-6 blood level appears to be useful as a variable for this evaluation. It is expected that evidence endorsing the validity of these methods now being attempted in Japan will be reported near future.
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Acute kidney injury (AKI) is a common complication of critical illness. While the etiology of AKI in critically ill patients is likely often multifactorial, sepsis has consistently been found an important contributing factor and has been associated with high attributable morbidity and mortality. Accordingly, the timely identification of septic AKI in critically ill patients is clearly a clinical priority. ⋯ In addition, several urinary biochemical tests, derived indices and microscopy have also been widely cited as valuable in the diagnosis and classification of AKI. However, the value of these urinary tests in the diagnosis, classification, prognosis and clinical management in septic AKI remains unclear, due in part to a lack of kidney morphologic changes and histopathology in human studies of septic AKI. This review will summarize the urinary biochemistry and microscopy in septic AKI.