Contributions to nephrology
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Acute kidney injury (AKI) can no longer be considered a surrogate marker for severity of illness. Recent epidemiologic data demonstrate the association of AKI and mortality. Even small decreases of kidney function are associated with increased mortality. ⋯ Infection and antimicrobial therapy can be the cause of AKI, but infection can also be a consequence of AKI. Finally, inadequate antimicrobial dosing probably plays an important role in the morbidity and mortality of AKI. These findings have led to a paradigm shift: patients die because of AKI rather than with AKI.
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Sepsis-induced acute kidney injury (AKI) is the most common form of AKI observed in critically ill patients. AKI mortality in septic critically ill patients remains high despite our increasing ability to support vital organ systems. This high mortality is partly due to our poor understanding of the pathophysiological mechanisms of sepsis-induced AKI. ⋯ Sepsis-induced renal microvascular alterations (vasoconstriction, capillary leak syndrome with tissue edema, leukocytes and platelet adhesion with endothelial dysfunction and/or microthrombosis) and/or an increase in intra-abdominal pressure could contribute to an increase in RVR. Further studies are needed to explore the time course of renal microvascular alterations during sepsis as well as the initiation and development of AKI. Doppler ultrasonography combined with the calculation of the resistive indices may indicate the extent of the vascular resistance changes and may help predict persistent AKI and determine the optimal systemic hemodynamics required for renal perfusion.
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The modern definition and classification of acute kidney injury (AKI) has now been applied to thousands of patients around the world and in different settings. Epidemiology is shedding intense light on the credibility of our fundamental notions of how AKI occurs and why. It is clear from multiple studies that sepsis is the leading etiology of AKI, although other settings associated with systemic inflammation (polytrauma, burns, pancreatitis, cardiopulmonary bypass) also represent important means of exposure. ⋯ Dissonance of mediator secretion and cell responses may lead to persistent injury and de novo chronic kidney disease. A number of soluble mediators initiate a variety of pathophysiological processes as kidney injury evolves. In this chapter, we will discuss the pathogenesis of AKI in light of new information concerning injury and repair, and focus on the controversies arising from emerging evidence.
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Comparative Study Controlled Clinical Trial
Comparison of efficacy between continuous hemodiafiltration with a PMMA high-performance membrane dialyzer and a PAN membrane hemofilter in the treatment of septic shock patients with acute renal failure.
The aim of this study was to investigate whether continuous hemodiafiltration (CHDF) with a high-performance membrane dialyzer made of polymethylmethacrylate (PMMA-CHDF) in the treatment of septic shock patients with acute renal failure (ARF) is clinically relevant. 30 patients were treated with PMMA-CHDF. 13 patients treated with CHDF used a hemofilter made of polyacrylonitrile membrane (PAN-CHDF). Systolic blood pressure significantly increased in the PMMA-CHDF group following 24 h of treatment (p < 0.01), whereas it did not improve in the PAN-CHDF group. Urine volume significantly increased in the PMMA-CHDF group following 24 h of treatment which was more than in the PAN-CHDF group (p < 0.05). 28-day survival was 83.3% in the PMMA-CHDF group and 30.8% in the PAN-CHDF group, respectively (p < 0.01). We can assume that PMMA-CHDF in the treatment of septic shock patients with ARF is clinically relevant.
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Sustained high-efficiency daily diafiltration using a mediator-adsorbing membrane (SHEDD-fA) is an effective, intensive modality for sepsis treatment. Here we describe the effectiveness of SHEDD-fA, which makes the best use of three principles: dialysis, filtration and adsorption, for mediator removal in the treatment of severe sepsis. SHEDD-fA was initiated after adequate fluid resuscitation and catecholamine support had been provided. ⋯ Because SHEDD-fA is an intensive and high-efficiency modality, removal of useful drugs or nutrients may be observed. Despite the fact that removal of useful substances cannot be ignored, we believe that an appropriate stage or timing can be identified so that we can avoid a vicious cycle and use blood purification with effective diffusion, filtration and adsorption. We demonstrate that SHEDD-fA may be an effective, intensive modality for the treatment of patients with severe sepsis and is a possible modality for cytokine modulation therapy.