Adult Critical Care Unit, The Royal London Hospital, Bart's and the London NHS Trust, London, UK.
Curr Opin Crit Care. 2012 Dec;18(6):585-92. doi: 10.1097/MCC.0b013e328358d480.
Global renal blood flow is considered pivotal to renal function. Decreased global renal blood flow (decreased perfusion) is further considered the major mechanism of reduced glomerular filtration rate responsible for the development of acute kidney injury (AKI) in critically ill patients. Additionally, urinary biochemical tests are widely taught to allow the differential diagnosis of prerenal (functional) AKI and intrinsic [structural AKI (so-called acute tubular necrosis)]. In this review we will examine recent evidence regarding these two key clinical paradigms.
Recent animal experiments and clinical studies in humans using cine-phase contrast magnetic resonance technology are not consistent with the decreased perfusion paradigm. They suggest instead that changes in the intra-renal circulation including modification in efferent arteriolar function and intra-renal shunting are much more likely to be responsible for AKI, especially in sepsis. Similarly, recent human studies indicate the urinary biochemistry has limited diagnostic or prognostic ability and is dissociated form biomarker and microscopic evidence of tubular injury.
Intra-renal microcirculatory changes are likely more important than changes in global blood flow in the development of AKI. Urinary biochemistry is not a clinically useful diagnostic or prognostic tool in critically ill patients at risk of or with AKI.
全球肾血流量被认为对肾功能至关重要。全球肾血流量减少（灌注减少）被进一步认为是导致危重病患者急性肾损伤（AKI）肾小球滤过率降低的主要机制。此外，广泛教授尿生化检查以允许对肾前性（功能性）AKI 和内在[结构性 AKI（所谓的急性肾小管坏死）]进行鉴别诊断。在这篇综述中，我们将检查这两个关键临床范例的最新证据。
最近使用电影相位对比磁共振技术的动物实验和人体临床研究与灌注减少的范例不一致。相反，它们表明，包括传出小动脉功能改变和肾内分流在内的肾内循环变化更可能导致 AKI，尤其是在脓毒症中。同样，最近的人体研究表明，尿生化检查在诊断或预后方面的能力有限，并且与肾小管损伤的生物标志物和显微镜证据分离。
在 AKI 的发展中，肾内微循环变化可能比整体血流变化更为重要。尿生化检查在有发生 AKI 风险或患有 AKI 的危重病患者中不是一种临床有用的诊断或预后工具。
