發(fā)表在《胃腸病學(xué)》雜志12月刊上的研究顯示，針對肝硬化患者提出的新的急性腎損傷(AKI)共識定義比現(xiàn)行的較嚴(yán)格的定義能更準(zhǔn)確地預(yù)測該患者人群的30天死亡率和其他不良結(jié)局。

　　現(xiàn)行的舊的AKI定義要求存在肝腎綜合征且血清肌酐水平＞2.5 mg/dL。這意味著腎功能不全不那么嚴(yán)重的患者并不符合該定義且不接受治療。但最新證據(jù)表明，即使是輕度腎功能不全的預(yù)后也較差，并且單純血清肌酐并不能準(zhǔn)確反應(yīng)晚期肝硬化患者的腎功能不全。

　　因此，國際腹水協(xié)會和急性透析質(zhì)量倡議(ADQI)小組提出，肝硬化患者的AKI應(yīng)被重新定義為48 h內(nèi)血清肌酐水平增加≥0.3 mg/dl，或過去6個月內(nèi)血清肌酐水平相對穩(wěn)定基線值增加50%，不管最終血清肌酐水平如何。

　　在這項研究中，多倫多大學(xué)胃腸病科的Florence Wong醫(yī)生及其同事對新定義進(jìn)行了評估，研究對象是12個北美醫(yī)學(xué)中心2年內(nèi)收治的337例肝硬化患者，其中287例患者因細(xì)菌感染入院，50例在住院期間發(fā)生細(xì)菌感染。最常見的感染為尿路感染(27%的患者)、自發(fā)性細(xì)菌性腹膜炎(21%)、皮膚感染(14%)、肺炎(10%)和無明確感染源的自發(fā)性菌血癥(9%)。

　　這些患者中約有半數(shù)(49%)在住院期間發(fā)生至少1次AKI發(fā)作。根據(jù)新定義，發(fā)生AKI的患者的30天死亡率(34%)顯著高于不發(fā)生AKI的患者(7%)。

　　大部分發(fā)生AKI的患者均僅為1次短暫性發(fā)作，并且他們的腎功能完全恢復(fù)，但他們在后續(xù)30天內(nèi)的死亡率是無任何AKI的患者的2倍。

　　新的AKI定義的陰性預(yù)測值為93%，陽性預(yù)測值為34%。

　　該研究獲美國**衛(wèi)生院、**糖尿病、消化和腎臟疾病研究所、以及**研究資源中心支持。研究者聲明無經(jīng)濟(jì)利益沖突。

　　隨刊述評：新的腎損傷定義可預(yù)測死亡率

　　意大利米蘭大學(xué)內(nèi)科的Francesco Salerno醫(yī)生和米蘭Maggiore Policlinico醫(yī)院胃腸病科的Vincenzo La Mura醫(yī)生表示，上述研究在337例肝硬化住院患者中探討了AKI的影響。287例患者在入院時存在細(xì)菌性感染，93例在住院期間發(fā)生細(xì)菌性感染。共68例患者死于多器官衰竭，而僅7%的無AKI的患者死亡。在從AKI恢復(fù)的患者中，死亡率為15%，在未從AKI恢復(fù)的患者中，死亡率為80%。此外，76例(23%)患者發(fā)生通常與侵入性操作相關(guān)的二次感染。晚期肝病模型評分增加和二次感染是與AKI***相關(guān)的因素。因此，肝硬化合并發(fā)生AKI(即使可逆)是生存時間短的強(qiáng)烈預(yù)測因素。

　　這些結(jié)果表明，在肝硬化患者中，即使是輕微的肌酐改變(0.3 mg)也具有臨床相關(guān)性，并且AKI可能是血流動力學(xué)不穩(wěn)定的標(biāo)志且伴有多器官衰竭和死亡風(fēng)險。肝硬化患者的血流動力學(xué)改變可導(dǎo)致中樞性血容量減少。我們除了應(yīng)保護(hù)患者免于發(fā)生感染和AKI之外，還應(yīng)更加留意那些可增加血清肌酐水平的臨床操作。這兩名醫(yī)生聲明無相關(guān)經(jīng)濟(jì)利益沖突。

　　原文：By: MARY ANN MOON, Internal Medicine News Digital Network

　　The newly proposed consensus definition of acute kidney injury in patients with cirrhosis accurately predicts 30-day mortality and other adverse outcomes in this patient population much better than the current, more rigid definition would, according to a report in the December issue of Gastroenterology (doi:10.1053/j.gastro.2013.08.051).

　　In what they described as the largest prospective study of this topic to date, researchers found that the recently proposed, broader redefinition of acute kidney injury (AKI) correctly identified which patients were likely to die, develop severe complications such as organ failure, or require longer hospitalization, even when the AKI was transient and resolved completely after treatment.

　　More than half of the patients in this study who had episodes of AKI according to the new definition did not meet the criteria of the old definition. So using the new definition will help identify these high-risk patients at an earlier stage of renal dysfunction, "well before the stringent diagnostic criteria of [the old definition] are reached," when they will have a better treatment response, said Dr. Florence Wong of the division of gastroenterology, University of Toronto, and her associates.

　　The old definition of AKI required the presence of hepatorenal syndrome, with a serum creatinine level of greater than 2.5 mg/dL. This meant that patients with less severe renal dysfunction didn’t qualify and weren’t treated. But emerging evidence indicates that even mild degrees of renal dysfunction signal a poor prognosis, and that serum creatinine alone doesn’t accurately reflect renal dysfunction in advanced cirrhosis.

　　So the International Ascites Club and the Acute Dialysis Quality Initiative (ADQI) group proposed that acute kidney injury in cirrhosis should be redefined as an increase in serum creatinine level of 0.3 mg/dL or greater within 48 hours, or a 50% increase in serum creatinine level from a stable baseline reading within the previous 6 months, regardless of final serum creatinine level.

　　Dr. Wong and her colleagues assessed the new definition in a cohort of 337 cirrhotic patients treated during a 2-year period at 12 North American medical centers who were admitted with a bacterial infection (287 subjects) or who developed a bacterial infection during hospitalization (50 subjects). The most common infections were urinary tract infection (27% of patients), spontaneous bacterial peritonitis (21%), skin infection (14%), pneumonia (10%), and spontaneous bacteremia with no clear source of infection (9%).

　　Approximately half of these patients (49%) developed at least one episode of AKI during hospitalization. The 30-day mortality was significantly higher for those who developed AKI according to the new definition (34% mortality) than in those who did not (7% mortality), the investigators said.

　　Most patients who developed AKI had only a transient case, and their renal function completely recovered. Yet their subsequent mortality within 30 days was twice as high as that for patients who didn’t have any AKI.

　　The negative predictive value of the new definition of AKI was 93%, and the positive predictive value was 34%.

　　This study was supported in part by the National Institutes of Health, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Center for Research Resources. No financial conflicts of interest were reported.

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　　New definition of kidney injury predicts mortality

　　Renal dysfunction in patients with cirrhosis is often associated with sepsis. This combination involves a very high probability of death. Recently, the concept of acute kidney injury has been proposed to be extended also to renal failure occurring in patients with cirrhosis. AKI should overcome limitations associated with a fixed creatinine threshold, ensure rapid identification of renal dysfunction, and allow timely treatment in patients with hepatorenal syndrome. However, AKI should also overcome the skepticism of those who wish not to abandon previous definitions.

　　The recent paper of Dr. Wong and her colleagues explored the impact of AKI in 337 hospitalized patients with cirrhosis. Two-hundred eighty-seven patients had bacterial infection at admission, and 93 developed it during hospitalization. Overall, 68 patients died from multiorgan failure, whereas only 7% of patients without AKI died. Mortality ranged from 15% in patients who recovered from AKI to 80% in those who did not. Moreover, 76 patients (23%) developed a second infection, often associated with invasive procedures! An elevated Model for End-Stage Liver Disease score and a second infection were factors independently associated with AKI. Accordingly, the development of AKI in cirrhosis, even if reversible, was shown to be a strong predictor of short survival.

　　These findings show that, in cirrhosis, even small creatinine changes (0.3 mg) are clinically relevant, and that AKI is probably a hallmark of hemodynamic instability with a risk of multiorgan failure and death. The altered hemodynamics in patients with cirrhosis cause central hypovolemia. Aiming at protecting our patients from infection and AKI, we should also pay more attention to clinical procedures that raise serum creatinine level.

　　Dr. Francesco Salerno is in the department of internal medicine, at the Policlinico IRCCS San Donato, University of Milan (Italy); Dr. Vincenzo La Mura is with the Fondazione IRCCS Ca'Granda, in the department of gastroenterologia-1 of the Hospital Maggiore Policlinico, Milan. They reported no relevant financial conflicts.