Rachoin Jean-Sebastien, Daher Ralph, Moussallem Charles, Milcarek Barry, Hunter Krystal, Schorr Christa, Abboud Mariam, Henry Patricia, Weisberg Lawrence S
Division of Critical Care Medicine, Department of Medicine, Cooper University Hospital, Camden, NJ, USA.
Nephrol Dial Transplant. 2012 Jun;27(6):2248-54. doi: 10.1093/ndt/gfr705. Epub 2011 Dec 29.
Acute kidney injury (AKI) is common in critically ill patients and is associated with a high mortality rate. Pre-renal azotemia, suggested by a high blood urea nitrogen to serum creatinine (BUN:Cr) ratio (BCR), has traditionally been associated with a better prognosis than other forms of AKI. Whether this pertains to critically ill patients is unknown.
We conducted a retrospective observational study of two cohorts of critically ill patients admitted to a single center: a derivation cohort, in which AKI was diagnosed, and a larger validation cohort. We analyzed associations between BCR and clinical outcomes: mortality and renal replacement therapy (RRT).
Patients in the derivation cohort (N = 1010) with BCR >20 were older, predominantly female and white, and more severely ill. A BCR >20 was significantly associated with increased mortality and a lower likelihood of RRT in all patients, patients with AKI and patients at risk for AKI. Patients in the validation cohort (N = 10 228) with a BCR >20 were older, predominantly female and white, and more severely ill. A BCR >20 was associated with increased mortality and a lower likelihood of RRT in all patients and in those at risk for AKI, BUN correlated with age and severity of illness.
A BCR >20 is associated with increased mortality in critically ill patients. It is also associated with a lower likelihood of RRT, perhaps because of misinterpretation of the BCR. Clinicians should not use a BCR >20 to classify AKI in critically ill patients.
急性肾损伤（AKI）在危重症患者中很常见，且与高死亡率相关。传统上，血尿素氮与血清肌酐（BUN:Cr）比值（BCR）升高提示的肾前性氮质血症，其预后较其他形式的AKI更好。这是否适用于危重症患者尚不清楚。
我们对入住单一中心的两组危重症患者进行了一项回顾性观察研究：一个推导队列，其中诊断出AKI；以及一个更大的验证队列。我们分析了BCR与临床结局（死亡率和肾脏替代治疗（RRT））之间的关联。
推导队列（N = 1010）中BCR>20的患者年龄更大，主要为女性和白人，病情更严重。BCR>20与所有患者、AKI患者和有AKI风险的患者死亡率增加及RRT可能性降低显著相关。验证队列（N = 10228）中BCR>20的患者年龄更大，主要为女性和白人，病情更严重。BCR>20与所有患者及有AKI风险的患者死亡率增加及RRT可能性降低相关，BUN与年龄和疾病严重程度相关。
BCR>20与危重症患者死亡率增加相关。它还与RRT可能性降低相关，可能是由于对BCR的误解。临床医生不应使用BCR>20对危重症患者的AKI进行分类。
