Choyke P L, Cady J, DePollar S L, Austin H
Department of Diagnostic Radiology, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1182, USA.
Tech Urol. 1998 Jun;4(2):65-9.
The risk of contrast-associated nephrotoxicity (CAN) is increased in the presence of preexisting renal disease. Although routine determination of serum creatinine (Cr) prior to imaging studies is the traditional method of assessing renal function, it is a costly and time-consuming practice. The purpose of this study was to investigate whether a patient survey could identify patients with a high likelihood of having normal Cr values and who, therefore, did not require serum testing. A survey was administered to 673 consecutive adult patients who were scheduled for contrast-enhanced computed tomography. Survey questions were designed to elicit a history of renal disorders as well as additional risk factors for CAN. Each patient had a Cr level determined within 48 hours prior to the injection of iodinated contrast media. Cr levels were assessed in the patients who gave negative responses to all survey questions. The degree to which positive responses to each survey question predicted elevated Cr levels was determined using the odds ratio (OR). Among the 673 respondents, 577 (85%) had normal Cr values (< or =1.3 mg/dL for women and < or =1.4 mg/dL for men). Completely negative responses to the questionnaire occurred in 191 (28%) of 673 of respondents, and 176 (92%) of these 191 had normal Cr values. A Cr cutoff value of 1.7 mg/dL is used in our department, i.e., patients with Cr values >1.7 mg/dL usually do not receive iodinated contrast media. Using this Cr cutoff value, 189 (99%) of 191 patients with negative responses had Cr values less than or equal to the cutoff value. The survey questions most strongly associated with elevated Cr values pertained to preexisting renal disease (OR 13.6), proteinuria (OR 8.7), prior kidney surgery (OR 8.1), hypertension (OR 5.4), gout (OR 4.6), and diabetes (OR 3.2). If the survey had been limited to these six questions, completely negative responses would have occurred in 450 (67%) of 673, 424 (94%) of these 450 would have normal Cr values, and 446 (99%) of 450 would have had Cr values at or below the 1.7 mg/dL cutoff for iodinated contrast. A completely negative response to a simple (six question) patient survey prior to iodinated contrast administration can identify a significant fraction of patients with normal Cr levels. Use of this survey could reduce by 67% the number of patients undergoing routine Cr determinations prior to imaging studies. This could reduce costs, decrease delays, and increase patient satisfaction associated with imaging studies.
在已有肾脏疾病的情况下，造影剂相关性肾毒性（CAN）的风险会增加。虽然在影像学检查前常规测定血清肌酐（Cr）是评估肾功能的传统方法，但这是一种成本高且耗时的做法。本研究的目的是调查患者调查问卷是否能识别出Cr值正常可能性高、因此无需进行血清检测的患者。对673例连续安排进行增强CT检查的成年患者进行了问卷调查。调查问卷的问题旨在引出肾脏疾病史以及CAN的其他风险因素。每位患者在注射碘化造影剂前48小时内测定了Cr水平。对所有调查问卷问题回答为阴性的患者评估了Cr水平。使用比值比（OR）确定每个调查问卷问题的肯定回答预测Cr水平升高的程度。在673名受访者中，577例（85%）Cr值正常（女性≤1.3mg/dL，男性≤1.4mg/dL）。673名受访者中有191例（28%）对问卷的回答完全为阴性，这191例中的176例（92%）Cr值正常。我们科室使用的Cr临界值为1.7mg/dL，即Cr值>1.7mg/dL的患者通常不接受碘化造影剂。使用这个Cr临界值，191例回答为阴性的患者中有189例（99%）的Cr值小于或等于临界值。与Cr水平升高最密切相关的调查问卷问题涉及已有肾脏疾病（OR 13.6）、蛋白尿（OR 8.7）、既往肾脏手术（OR 8.1）、高血压（OR 5.4）、痛风（OR 4.6）和糖尿病（OR 3.2）。如果调查问卷仅限于这六个问题，673例中的450例（67%）会有完全阴性的回答，这450例中的424例（94%）Cr值正常，450例中的446例（99%）的Cr值会在碘化造影剂的1.7mg/dL临界值或以下。在注射碘化造影剂前对一份简单的（六个问题的）患者调查问卷做出完全阴性的回答，可以识别出很大一部分Cr水平正常的患者。使用这份调查问卷可以将影像学检查前进行常规Cr测定的患者数量减少67%。这可以降低成本、减少延误并提高与影像学检查相关的患者满意度。
