Zia Ziabari Seyyed Mahdi, Rimaz Siamak, Shafaghi Afshin, Shakiba Maryam, Pourkazemi Zahra, Karimzadeh Elnaz, Amoukhteh Melika
Department of Emergency Medicine, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Anesthesiology Department, Anesthesiology Research Center, Alzahra Hospital, Guilan University of Medical Sciences, Rasht, Iran.
Arch Acad Emerg Med. 2019 Jun 2;7(1):e30. eCollection 2019.
Finding easily accessible and non-invasive methods for differentiating various sources of gastrointestinal (GI) bleeding before performing endoscopy and colonoscopy is of great interest. The present study was designed with the aim of evaluating the screening performance characteristics of blood urea nitrogen (BUN) to Creatinine (Cr) ratio in this regard.
The present diagnostic accuracy study was performed on patients with acute GI bleeding presenting to emergency department from 2011 to 2016, in a retrospective manner. BUN/Cr ratio was calculated for all patients and its accuracy in differentiation of upper and lower GI bleedings, confirmed via endoscopy or colonoscopy, was evaluated.
A total of 621 patients with the mean age of 59.49±17.94 (5 - 93) years were studied (60.5% male). Area under the receiver operating characteristic (ROC) curve of BUN/Cr ratio for predicting the source of GI bleeding was 0.63 (95% CI: 0.57 - 0.68). Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of BUN/Cr ratio at 35 cut-off point were 19.63% (95%CI: 16.69 - 23.45), 90.16% (95%CI: 83.11 - 94.88), 89.09 (95%CI: 81.35 - 93.98), 21.53 (95%CI: 18.09 - 25.39), 8.16 (95%CI:4.76 - 13.98), and 3.65 (95%CI: 3.44 - 3.87), respectively.
Considering the relatively proper specificity and positive predictive value of BUN/Cr ratio, in cases that bleeding source cannot be determined using other non-invasive methods, values higher than 35 can predict upper GI bleeding with high probability. However, due to the low sensitivity, values less than 35 are not diagnostic.
在进行内镜检查和结肠镜检查之前，寻找易于获取且非侵入性的方法来区分胃肠道（GI）出血的各种来源具有重要意义。本研究旨在评估血尿素氮（BUN）与肌酐（Cr）比值在这方面的筛查性能特征。
本诊断准确性研究以回顾性方式对2011年至2016年到急诊科就诊的急性GI出血患者进行。计算所有患者的BUN/Cr比值，并评估其在内镜检查或结肠镜检查确诊的上、下消化道出血鉴别中的准确性。
共研究了621例患者，平均年龄为59.49±17.94（5 - 93）岁（男性占60.5%）。BUN/Cr比值预测GI出血来源的受试者操作特征（ROC）曲线下面积为0.63（95%CI：0.57 - 0.68）。在截断点为35时，BUN/Cr比值的敏感性、特异性、阳性和阴性预测值以及阳性和阴性似然比分别为19.63%（95%CI：16.69 - 23.45）、90.16%（95%CI：83.11 - 94.88）、89.09（95%CI：81.35 - 93.98）、21.53（95%CI：18.09 - 25.39）、8.16（95%CI：4.76 - 13.98）和3.65（95%CI：3.44 - 3.87）。
考虑到BUN/Cr比值相对合适的特异性和阳性预测值，在无法使用其他非侵入性方法确定出血来源的情况下，高于35的值可高度预测上消化道出血。然而，由于敏感性较低，低于35的值无诊断意义。
