URINARY UREA NITROGEN - TOO INSENSITIVE FOR CALCULATING NITROGEN-BALANCE STUDIES IN SURGICAL CLINICAL NUTRITION
URINARY UREA NITROGEN - TOO INSENSITIVE FOR CALCULATING NITROGEN-BALANCE STUDIES IN SURGICAL CLINICAL NUTRITION
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DOI：
10.1177/0148607191015002189
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发表时间：
1991-03-01
影响因子：
3.4
通讯作者：
CERRA, FB
中科院分区：
文献类型：
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作者：
KONSTANTINIDES, FN;KONSTANTINIDES, NN;CERRA, FB
在计算氮平衡(NB)研究中的氮输出时，尿尿素氮(UUN)被用作总尿氮(TUN)的估计值。假设UUN占总氮产量的80%至90%；根据UUN估算TUN时，UUN值乘以1.25，以校正非尿素氮成分。为评价临床上测定的UUN估算尿总氮排出量的有效性，对491例普通外科/创伤患者的24小时尿标本进行了UUN：TUN配对研究，这些病人的TUN排出量为0.04~54.0g/d，并对315项NB研究进行了评估，以比较以UUN作为TUN估计值的NB值与由TUN测定值计算的NB值。两项研究中的患者被细分为四个压力类别，以TUN/天为指标：<；5g、5-10g、10-15g和>；15g。平均而言，80%到90%的Tun由UUN代表。然而，在我们的患者群体中，变异率从12%到112%不等。如果在计算Nb时使用这些UUN值作为TUN的估计值，将导致高达12g/d的偏差。在这种临床环境下，应用1.25的校正系数对非尿素氮成分进行校正是不一致的。在计算Nb时，使用实际TUN而不是估计TUN可能是比UUN更准确和合适的方法。
Urinary urea nitrogen (UUN) has been used as an estimate of total urinary nitrogen (TUN) when calculating nitrogen output for nitrogen balance (NB) studies. UUN is assumed to constitute 80 to 90% of the total nitrogen output; when estimating TUN from UUN, UUN values are multiplied by 1.25 to correct for non-urea nitrogen components. In order to evaluate the validity of estimating total urinary nitrogen output from measured UUN in a clinical setting, 491 UUN:TUN paired studies were performed on 24-hour urine collections in general surgical/trauma patients who had measured TUN outputs ranging from 0.04 to 54.0 g/d.Assessment of 315 NB studies was done to compare NB values of those calculated by using UUN as an estimate of TUN with those calculated from measured TUN. Patients in both studies were subdivided into four stress categories, using TUN/day as the index: < 5 g, 5-10 g, 10-15 g, and > 15 g.On average, 80 to 90% of TUN is represented by the UUN. However, in our patient population the variability ranged from 12 to 112%. If these UUN values are used as estimates for TUN in calculating NB, variations of up to 12 g/d would result.Application of the correction factor of 1.25 is not consistent in correcting for nonurea nitrogen components in this clinical setting. The use of actual rather than estimated TUN may be a more accurate and appropriate method than UUN when calculating NB.