Sorkness R
JPEN J Parenter Enteral Nutr. 1984 May-Jun;8(3):300-1. doi: 10.1177/0148607184008003300.
Urine urea nitrogen excreted in 24 hr is used to estimate nitrogen balance in patients. Normal diurnal variation of urea excretion may be less pronounced in patients alimented continuously, and a urine collection of shorter duration may be representative of the 24-hr excretion. Five stabilized trauma center patients on continuous enteral or parenteral alimentation were studied with six consecutive 4-hr urine collections analyzed for urine urea nitrogen content. Excretion rates for various lengths of urine collection were compared with the 24-hr excretion rate. Urine collections spanning 4 or 8 hr frequently exceeded an error of 10% in predicting 24-hr urea nitrogen excretion, while collections of 12 hr or more had small errors. A comparison of three consecutive 8-hr collections was suggestive of diurnal variation existing under these conditions.
24小时尿尿素氮排泄量用于评估患者的氮平衡。持续接受营养支持的患者，尿素排泄的正常昼夜变化可能不那么明显，较短时间的尿液收集可能代表24小时排泄量。对5名在稳定创伤中心接受持续肠内或肠外营养支持的患者进行了研究，连续收集6次4小时尿液，分析尿尿素氮含量。将不同时长尿液收集的排泄率与24小时排泄率进行比较。4小时或8小时的尿液收集在预测24小时尿素氮排泄量时，误差常常超过10%，而12小时或更长时间的收集误差较小。连续三次8小时收集结果的比较表明在这些情况下存在昼夜变化。
