Division of Nephrology, Department of Clinical Sciences, Lund University, Lund, Sweden.
Diaverum Spain, Madrid, Spain.
J Ren Nutr. 2023 Mar;33(2):326-331. doi: 10.1053/j.jrn.2022.06.006. Epub 2022 Jul 2.
Substantial levels of residual renal clearance and urine output may occur in patients treated with hemodialysis or hemodiafiltration. However, the relationships among residual renal urea, creatinine, and phosphate clearances, respectively, and between clearances and urine volume have not been well described.
We performed a prospective, cross-sectional study which enrolled hemodialysis and hemodiafiltration patients with a urine volume of >100 mL/day, in whom at least 2 residual renal clearances were obtained over a 6-month observation period. Urine was collected for 24 hours prior to the midweek treatment session and concentrations of urea, creatinine, and phosphate were measured.
Thirty-eight patients (24 men, 14 women) with a mean age of 70.4 ± 12.4 (SD) years were included in this analysis. All patients were dialyzed 3 times per week with mean treatment duration of 243 ± 7.89 minutes. Twenty patients were undergoing hemodiafiltration and 18 patients high-flux hemodialysis. In total, 102 dialysis sessions, of which 52 were hemodiafiltration, and urine collections were analyzed. Mean urine volume was 457 ± 254 mL per 24 hours. Residual renal clearance rates of urea (Kr Urea), creatinine (Kr Cr), and phosphate (Kr Phos) were 1.60 ± 0.979, 4.69 ± 3.79, and 1.98 ± 1.36 mL/minute, respectively. Mean ratios of Kr Cr/Kr Urea, Kr Phos/Kr Urea, and Kr Phos/Kr Cr were 2.83 ± 1.21, 1.23 ± 0.387, and 0.477 ± 0.185, respectively. There was a modest correlation between Kr Phos and daily urine volume (r = 0.605, P = .001).
In maintenance hemodialysis and hemodiafiltration patients, residual renal phosphate clearance is approximately 23% higher than residual renal urea clearance. Urine volume is a modestly accurate surrogate for estimating residual renal phosphate clearance, but only when urine volume is <300 mL/day.
接受血液透析或血液透析滤过治疗的患者可能会出现大量残余肾清除率和尿量。然而，残余肾尿素、肌酐和磷酸盐清除率之间的关系，以及清除率与尿量之间的关系尚未得到很好的描述。
我们进行了一项前瞻性、横断面研究，纳入了尿量>100 mL/天的血液透析和血液透析滤过患者，这些患者在 6 个月的观察期内至少获得了 2 次残余肾清除率。在每周中间治疗前 24 小时收集尿液，并测量尿素、肌酐和磷酸盐的浓度。
本分析共纳入 38 例患者（24 例男性，14 例女性），平均年龄 70.4±12.4（SD）岁。所有患者每周透析 3 次，每次治疗持续时间平均为 243±7.89 分钟。20 例患者行血液透析滤过，18 例患者行高通量血液透析。共分析了 102 次透析和 52 次血液透析滤过以及尿液采集。平均尿量为 457±254 mL/24 小时。尿素（Kr Urea）、肌酐（Kr Cr）和磷酸盐（Kr Phos）的残余肾清除率分别为 1.60±0.979、4.69±3.79 和 1.98±1.36 mL/分钟。Cr Cr/Kr Urea、Kr Phos/Kr Urea 和 Kr Phos/Kr Cr 的平均比值分别为 2.83±1.21、1.23±0.387 和 0.477±0.185。Kr Phos 与每日尿量之间存在适度相关性（r=0.605，P=0.001）。
在维持性血液透析和血液透析滤过患者中，残余肾磷酸盐清除率比残余肾尿素清除率高约 23%。尿量是一种较为准确的估计残余肾磷酸盐清除率的替代指标，但仅在尿量<300 mL/天时适用。
