细胞清除理论无法解释透析后小分子的反弹现象。

The cellular clearance theory does not explain the post-dialytic small molecule rebound.

作者信息

Heaf J G, Jensen S B, Jensen K, Ali S, von Jessen F

机构信息

Department of Nephrology, State University Hospital, Copenhagen, Denmark.

出版信息

Scand J Urol Nephrol. 1998 Sep;32(5):350-5. doi: 10.1080/003655998750015322.

DOI:10.1080/003655998750015322

PMID:9825399

Abstract

AIM

(a) To determine the normalized cellular clearance (Kcn) of urea, creatinine and phosphate in patients undergoing maintenance hemodialysis; (b) To identify the factors, particularly circulatory, which determine Kcn; (c) To evaluate whether intra-dialytic blood sampling can predict the size of the post-dialytic solute concentration rebound.

METHODS

Kinetic modelling of urea, creatinine and phosphate, using a two-pool variable volume computer simulation, was performed on two occasions on 34 patients undergoing maintenance dialysis. The cellular clearance was determined (a) from the size of the rebound 50 min after the end of dialysis; (b) from a mid-dialytic blood sample. Conventional two-dimensional M-mode echocardiography and Doppler peripheral blood pressure measurement were performed.

RESULTS

The model produced accurate measurements of rebound Kc for urea in 93% of measurements, creatinine in 49% and phosphate in 13%. The corresponding figures for mid-dialysis Kcn were 76%, 39% and 0%. The rebound Kcn was, for urea, 8.31 +/- 4.31 ml/kg/min, and for creatinine 4.07 +/- 2.98. The mid-dialysis Kcn was, for urea, 8.57 +/- 4.25 ml/kg/min, and for creatinine 5.06 +/- 3.36. High post-dialytic rebounds (and low Kcn values) were associated with erythropoietin use (p < 0.05) and occurrence of end-dialytic hypotension (p < 0.02). Patients treated with calcium antagonists had a significantly (p < 0.001) higher Kcn. There was no correlation between mid-dialysis and rebound Kcn. Circulatory indices had no influence on Kcn.

CONCLUSIONS

The two-pool cellular clearance model is compatible with urea kinetics, but not creatinine or phosphate. It is therefore unlikely that it is the correct model for small molecule kinetics. The post-dialytic solute rebound may be partly an iatrogenic phenomenon and can be reduced by preventing post-dialytic hypotension and by calcium antagonist treatment, both of which improve regional blood flow. The size of the rebound cannot be predicted by intra-dialytic blood sampling.

摘要

目的

(a) 测定维持性血液透析患者尿素、肌酐和磷酸盐的标准化细胞清除率（Kcn）；(b) 识别决定Kcn的因素，尤其是循环相关因素；(c) 评估透析中采血能否预测透析后溶质浓度反弹的程度。

方法

对34例维持性透析患者进行了两次尿素、肌酐和磷酸盐的动力学建模，采用双池可变体积计算机模拟。细胞清除率通过以下方式确定：(a) 根据透析结束后50分钟的反弹程度；(b) 通过透析中血样。进行了传统的二维M型超声心动图检查和多普勒外周血压测量。

结果

该模型对尿素反弹Kc的测量准确率为93%，肌酐为49%，磷酸盐为13%。透析中Kcn的相应数字分别为76%、39%和0%。尿素的反弹Kcn为8.31±4.31 ml/kg/min，肌酐为4.07±2.98。透析中尿素的Kcn为8.57±4.25 ml/kg/min，肌酐为5.06±3.36。透析后高反弹（以及低Kcn值）与使用促红细胞生成素（p<0.05）和透析结束时低血压的发生（p<0.02）相关。接受钙拮抗剂治疗的患者Kcn显著更高（p<0.001）。透析中Kcn与反弹Kcn之间无相关性。循环指标对Kcn无影响。