不同剂量和模式连续性肾脏替代治疗对氨基酸的清除

Comparative study of amino acids clearance between various doses and modes of continuous renal replacement therapy

目的:比较不同剂量和模式连续性肾脏替代治疗(CRRT)对氨基酸的清除率。方法:4例需行CRRT治疗的急性肾损伤(AKI)患者,采用EdwardsCRRT机器进行治疗,治疗中每隔20min按如下模式进行切换:连续性血液静脉静脉透析(CVVHD)(2000ml/h和4000ml/h)、连续性静脉静脉血液滤过(CVVH)前稀释(2000ml/h和4000ml/h)、CVVH后稀释(2000ml/h和4000ml/h)。测定不同剂量及模式治疗时滤器前(置换液输入前)、滤器后、透析废液或超滤液中尿素氮(UN)、肌酐(Cr)和12种氨基酸的浓度,分别计算清除率及筛选系数(SC)。结果:天冬氨酸(Asp)和谷氨酸(Glu)的SC分别为0.5±0.04、0.48±0.07,其余10种氨基酸的SC均接近0.85。不同的剂量和模式下,UN与Cr的清除率基本相同;治疗剂量为2000ml/h时,UN和Cr在CVVHD、CVVH前稀释和CVVH后稀释模式下的清除率分别为32.7/32.68ml/min、23.95/24.69ml/min、32.62/32.22ml/min;剂量为4000ml/h时,上述三种模式的清除率分别为62.73/63.31ml/min、45.59/48.09ml/min、65.16/66.41ml/min;除了Asp和Glu,其余10种氨基酸清除率较为接近。剂量为2000ml/h时,在CVVHD、CVVH前稀释和CVVH后稀释模式下Asp和Glu的清除率分别为18.08和16.79ml/min、13.39和13.33ml/min、19.10和19.58ml/min;其余10种氨基酸的清除率分别为28.31～32.18ml/min、21.64～24.9ml/min、27.28～32.38ml/min。剂量为4000ml/h时,在上述三种模式下Asp和Glu的清除率分别为36.95和32.88ml/min、29.37和26.86ml/min、37.82和34.79ml/min;其余10种氨基酸清除率分别为59.18～64.8ml/min、46.71～50.64ml/min、58.83～65.1ml/min。结论:不同透析模式对氨基酸清除率存在一定影响,但不同治疗剂量对其影响更明显。

Objective： To evaluate the effects of different modes and doses of continuous renal replacement therapy （CRRT） on the clearance of amino acids. Methodology：Four patients requiring CRRT due to acute kidney injury were enrolled in this study. An Edward CRRT machine and AV-600 filter was used for CRRT. During each treatment session, the CRRT mode and dose was switched as following order every 20 minutes：continuous veno-venous hemodialysis （CVVHD） 2 000 ml/h ,4 000 ml/h, continuous veno-venons hemofiltration（CVVH） through pre-dilution route （pre-CVVH） 2 000 ml/ h ,4 000 ml/h, CVVH through post-dilution route （post-CVVH）2 000 ml/h,4 000 ml/h. Each time before the switching of mode or dose,the blood samples were drawn from the pre-filter site （before replacement fluid infusion in pre-CVVH mode） and post-filter site, as well as effluent samples. All specimens were measured for urea nitrogen （UN） , creatinine （Cr） , 5essential amino acids （ Valine, Methionine, Isoleucine, Leucine, Lysine） ,2 semi-essential amino acids （ Arginine, Histidine）, and 5 non-essential amino acids （ Aspartic acid, Glumatic acid, Glycine, Citrulline, Ornithine）. Sieving coefficient （SC） and clearance of all the above-mentioned solutes were calculated based on the measured data. Results：The SCs of Aspartate acid and Glumatic acid were （0. 5 ＋ 0. 04 ） and （ 0. 48 ＋ 0. 07 ）, respectively ; and the SCs of other 10 amino acids were nearly 0. 9. During various dose and mode, clearances of UN and Cr were comparable. With the dose of 2 000 mL/h, theclearances of UN/Cr under the CVVHD,Pre-CVVH, post-CVVH modes were 32. 7/32. 68 ml/min,23.95/24. 69 ml/min, 32. 62/32.22 ml/min, respectively ;while with the dose of 4 000 ml/h, the clearances of UN/Cr under the CVVHD, Pre- CVVH, post-CVVH modes were 62. 73/63.31 ml/min ,45.59/48.09 ml/min, and 65.16/66.41 ml/min, respectively. In all modes and doses, the clearance of Aspartic acid and Glumatic acid was much lower than other 10 amino acids, but without obvious differences of clearance between the 10 amino acids. With the dose of 2 000 ml/h, the clearances of Aspartate acid/ Glumatic acid under the CVVHD, Pre-CVVH, post-CVVH modes were 18. 08/16. 79 ml/min, 13.39/13.33 ml/min and 19. 1/19. 6 ml/min, respectively;while the clearance of other 10 amino acids were 28.31 -32. 18 ml/min,21.6 -24.9 mlf min and 27. 38 -32. 4 ml/min, respectively. With the dose of 4 000 ml/hr,the clearances of Aspartate aeid/Glumatic acid under the CVVHD, Pre-CVVH, post-CVVH modes were 36.95/32. 88 mL/min, 29.37/26. 86 ml/min and 37. 82/34. 79 ml/min, respectively ;while the clearance of other 10 amino acids were 59. 18 -64. 8 ml/min, 46. 71 -50. 64 ml/min and 58. 83 - 65.1 ml/min, respectively. Conehlsion：The mode of CRRT has an impact on the clearance of amino acids, but the effects of CRRT dose are more dominant.