| Abstract |
Yuk-Lun Cheng, Koon-Shing Choi, Chee-Unn Yung, Kim-Ming Wong, Ka-Foon Chau, Chun-Sang Li, Kwong-Yuen Tsang, Chi-Kwan Wong, Yee-Tuen Tsui, Alex W.Y. Yu
Background: Despite the fact that
thrice-weekly hemodialysis is regarded as the standard for maintenance dialysis,
prescription of twice-weekly hemodialysis with a longer treatment time is common
in Hong Kong to allow more renal failure patients to receive treatment. In an
attempt to assess whether clinical and biochemical parameters differ between
hemodialysis with different interdialytic intervals, we investigated the urea
kinetics and blood biochemistry parameters in patients undergoing two dialysis
sessions per week.
Methods: Data were collected for 16 anuric stable maintenance dialysis patients
for two dialyses in the same week.
Results: Compared with hemodialysis after a short interdialytic interval (HDSII),
hemodialysis after a long inter-dialytic interval (HDLII) led to significantly
greater interdialytic weight gain. Predialysis plasma potassium, urea and creatinine
concentrations were significantly higher for HDLII. On the other hand, there
were no significant differences in predialysis plasma sodium, chloride, total
carbon dioxide, albumin, calcium and phosphorus concentrations and anion gap
between HDSII and HDLII. Both immediate postdialysis and 30-minute postdialysis
plasma urea concentrations were significantly higher for HDLII. Urea removal,
creatinine removal, modified urea reduction ratio (mURR), single-pool Kt/V (spKt/V)
and equilibrated Kt/V (eKt/V) were significantly greater for HDLII. Moreover,
there was a good linear relationship between mURR for HDSII and HDLII. Similar
findings were noted for both spKt/V and eKt/V. However, there were no differences
between the two dialyses in urea reduction ratio, normalized protein equivalent
of total nitrogen appearance and postdialysis urea rebound.
Conclusion: Our findings suggest that there are differences in some dialysis
indices and blood biochemistry parameters between HDSII and HDLII. Standardization
of dialysis sessions (HDSII or HDLII) for blood sampling schedules is needed
to permit meaningful comparison of dialysis indices and biochemistry parameters
within and between dialysis patients.
Key words: urea kinetics, biochemistry parameters, hemodialysis schedule, twice-weekly hemodialysis
背景: 長期血液透析的頻率一般建議為一週 3 次，然而為了讓更多的腎衰竭患者接受治療，在香港有不少病人正接受一週
2 次時間較長的透析。本研究對一週 2 次的透析接受者作出研究，調查了透析間隔（interdialytic
interval） 的長短對尿素動力學及血液生化指標的影響。 方法: 研究數據來自 16
位正在接受一週 2 次長期血液透析的無尿症患者。
結果: 相比於透析間隔較短的病人（HDSII），間隔較長者（HDLII）的體重出現明顯增加﹔HDLII
之透析前血漿鉀、尿素、及肌酸酐濃度亦較高。兩組之間在其他指標上則相同，包括透析前血漿鈉、氯、總二氧化碳、白蛋白、鈣、磷、及陰離子間隙。在透析剛完成及 30
分鐘後，HDLII 的血漿尿素濃度顯著高於 HDSII；尿素清除量、肌酸酐清除量、修正後之尿素下降比率（mURR）、單一體積（single-pool）之
Kt/V（spKt/V）、及平衡後（equilibrated）之
Kt/V（eKt/V）
亦以 HDLII 較高。HDSII
與 HDLII 組中在 mURR
上呈現良好的線性關係；同樣的情形亦可見於 spKt/V
及 eKt/V。然而，兩組之間在尿素下降比率、總氮出現量之正常化蛋白質當量（nPNA）（normalized
protein equivalent of total nitrogen appearance）、及透析後之尿素反彈上相似。