Gubensek Jakob, Orsag Alesa, Ponikvar Rafael, Buturovic-Ponikvar Jadranka
Department of Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
PLoS One. 2016 Dec 28;11(12):e0168593. doi: 10.1371/journal.pone.0168593. eCollection 2016.
Regional citrate anticoagulation (RCA) during hemodialysis interferes with calcium homeostasis. Optimal ionized calcium (iCa) target range during RCA and consequent calcium balance are unknown.
In a randomized controlled trial (ACTRN12613001029785) 30 chronic hemodialysis patients were assigned to normal (1.1-1.2 mmol/) or low (0.95-1.05 mmol/l) iCa target range during a single hemodialysis with RCA. The primary outcome was calcium mass balance during the procedure, using a partial spent dialysate collection method; magnesium mass balance was also measured. Intact parathormone (iPTH), total calcium (tCa) and magnesium were measured before and after procedures.
Mean iCa during procedures was significantly different in the two groups (1.12±0.06 in normal and 1.06±0.07 mmol/l in low iCa group, p <0.001), resulting in different tCa (2.18±0.22 vs. 1.95±0.17, p = 0.003) after the procedure. Mean delivered calcium during the procedure was 58.3±4.8 mmol in the normal and 51.5±8.2 mmol in the low iCa group (p = 0.010), which resulted in a significantly higher mean positive calcium mass balance of 14.6±8.3 mmol (584±333 mg) per procedure in normal as compared to 7.2±8.5 mmol (290±341 mg) in low iCa group (p = 0.024). Linear mixed effects model showed a significant interaction effect of time and iCa target range group on iPTH, i.e. a significant increase in iPTH in the low as compared to normal iCa target group (p = 0.008). Magnesium mass balance was mildly negative and comparable in both groups.
Low iCa target range resulted in a significantly less positive calcium mass balance, but in a significant increase in iPTH. To achieve a more neutral calcium balance, we recommend allowing a mild hypocalcemia during hemodialysis with RCA, especially when it is used for prolonged periods.
血液透析期间的局部枸橼酸盐抗凝（RCA）会干扰钙稳态。RCA期间的最佳游离钙（iCa）目标范围以及随之而来的钙平衡尚不清楚。
在一项随机对照试验（ACTRN12613001029785）中，30例慢性血液透析患者在单次RCA血液透析期间被分配至正常（1.1 - 1.2 mmol/L）或低（0.95 - 1.05 mmol/L）iCa目标范围组。主要结局是使用部分用过的透析液收集方法测量的该过程中的钙质量平衡；同时也测量了镁质量平衡。在操作前后测量了完整甲状旁腺激素（iPTH）、总钙（tCa）和镁。
两组在操作期间的平均iCa有显著差异（正常组为1.12±0.06，低iCa组为1.06±0.07 mmol/L，p<0.001），导致操作后tCa不同（2.18±0.22对1.95±0.17，p = 0.003）。操作期间正常组平均输送钙量为58.3±4.8 mmol，低iCa组为51.5±8.2 mmol（p = 0.010），这使得正常组每次操作的平均正钙质量平衡显著高于低iCa组，分别为14.6±8.3 mmol（584±333 mg）和7.2±8.5 mmol（290±341 mg）（p = 0.024）。线性混合效应模型显示时间和iCa目标范围组对iPTH有显著交互作用，即与正常iCa目标组相比，低iCa目标组的iPTH显著增加（p = 0.008）。两组镁质量平衡均为轻度负值且相当。
低iCa目标范围导致正钙质量平衡显著减少，但iPTH显著增加。为实现更中性的钙平衡，我们建议在使用RCA进行血液透析期间允许轻度低钙血症，尤其是在长期使用时。
