Kozik-Jaromin Justyna, Nier Volker, Heemann Uwe, Kreymann Bernhard, Böhler Joachim
Fresenius Medical Care, Bad Homburg, Germany.
Nephrol Dial Transplant. 2009 Jul;24(7):2244-51. doi: 10.1093/ndt/gfp017. Epub 2009 Feb 5.
Regional citrate anticoagulation is a very effective anticoagulation method for haemodialysis. However, it is not widely used, primarily due to the risk of hypocalcaemia. We studied citrate and calcium kinetics to better understand safety aspects of this anticoagulation method.
During 15 haemodialysis treatments with a calcium-free dialysis solution, citrate was infused pre-dialyser and calcium was substituted post-dialyser. Systemic and extracorporeal citrate and calcium concentrations were repeatedly measured to calculate citrate and calcium pharmacokinetics.
Removal by dialysis constituted the major elimination pathway of citrate (83 +/- 5%). Systemic citrate load and concentrations were low (17 +/- 7 mmol/4 h, 0.3 +/- 0.15 mmol/l). Combined use of calcium-free dialysate and citrate infusion increased diffusible calcium to 80% of total calcium and induced substantial dialytic loss of calcium (43 +/- 4 mmol/4 h). Since calcium was substituted, systemic calcium balances were positive (approximately +5 mmol) and concentrations stable. Calcium supplementation correlated with calcium dialytic losses, which in turn were dependent on total calcium and haematocrit.
When using calcium-free dialysate during citrate anticoagulation, hypocalcaemia is very likely unless calcium is re-infused, because large amounts of calcium are lost in the dialysate. However, an accumulation of citrate in the patient's systemic circulation is an unlikely cause of hypocalcaemia since most of the citrate is removed by dialysis. Calcium substitution and monitoring are the most important safety measures. We propose a rational approach based on haematocrit and total calcium for the choice of the starting calcium supplementation rate.
局部枸橼酸盐抗凝是一种非常有效的血液透析抗凝方法。然而，它并未得到广泛应用，主要是由于存在低钙血症风险。我们研究了枸橼酸盐和钙的动力学，以更好地了解这种抗凝方法的安全性。
在15次使用无钙透析液的血液透析治疗过程中，在透析器前输注枸橼酸盐，并在透析器后补充钙。反复测量全身和体外的枸橼酸盐和钙浓度，以计算枸橼酸盐和钙的药代动力学。
透析清除是枸橼酸盐的主要消除途径（83±5%）。全身枸橼酸盐负荷和浓度较低（17±7 mmol/4 h，0.3±0.15 mmol/l）。联合使用无钙透析液和枸橼酸盐输注使可扩散钙增加至总钙的80%，并导致大量钙通过透析丢失（43±4 mmol/4 h）。由于补充了钙，全身钙平衡为正值（约+5 mmol）且浓度稳定。钙补充量与透析钙丢失相关，而透析钙丢失又取决于总钙和血细胞比容。
在枸橼酸盐抗凝期间使用无钙透析液时，除非重新输注钙，否则很可能发生低钙血症，因为大量钙在透析液中丢失。然而，患者全身循环中枸橼酸盐的蓄积不太可能是低钙血症的原因，因为大部分枸橼酸盐通过透析被清除。钙补充和监测是最重要的安全措施。我们基于血细胞比容和总钙提出了一种合理的起始钙补充率选择方法。
