Wang Pei-Li, Meyer Mary M, Orloff Susan L, Anderson Sharon
Division of Nephrology and Hypertension, Department of Medicine Oregon Health and Science University, Portland, OR 97239, USA.
Am J Kidney Dis. 2004 Dec;44(6):1110-4. doi: 10.1053/j.ajkd.2004.09.001.
Regional citrate anticoagulation is an alternative to heparin in patients with bleeding diatheses who require continuous renal replacement therapy (CRRT). The short-term metabolic consequences that occur with citrate anticoagulation are well described and usually manageable if established protocols are followed vigilantly. Because of its customary short-term nature, the long-term consequences of CRRT with citrate are less often considered and have not been reported. The authors present the case of a woman with multisystem organ failure and prolonged acute renal failure who required CRRT for 120 days. Throughout her hospital course, adequate regional anticoagulation was achieved by blocking the coagulation cascade via the chelation of calcium by citrate. Despite an appropriate drop in the postfilter ionized calcium level, by 8 weeks after the initiation of CRRT, the patient was able to normalize serum calcium levels without the customary calcium infusion. Bone resorption owing to prolonged immobilization leading to hypercalcemia is a known complication of critically ill patients. This problem is more pronounced in patients with high bone turnover rates owing to conditions such as secondary hyperparathyroidism. In this particular case, the chelation of calcium by citrate masked the ensuing immobilization hypercalcemia, resulting in marked bone loss and bilateral spontaneous femoral fractures in the context of normal calcium levels. In critically ill patients sustained with prolonged CRRT with citrate anticoagulation, bone resorption and "relative" immobilization hypercalcemia may manifest as normal serum calcium levels in the face of falling calcium infusion rate requirements.
对于有出血倾向且需要持续肾脏替代治疗(CRRT)的患者,局部枸橼酸盐抗凝是肝素抗凝的一种替代方法。枸橼酸盐抗凝所产生的短期代谢后果已有充分描述,并且如果严格遵循既定方案通常是可控的。由于其通常具有短期性质,枸橼酸盐CRRT的长期后果较少被考虑且尚未见报道。作者报告了一例多系统器官衰竭和长期急性肾衰竭的女性患者,她需要进行120天的CRRT。在其整个住院过程中,通过枸橼酸盐螯合钙来阻断凝血级联反应,实现了充分的局部抗凝。尽管滤器后离子钙水平适当下降,但在CRRT开始8周后,患者能够在未常规输注钙的情况下使血清钙水平恢复正常。因长期制动导致高钙血症的骨吸收是重症患者的一种已知并发症。在诸如继发性甲状旁腺功能亢进等导致高骨转换率的患者中,这个问题更为明显。在这个特殊病例中,枸橼酸盐对钙的螯合掩盖了随后出现的制动性高钙血症,导致在血钙水平正常的情况下出现明显的骨质流失和双侧自发性股骨骨折。在接受长期枸橼酸盐抗凝CRRT的重症患者中,骨吸收和“相对”制动性高钙血症可能表现为随着钙输注速率需求下降而血清钙水平正常。