Department of Critical Care Medicine, Jinhua Central Hospital, 351# Mingyue Road, Jinhua 321000, Zhejiang, China.
Intensive Care Med. 2012 Jan;38(1):20-8. doi: 10.1007/s00134-011-2438-3. Epub 2011 Nov 29.
Regional citrate anticoagulation (RCA) is an attractive anticoagulation mode in continuous renal replacement therapy (CRRT) because it restricts the anticoagulatory effect to the extracorporeal circuit. In recent years, several randomized controlled trials have been conducted to investigate its superiority over other anticoagulation modes. Thus, we performed a systematic review of available evidence on the efficacy and safety of RCA.
A systematic review of randomized controlled trials investigating the efficacy and safety of RCA was performed. PubMed, Current Contents, CINAHL, and EMBASE databases were searched to identify relevance articles. Data on circuit life span, bleeding events, metabolic derangement, and mortality were abstracted. Mean difference was used for continuous variables, and risk ratio was used for binomial variables. The random effects or fixed effect model was used to combine these data according to heterogeneity. The software Review Manager 5.1 was used for the meta-analysis.
Six studies met our inclusion criteria, which involved a total of 658 circuits. In these six studies patients with liver failure or a high risk of bleeding were excluded. The circuit life span in the RCA group was significantly longer than that in the control group, with a mean difference of 23.03 h (95% CI 0.45-45.61 h). RCA was able to reduce the risk of bleeding, with a risk ratio of 0.28 (95% CI 0.15-0.50). Metabolic stability (electrolyte and acid-base stabilities) in performing RCA was comparable to that in other anticoagulation modes, and metabolic derangements (hypernatremia, metabolic alkalosis, and hypocalcemia) could be easily controlled without significant clinical consequences. Two studies compared mortality rate between RCA and control groups, with one reported similar mortality rate and the other reported superiority of RCA over the control group (hazards ratio 0.7).
RCA is effective in maintaining circuit patency and reducing the risk of bleeding, and thus can be recommended for CRRT if and when metabolic monitoring is adequate and the protocol is followed. However, the safety of citrate in patients with liver failure cannot be concluded from current analysis. The metabolic stability can be easily controlled during RCA. Survival benefit from RCA is still controversial due to limited evidence.
局部枸橼酸抗凝（RCA）是一种有吸引力的连续肾脏替代治疗（CRRT）抗凝方式，因为它将抗凝作用限制在体外回路中。近年来，已经进行了几项随机对照试验来研究其优于其他抗凝方式的优势。因此，我们对 RCA 的疗效和安全性的现有证据进行了系统评价。
对 RCA 疗效和安全性的随机对照试验进行了系统评价。检索了 PubMed、Current Contents、CINAHL 和 EMBASE 数据库以确定相关文章。提取了关于回路寿命、出血事件、代谢紊乱和死亡率的数据。对于连续变量使用均数差，对于二项变量使用风险比。根据异质性，使用随机效应或固定效应模型来组合这些数据。使用 Review Manager 5.1 软件进行荟萃分析。
符合纳入标准的研究有 6 项，共涉及 658 个回路。在这 6 项研究中，排除了肝功能衰竭或出血高风险的患者。RCA 组的回路寿命明显长于对照组，平均差为 23.03 小时（95%CI 0.45-45.61 小时）。RCA 能够降低出血风险，风险比为 0.28（95%CI 0.15-0.50）。进行 RCA 时的代谢稳定性（电解质和酸碱稳定性）与其他抗凝方式相当，代谢紊乱（高钠血症、代谢性碱中毒和低钙血症）可以很容易地控制，没有明显的临床后果。两项研究比较了 RCA 组和对照组的死亡率，一项研究报告死亡率相似，另一项研究报告 RCA 优于对照组（风险比 0.7）。
RCA 可有效维持回路通畅，降低出血风险，因此如果代谢监测充分且遵循方案，可推荐在 CRRT 中使用。然而，目前的分析无法得出枸橼酸在肝功能衰竭患者中的安全性结论。在 RCA 期间可以很容易地控制代谢稳定性。由于证据有限，RCA 的生存获益仍存在争议。
