Supplementary Material for: Impact of No Anticoagulation, Citrate Anticoagulation, and Heparin Anticoagulation on CRRT Outcomes in Patients with Hyperlactatemia: A Retrospective Cohort Study

Introduction
Continuous renal replacement therapy (CRRT) is one of the most critical interventions in the intensive care unit (ICU), and anticoagulation is essential to ensure its efficacy. Regional citrate anticoagulation (RCA) has been widely adopted in clinical practice due to its reduced risk of bleeding complications. However, the suitability of RCA for CRRT in patients with hyperlactatemia remains controversial.
Methods
This study aimed to evaluate the efficacy and safety of different anticoagulation strategies (heparin systemic anticoagulation, RCA, and no anticoagulation) during CRRT in critically ill patients with hyperlactatemia. Using a retrospective cohort design, we analyzed clinical data from the MIMIC-IV v3.0 database, employing propensity score matching (PSM) and multivariable Cox regression models to adjust for confounding factors.
Results
Our findings demonstrated that compared to the no-anticoagulation group, the citrate group exhibited significantly lower 28-day, 60-day, and 90-day mortality risks, with hazard ratios (HRs) of 0.623, 0.650, and 0.657, respectively. In contrast, the heparin group showed a significant reduction only in 28-day mortality risk (HR = 0.625). These results were further validated in the matched cohort, indicating that RCA significantly improves clinical outcomes and reduces mortality in hyperlactatemia patients requiring CRRT.
Conclusion
In summary, our study indicates that citrate anticoagulation significantly improves the prognosis of CRRT in patients with hyperlactatemia, suggesting its potential as a preferred anticoagulation strategy in this clinical setting.

引言
连续肾脏替代治疗（continuous renal replacement therapy, CRRT）是重症监护病房（intensive care unit, ICU）中最为关键的临床干预手段之一，而抗凝治疗是保障其治疗有效性的核心环节。区域性枸橼酸抗凝（regional citrate anticoagulation, RCA）因可降低出血并发症风险，已在临床实践中得到广泛应用。然而，高乳酸血症患者接受CRRT时采用RCA的适宜性仍存在争议。
方法
本研究旨在评估高乳酸血症重症患者行CRRT期间，不同抗凝策略（全身性肝素抗凝、区域性枸橼酸抗凝及无抗凝）的有效性与安全性。本研究采用回顾性队列研究设计，对MIMIC-IV v3.0数据库中的临床数据进行分析，并通过倾向得分匹配（propensity score matching, PSM）及多变量Cox回归模型校正混杂因素。
结果
本研究结果显示，与无抗凝组相比，枸橼酸抗凝组患者的28天、60天及90天死亡风险均显著降低，风险比（hazard ratios, HRs）分别为0.623、0.650及0.657。与之相对，肝素组仅在28天死亡风险上呈现显著降低（HR = 0.625）。上述结果在匹配队列中得到进一步验证，表明区域性枸橼酸抗凝可显著改善需行CRRT的高乳酸血症患者的临床结局，降低其死亡率。
结论
综上，本研究表明区域性枸橼酸抗凝可显著改善高乳酸血症患者行CRRT的预后，提示该策略有望成为此类临床场景下的首选抗凝方案。