Table_1_Effect of Dynamic Circuit Pressures Monitoring on the Lifespan of Extracorporeal Circuit and the Efficiency of Solute Removal During Continuous Renal Replacement Therapy.DOCX

Objective: To observe the effects of dynamic pressure monitoring on the lifespan of the extracorporeal circuit and the efficiency of solute removal during continuous renal replacement therapy (CRRT).
Materials and Methods: A prospective observational study was performed at the West China Hospital of Sichuan University in the ICU. Analyses of the downloaded pressure data recorded by CRRT machines and the solute removal efficiencies, calculated by 2*Ce/(Cpre+Cpost), where Ce, Cpre, and Cpost are the concentrations of the effluent, pre-filter blood, and post-filter blood, respectively, were performed. Samples were collected at 0, 2, 6, 12, and 24 h when continuous veno-venous hemodiafiltration (CVVHDF) was used after the initiation of CRRT. Measurements in concentrations of creatinine, blood urea nitrogen, and β2-microglobulin in the plasma and effluent were recorded.
Results: Extracorporeal circuits characterized by moderate-to-severe (M–S) access outflow dysfunction (AOD) events, defined as access outflow pressure less than or equal to −200 mmHg for more than 5 min, had shorter median lifespans with no anticoagulation (32.3 vs. 10.90 h, P = 0.001) compared with the no M–S AOD events group. The significant outcome also existed in regional citrate anticoagulation (RCA) (72 vs. 42.47 h, P = 0.02). Moreover, Cox regression analysis revealed that the lack of M–S AOD events, RCA, or CVVHDF independently prolonged the circuit lifespan. All tested solutes removal efficiencies started to decline at 12 h. Furthermore, efficiencies of all solutes removal dropped obviously at 24 h when TMP ≥ 150 mmHg.
Conclusion: RCA and CVVHDF predicted a longer circuit lifespan. M–S AOD events were associated with a shorter circuit lifespan when RCA or no anticoagulant was used. Replacement of extracorporeal circuit could be considered when running time of filter lasted up to 24 h with TMP ≥ 150 mmHg.

研究目的：探讨动态压力监测对连续性肾脏替代治疗（continuous renal replacement therapy, CRRT）中外循环管路使用寿命及溶质清除效率的影响。
材料与方法：本研究为前瞻性观察性研究，于四川大学华西医院重症监护病房（ICU）开展。对CRRT设备记录的下载压力数据，以及采用公式2*Ce/(Cpre+Cpost)计算的溶质清除效率进行分析，其中Ce、Cpre、Cpost分别指流出液、滤器前血液及滤器后血液的浓度。在CRRT启动后采用连续性静脉-静脉血液透析滤过（continuous veno-venous hemodiafiltration, CVVHDF）模式时，于0、2、6、12及24 h时点采集样本。记录血浆及流出液中肌酐、血尿素氮及β2-微球蛋白的浓度检测结果。
研究结果：存在中重度（moderate-to-severe, M-S）通路流出功能障碍（access outflow dysfunction, AOD）事件的体外循环管路（定义为通路流出压≤-200 mmHg且持续时间超过5 min），在未使用抗凝剂时的中位使用寿命短于无M-S AOD事件组（32.3 h vs. 10.90 h，P=0.001）。该差异在采用区域性枸橼酸抗凝（regional citrate anticoagulation, RCA）的亚组中同样显著（72 h vs. 42.47 h，P=0.02）。此外，Cox回归分析显示，无M-S AOD事件、使用RCA或采用CVVHDF模式均可独立延长管路使用寿命。所有检测溶质的清除效率均在12 h时开始下降。当跨膜压（transmembrane pressure, TMP）≥150 mmHg时，所有溶质的清除效率在24 h时均出现显著下降。
研究结论：采用RCA及CVVHDF模式可预测更长的体外循环管路使用寿命。当使用RCA或未使用抗凝剂时，M-S AOD事件与管路使用寿命缩短相关。当滤器运行时长达到24 h且TMP≥150 mmHg时，可考虑更换体外循环管路。