连续性肾脏替代治疗体外抗凝时监测外周离子钙浓度最佳采血点的临床研究

Clinical research on optimal blood collection sites by determination of peripheral ionized calcium concentration in anticoagulation of continuous renal replacement therapy extracorporeal

目的探讨连续性肾脏替代治疗(CRRT)患者枸橼酸抗凝时不同采血点监测的离子钙浓度与抗凝有效性的靶浓度之间的差异,为临床提供最佳采血点的科学依据。方法以华中科技大学同济医学院附属协和医院重症医学科中采用4%枸橼酸抗凝方式的CRRT治疗患者作为研究对象,所有CRRT治疗的患者均采用Prisma-FlexV8CRRT机型及科室自配无钙配方的置换液和透析液进行治疗。根据患者实际病情治疗需求,将患者分为连续性静-静脉血液滤过(CVVH)组10例和连续性静-静脉血液透析(CVVHD)组30例。2组患者分别在CRRT治疗开始后2、4、8、14、20 h同时在滤器前和滤器后的专用体外离子钙浓度监测的采血点进行采血进行离子钙的浓度检测。为了枸橼酸抗凝的有效性,体外离子钙靶浓度目标值为0.2~0.4 mmol/L。结果纳入的40例患者在治疗过程中,共收集了400个检测结果,CVVH组共收集100个检测结果,CRRT治疗后2、4、8、14、20 h,滤器前和滤器后离子钙浓度比较差异无统计学意义(P>0.05)。CVVHD组共收集300个检测结果,CRRT治疗后2、4、8、14、20 h,滤器前离子钙浓度分别为(0.53±0.01)、(0.50±0.01)、(0.52±0.01)、(0.53±0.01)、(0.53±0.02)mmol/L,滤器后分别为(0.41±0.01)、(0.40±0.01)、(0.39±0.02)、(0.41±0.01)、(0.40±0.01)mmol/L,差异有统计学意义(t值为75.24~103.41,P<0.01)。结论CRRT治疗患者在采用枸橼酸抗凝方式时,不同的CRRT治疗模式,滤器前和滤器后的采血点采集的标本结果并不能同时准确反映枸橼酸抗凝有效性来保证体外循环管路及滤器安全使用。在CVVH治疗模式下,滤器前和滤器后的采血点所采得血检测出的钙离子浓度均可以准确反映枸橼酸的抗凝有效性;在CVVHD治疗模式下,建议在滤器前的采血点进行采血检测,有利于临床上对枸橼酸抗凝有效性的判断。

Objective To investigate the difference between the concentration of the peripheral ionized calcium(iCa)monitored at different blood collection points and the target concentration of anticoagulant efficacy in patients with continuous renal replacement therapy(CRRT),so as to provide scientific basis for the best blood collection point in clinical practice.Methods Taking patients of department of critical care medicine,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology receiving CRRT therapy with 4%citrate anticoagulation as research objects.Type of Prisma-FlexV8CRRT as well as department self-made substituate and dialyzate were adopted for all patients receiving CRRT therapy.Patients were divided into continuous veno-venous hemofiltration(CVVH)group(n=10)and continuous veno-venous hemodialysis(CVVHD)group(n=30)depending on their actual conditions and treatment needs.Blood collection was conducted at specific sites for extracorporeal peripheral ionized calcium concentration determination before and after the filter at the time of 2,4,8,14,20 hours following CRRT therapy for patients from both groups.Target concentration of extracorporeal peripheral ionized calcium was set as 0.2-0.4mmol/L for ensuring the efficacy of extracorporeal citrate anticoagulation.Results Totally 400 testing results were obtained from 40 included patients during their treatment.In CVVH group,100 testing results were obtained at the time of 2,4,8,14,20 hours following CRRT therapy and no significant statistical difference was shown(P>0.05).In CVVHD group,300 testing results were obtained at the time of 2,4,8,14,20 hours following CRRT therapy.The iCa concentration before the filter were(0.53±0.01),(0.50±0.01),(0.52±0.01),(0.53±0.01),(0.53±0.02)mmol/L while the iCa concentration after the filter were(0.41±0.01),(0.40±0.01),(0.39±0.02),(0.41±0.01),(0.40±0.01)mmol/L accordingly,and the difference was statistically significant(t values were 75.24-103.41,P<0.01).Conclusions For patients receiving CRRT treatment with citrate anticoagulation in different CRRT mode,testing results obtained from blood collection sites before and after the filter could not reflect the efficacy of citrate anticoagulation correctly and simultaneously to ensure the secure use of the extracorporeal pipelines and filter.In CVVH mode,iCa concentration determined from blood samples collected from sites before and after the filter could refelct the efficacy of citrate anticoagulation equally,while in CVVHD mode,blood collection and determination are suggested to conduct at the site before the filter to faciliate the assessment of the citrate anticoagulation efficacy.