Relative blood volume monitoring in hemodialysis patients: identifying its appropriate role.
Relative blood volume monitoring in hemodialysis patients: identifying its appropriate role.
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血液透析患者的相对血容量监测：确定其适当的作用。
DOI：
10.1093/ndt/gfy368
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
VanBuren,PeterNoel
中科院分区：
文献类型：
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作者：
VanBuren,PeterNoel
与普通人群相比，终末期肾病(ESRD)仍然是一种具有压倒性死亡风险的诊断，细胞外容量过剩(ECV)被认为是导致这种联系的主要因素。无论是定义相对于生化标记物如利钠肽水平的ECV过剩，还是使用生物阻抗谱(BIS)非侵入性容量测量，客观确定为相对ECV过剩的受试者与客观确定为更正常血容量的受试者相比存活率降低[1，2]。透析提供商面临的主要挑战是平衡液体清除不足和慢性ECV过剩的风险与在受限时间内清除过多液体的风险，从而导致症状或血流动力学不稳定。与过快超滤(13毫升/公斤/小时)或透析中低血压(收缩压为90毫米汞柱)相关的死亡率[3，4]值得在处方超滤时谨慎考虑。不幸的是，目前还没有具体的指导方针来指导这一人群的体液管理。虽然大幅延长透析时间是一个合理的解决方案，但后勤和患者对此的接受可能会阻碍此类策略的成功大规模实施[5]。在当前的临床实践环境中，两个重要的未解问题是：(I)我们如何识别临床上显著的ECV过剩；(Ii)我们如何安全地治疗ECV过剩？在本期《肾脏透析移植》杂志中，作者介绍了一组中等大小的维持性血液透析(HD)患者的数据，显示了在透析每小时测量的相对血容量(RBV)范围与死亡率之间的关系。这项研究的发现为RBV的预后信息提供了重要的证实，也揭示了新的数据，可能会被用来更好地处理液体管理困境。应该强调的是，即使有了这些调查结果，也只解决了两个核心问题中的一个。如何安全地处理ECV过剩的问题仍然没有答案。根据最近其他研究的数据，这个问题可能需要更个性化的方法，考虑到广泛的患者因素。在这一期中，Preciado等人报告了对800多名普遍存在的维持性HD患者的研究结果。在招募受试者的透析单位，RBV监测已作为护理标准。因此，研究人员能够确定每个受试者在6个月基准期内的平均RBV。除了计算整个透析过程中的RBV斜率外，还有关于透析治疗每小时RBV相对于基线的百分比的数据。在中位数近30个月的随访中，30%的研究对象死亡。最初的分析使用带有样条项的COX比例风险模型来确定RBV的有利范围，在该范围内，死亡率的风险比为1-3小时分别为93-96%(所有受试者的平均97.9%)、89-94%(所有受试者的平均94.8%)和86-92%(所有受试者的平均93.1%)。首先应该承认的是，在某种程度上，这些发现证实了先前的研究。在一项观察性研究中，Agarwal等人[7]发现，与斜率比中值陡峭的受试者相比，RBV斜率比中值平坦的受试者死亡率更高。以前的其他回顾分析表明，平坦的RBV斜率确定了ECV过剩[8，9]。当Preciado等人[6]…
End-stage renal disease (ESRD) continues to be a diagnosis that carries overwhelming mortality risk compared with the general population, and extracellular volume excess (ECV) is considered to be a major factor driving this association. Whether one is defining ECV excess relative to biochemical markers such as natriuretic peptide levels or noninvasive volume measurements using bioimpedance spectroscopy (BIS), subjects that are objectively determined to have relative ECV excess have decreased survival compared with those objectively determined to be more euvolemic [1, 2]. The primary challenge dialysis provider’s face is balancing the risk of inadequate fluid removal and chronic ECV excess with the risk of removing too much fluid during a restricted period, leading to symptoms or hemodynamic instability. The mortality associations with excessively rapid ultrafiltration (> 13 mL/kg/h) or intradialytic hypotension (nadir< 90mmHg for systolic blood pressure)[3, 4] justify cautious consideration when prescribing ultrafiltration. Unfortunately there are currently no specific guidelines to direct fluid management in this population. Although substantially lengthening dialysis time is a rational solution, the logistics and the patient’s acceptance of this might hinder successful large-scale implementation of such strategies [5]. In the current clinical practice environment, two important unanswered questions are (i) how do we identify clinically significant ECV excess and (ii) how do we safely treat ECV excess? In this issue of Nephrology Dialysis Transplantation, the authors present data from a moderate-sized cohort of maintenance hemodialysis (HD) patients showing an association between ranges of relative blood volume (RBV) measured at each hour of dialysis and mortality. The findings from this study provide important confirmation about the prognostic information from RBV and also reveal novel data that may be utilized to better approach the fluid management dilemma. It should be emphasized that even with these findings, only one of the two central questions is addressed. The question of how to safely treat ECV excess still remains unanswered. Based on the data emerging from other recent studies, this question likely requires a more individualized approach that accounts for a wide range of patient factors.In this issue, Preciado et al.[6] report findings from a cohort of more than 800 prevalent maintenance HD patients. In the dialysis units where the subjects were recruited, RBV monitoring has been implemented as the standard of care. Consequently, the investigators were able to determine the mean RBV for each subject during a 6-month baseline period. There were data on the percentage of RBV relative to baseline at each hour of the dialysis treatment in addition to a calculated slope of RBV throughout dialysis. With a median follow-up of nearly 30 months, 30% of subjects in the study died. The initial analysis utilized a Cox proportional hazards model with spline terms to identify the favorable ranges of RBV where the hazard ratio for mortality was< 1. For Hours 1–3, these were 93–96%(mean 97.9% for all subjects), 89–94%(mean 94.8% for all subjects) and 86–92%(mean 93.1% for all subjects), respectively. It should first be acknowledged that, to some extent, these findings are confirmatory of prior research. In one observational study, Agarwal et al.[7] identified that subjects whose RBV slopes were flatter than the median values had increased mortality compared with those whose slopes were steeper than the median value. Other retrospective analyses had previously shown that flat RBV slopes identified ECV excess [8, 9]. When Preciado et al.[6 …