Nephrology Department, Grigore T. Popa University of Medicine and Pharmacy, Iasi, Romania.
Clinical and Therapeutical Governance-Care Value Management, Fresenius Medical Care Deutschland, Bad Homburg, Germany.
Nephrol Dial Transplant. 2019 Aug 1;34(8):1385-1393. doi: 10.1093/ndt/gfy396.
Both baseline fluid overload (FO) and fluid depletion are associated with increased mortality risk and cardiovascular complications in haemodialysis patients. Fluid status may vary substantially over time, and this variability could also be associated with poor outcomes.
In our retrospective cohort study, including 4114 haemodialysis patients from 34 Romanian dialysis units, we investigated both all-cause and cardiovascular mortality risk according to baseline pre- and post-dialysis volume status, changes in pre- and post-dialysis fluid status during follow-up (time-varying survival analysis), pre-post changes in volume status during dialysis and pre-dialysis fluid status variability during the first 6 months of evaluation.
According to their pre-dialysis fluid status, patients were stratified in the following groups: normovolaemic with an absolute FO (AFO) compartment between -1.1 and 1.1 L, fluid depletion with an AFO below -1.1 L, moderate FO with an AFO compartment >1.1 but <2.5 L and severe FO with the AFO compartment >2.5 L. Baseline pre-dialysis FO and fluid depletion patients had a significantly elevated risk of all-cause mortality risk {hazard ratio [HR] 1.53 [95% confidence interval (CI) 1.22-1.93], HR 2.04 (95% CI 1.59-2.60) and HR 1.88 (95% CI 1.07-3.39) for moderate FO, severe FO and fluid depletion, respectively}. In contrast, post-dialysis fluid depletion was associated with better survival [HR 0.71 (95% CI 0.57-0.89)]. Similar results were found when using changes in pre- or post-dialysis fluid status during follow-up (time-varying values): FO patients had an increased risk of all-cause [moderate FO: HR 1.39 (95% CI 1.11-1.75); severe FO: HR 2.29 (95% CI 2.01-3.31] and cardiovascular (CV) mortality [moderate FO: HR 1.34 (95% CI 1.05-1.70); severe FO: HR 2.34 (95% CI 1.67-3.28)] as compared with normohydrated patients. Using pre-post changes in volume status during dialysis, we categorized the patients into six groups: Group 1, AFO <-1.1 L pre- and post-dialysis; Group 2, AFO between -1.1 and 1.1 L pre-dialysis and <-1.1 L post-dialysis (the reference group); Group 3, AFO between -1.1 and 1.1 L pre- and post-dialysis; Group 4, AFO >1.1 L pre-dialysis and <-1.1 L post-dialysis; Group 5, AFO >1.1 L pre-dialysis and between -1.1 and 1.1 L post-dialysis; Group 6, AFO >1.1 L pre- and post-dialysis. Using the baseline values, only patients in Groups 1, 5 and 6 maintained an increased risk for all-cause mortality as compared with the reference group. Additionally, CV mortality risk was significantly higher for patients in Groups 5 and 6. When we applied the time-varying analysis, patients in Groups 1, 5 and 6 had a significantly higher risk for both all-cause and CV mortality risk. In the last approach, the highest risk for the all-cause mortality outcome was observed for patients with high-amplitude fluctuation during the first 6 months of evaluation [HR 2.75 (95% CI 1.29-5.84)].
We reconfirm the association between baseline pre- and post-dialysis volume status and mortality in dialysis patients; additionally, we showed that greater fluid status variability is independently associated with higher mortality.
基线时液体超负荷（FO）和液体耗竭均与血液透析患者的死亡风险和心血管并发症增加相关。液体状态可能随时间有很大的变化，这种变化也可能与不良结局相关。
在我们的回顾性队列研究中，纳入了来自罗马尼亚 34 个透析单位的 4114 名血液透析患者，我们根据基线透析前后的容量状态、随访期间透析前后液体状态的变化（时间变化的生存分析）、透析过程中容积状态的变化以及评估的前 6 个月内的液体状态变异性来研究全因和心血管死亡率风险。
根据他们的透析前液体状态，患者被分为以下几组：绝对 FO（AFO）容积在-1.1 至 1.1 L 之间的正常血容量、AFO 容积低于-1.1 L 的液体耗竭、AFO 容积大于 1.1 但小于 2.5 L 的中度 FO 和 AFO 容积大于 2.5 L 的严重 FO。基线透析前 FO 和液体耗竭患者的全因死亡率风险显著升高[危险比（HR）1.53（95%置信区间[CI] 1.22-1.93），HR 2.04（95% CI 1.59-2.60）和 HR 1.88（95% CI 1.07-3.39）分别为中度 FO、严重 FO 和液体耗竭]。相比之下，透析后液体耗竭与更好的生存相关[HR 0.71（95% CI 0.57-0.89）]。当使用随访期间透析前后液体状态的变化（时间变化的值）时，也得到了相似的结果：FO 患者的全因[中度 FO：HR 1.39（95% CI 1.11-1.75）；严重 FO：HR 2.29（95% CI 2.01-3.31]和心血管（CV）死亡率[中度 FO：HR 1.34（95% CI 1.05-1.70）；严重 FO：HR 2.34（95% CI 1.67-3.28）]风险增加，与正常血容量患者相比。使用透析过程中容积状态的前后变化，我们将患者分为六组：组 1，透析前后 AFO <-1.1 L；组 2，透析前 AFO 在-1.1 至 1.1 L 之间，透析后 AFO <-1.1 L（参考组）；组 3，透析前后 AFO 在-1.1 至 1.1 L 之间；组 4，透析前 AFO >1.1 L，透析后 AFO <-1.1 L；组 5，透析前 AFO >1.1 L，透析后 AFO 在-1.1 至 1.1 L 之间；组 6，透析前和透析后 AFO >1.1 L。使用基线值，仅组 1、组 5 和组 6 的患者与参考组相比，全因死亡风险增加。此外，组 5 和组 6 的患者 CV 死亡率风险显著更高。当我们应用时间变化分析时，组 1、组 5 和组 6 的患者全因和 CV 死亡率风险显著增加。在最后一种方法中，评估的前 6 个月内高幅度波动的患者的全因死亡率结局风险最高[HR 2.75（95% CI 1.29-5.84）]。
我们再次证实了透析患者透析前后容量状态与死亡率之间的关联；此外，我们还表明，更大的液体状态变异性与更高的死亡率独立相关。
