Álvarez Nadal Marta, Rodríguez Mendiola Nuria, Díaz Domínguez Martha Elizabeth, Fernández Lucas Milagros
Department of Nephrology, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain.
Facultad de Medicina, Universidad de Alcalá, Madrid, Spain.
Hemodial Int. 2023 Apr;27(2):184-192. doi: 10.1111/hdi.13074. Epub 2023 Feb 14.
Intradialytic hypotension (IDH) remains one of the most frequent complications associated to hemodialysis (HD), frequently triggered by a reduction in absolute blood volume (ABV) not compensated by vascular refilling. A recently developed dilutional method allows routinary measurement of ABV and, by a simple algorithm, may turn blood volume monitor (BVM) guided UF (ultrafiltration) biofeedback into an ABV control, automatically adjusting UF rate to maintain ABV above a preset threshold. The aim of this study is to identify an individual critical ABV threshold and test the ability of an ABV feedback control to avoid IDH.
We studied 24 patients throughout three consecutive midweek HD treatments. ABV and blood pressure (BP) were measured every 30 min and anytime the patient referred any symptoms to identify each patient's critical ABV (ABV at the time of hypotension). A fixed bolus dilution approach at the start of HD was used to calculate ABV. Then, patients were followed through three additional HD treatments and IDH development was analyzed.
Seventy-one treatments performed in 24 patients. ABV monitoring showed a constant decrease as HD treatment progressed. Thirteen IDH events were observed in eight different patients, with a mean systolic BP drop in IDH treatments of 37.38 ± 4.31 mmHg and a mean adjusted ABV at hypotension of 71.07 ± 14.88 mL/kg. Critical ABV was individually set in patients prone to IDH. As expected, ABV feedback control successfully maintained ABV over preset critical ABV. IDH events were avoided in 21 out of 22 treatments performed. ABV drop was successfully reduced, as well as SBP drop (despite similar UF than prior to ABV feedback control implementation).
ABV feedback control avoided IDH in 21 out of 22 treatments performed by maintaining blood volume above critical ABV, significantly reducing ABV variations without compromising prescribed UF.
透析中低血压（IDH）仍然是血液透析（HD）最常见的并发症之一，通常由绝对血容量（ABV）减少引发，且未得到血管再充盈的代偿。最近开发的一种稀释方法可常规测量ABV，并通过一个简单算法，将血容量监测器（BVM）引导的超滤（UF）生物反馈转变为ABV控制，自动调整超滤率以维持ABV高于预设阈值。本研究的目的是确定个体临界ABV阈值，并测试ABV反馈控制避免IDH的能力。
我们对24例患者进行了连续三次周中HD治疗的研究。每30分钟测量一次ABV和血压（BP），并在患者出现任何症状时随时测量，以确定每位患者的临界ABV（低血压时的ABV）。HD开始时采用固定推注稀释法计算ABV。然后，对患者进行另外三次HD治疗，并分析IDH的发生情况。
24例患者共进行了71次治疗。随着HD治疗的进行，ABV监测显示持续下降。在8例不同患者中观察到13次IDH事件，IDH治疗中平均收缩压下降37.38±4.31mmHg且低血压时平均调整后的ABV为71.07±14.88mL/kg。对易发生IDH的患者分别设定临界ABV。正如预期的那样，ABV反馈控制成功地将ABV维持在预设的临界ABV之上。在进行的22次治疗中有21次避免了IDH事件。ABV下降以及收缩压下降均成功减少（尽管超滤与实施ABV反馈控制之前相似）。
ABV反馈控制通过将血容量维持在临界ABV之上，在22次治疗中的21次避免了IDH，在不影响规定超滤量的情况下显著减少了ABV变化。
