背景与目的连续性肾脏替代治疗(CRRT)是治疗危重住院多器官功能障碍患者肾功能衰竭的血液净化治疗方法,有效预防尿毒症和多器官功能衰竭,同时改善肾功能。然而,通过体外循环灌注患者血液通常会导致CRRT回路或血液过滤器意外的早期阻塞,导致CRRT频繁中断和医疗资源浪费。此外,这种回路闭塞的临床研究是有限的。在日本,CRRT回路需要长期灌注,通常持续24小时或更长时间,表明需要一个能够在任何时间诱导闭塞的模型;该模型可以评估各个方面,包括原因和潜在机制,并有助于开发遮挡预测方法。因此,我们假设需要一个模型来诱导任意时间点的遮挡.因此,我们致力于开发一种离体回路闭塞模型,包括将钙注射到循环柠檬酸动物血液中,以评估氯化钙注射量之间的关系,电路闭塞时间,以及回路压力随时间的变化。方法我们使用市售的CRRT电路开发了电路闭塞模型,聚砜膜滤血器,加热管,和恒温水浴,以及市售的柠檬酸牛全血。使用滚柱泵在10分钟的持续时间内用血液填充回路,并在特定时间段后通过改变注射到牛全血中的钙的流速而闭塞。此外,在牛全血循环的同时,维持1mEq/mL氯化钙连续注射到回路中.在每个钙注射流速(2、3和4mL/h)下进行测量,每次测量执行五次。未接受钙注射的组用作对照(0mL/h:Con),实验进行了三次。对于每个钙注射流速,组定义为“0、2、3和4”。氯化钙的注入量之间的关系,电路闭塞时间,并评估回路压力随时间的变化。此外,在任意时间进行血液检查和血液粘弹性测试。结果回路闭塞时间随每次注钙流量的变化而变化,各组间差异有统计学意义(p<0.05)。以2、3和4mL/h的速度注射钙时,阻塞前4分钟回路压力逐渐变化,在闭塞前一分钟有更快的变化。我们在闭塞前4分钟和1分钟测量了回路压力(-4分钟,和-1分钟,分别),Con和4mL/h组在回路闭塞时(0分钟)。在4mL/h的钙流速下,在-4分钟和0分钟以及-1分钟和0分钟之间观察到AP的显着差异。此外,预滤器和回流压力在-4分钟和0分钟之间存在显著差异,-4分钟和-1分钟,和-1分钟和0分钟,钙流速为4毫升/小时(p<0.05)。结论我们提出的模型根据回路压力的变化准确地估计了闭塞时间。该模型可用于根据所需的闭塞时间创建各种实验系统。
Background and objective Continuous renal replacement therapy (CRRT) is a blood purification therapy modality for the treatment of renal failure in critically ill hospitalized patients with multiorgan dysfunction, effectively preventing uremia and multiple organ failure while improving renal function. However, the perfusion of patient blood through extracorporeal circulation often results in unexpected early occlusion of the CRRT circuit or hemofilter, leading to frequent interruptions in CRRT and wastage of medical resources. Moreover, clinical research on such circuit occlusions is limited. In Japan, CRRT circuits require long-term perfusion, often lasting 24 hours or more, indicating the need for a model capable of inducing occlusion at any arbitrary time; this model can evaluate various aspects, including causes and underlying mechanisms, and contribute to the development of an occlusion prediction method. Hence, we hypothesized the need for a model for inducing occlusion at arbitrary time points. Consequently, we strove to develop an ex vivo circuit occlusion model involving the injection of calcium into circulating citrated animal blood to evaluate the relationship between the amount of calcium chloride injected, circuit occlusion time, and changes in circuit pressure over time. Methods We developed a circuit occlusion model using a commercially available CRRT circuit, polysulfone membrane hemofilter, heating extension tube, and thermostatic water bath, along with commercially available citrated bovine whole blood. The circuit was filled with blood over a 10-min duration using a roller pump and was occluded after a specific period by varying the flow rate of calcium injected into bovine whole blood. Additionally, continuous injection of 1 mEq/mL calcium chloride into the circuit was maintained while bovine whole blood circulated. Measurements were performed at each calcium injection flow rate (2, 3, and 4 mL/h), with each measurement performed five times. The group that did not receive calcium injection was used as the control (0 mL/h: Con), and the experiment was performed three times. Groups were defined as \"0, 2, 3, and 4\" for each calcium injection flow rate. The relationship among the amount of calcium chloride injected, circuit occlusion time, and changes in circuit pressure over time was evaluated. Furthermore, blood tests and blood viscoelastic tests were performed at arbitrary times. Results The circuit occlusion time varied with each calcium injection flow rate, and a significant difference was observed between each group (p<0.05). Circuit pressure gradually changed at four min before occlusion when calcium was injected at 2, 3, and 4 mL/h, with a more rapid change at one min before occlusion. We measured circuit pressure at four and one min before occlusion (-4 min, and -1 min, respectively), and at the time of circuit occlusion (0 min) in the Con and 4 mL/h groups. Significant differences were observed in AP between -4 min and 0 min and -1 min and 0 min at a calcium flow rate of 4 mL/h. Additionally, significant differences were seen in prefilter and return pressures between -4 min and 0 min, -4 min and -1 min, and -1 min and 0 min at a calcium flow rate of 4 mL/h (p<0.05). Conclusions Our proposed model accurately estimated the occlusion time based on changes in circuit pressure. This model can be used to create various experimental systems depending on the desired occlusion time.