Department of Surgical and Perioperative Science, Heart Centre, Umeå University Hospital, Umeå, Sweden.
Eur J Cardiothorac Surg. 2010 Jan;37(1):218-22. doi: 10.1016/j.ejcts.2009.05.019. Epub 2009 Jul 29.
Blood-flow control during cardiopulmonary bypass (CPB) is by tradition based on the patient's body surface area. Emergence of new techniques enables dynamic blood-flow control based on online measurement of venous oxygen saturation and oxygen consumption. Present investigation aimed to compare static versus dynamic blood-flow control with respect to use of oxygen and effects upon organ function.
In this study, 100 coronary-artery-bypass surgical patients were prospectively randomised to static or dynamic hypothermic blood-flow control during CPB. In the static group, pump flow was set to 2.4 (litres per minute) times the patient's body surface area (m(2)) throughout the procedure. Pump flow in the dynamic group was varied according to the reading of the venous oxygen saturation and maintained at >75%. CPB-specific information was collected online. Blood samples were collected for analysis of haemoglobin, lactate, amylase, creatinine and C-reactive protein: pre-CPB, at weaning from CPB and on day 1 postoperatively.
Randomisation formed two uniform groups. Choice of static or dynamic blood-flow control during CPB had no significant effects on organ function as judged by lactate, amylase or creatinine levels. On increasing oxygen demand, oxygen balance was maintained by increasing venous oxygen extraction rates in the static flow mode and by increasing the pump flow rate in the dynamic group.
Independent of the blood-flow control mode, oxygen balance remained preserved. However, the dynamic mode provided higher oxygen delivery, which may increase margins of safety and protection of organ function.
体外循环（CPB）期间的血流控制传统上基于患者的体表面积。新技术的出现使得基于静脉血氧饱和度和耗氧量的在线测量来实现动态血流控制成为可能。本研究旨在比较静态与动态血流控制在氧利用和器官功能影响方面的差异。
在这项研究中，100 例冠状动脉旁路手术患者前瞻性随机分为 CPB 期间采用静态或动态低温血流控制。在静态组中，整个过程中泵流量设定为患者体表面积（m²）的 2.4 倍（升/分钟）。在动态组中，根据静脉血氧饱和度的读数来调整泵流量，并保持在>75%。在线收集 CPB 特定信息。采集血样进行血红蛋白、乳酸、淀粉酶、肌酐和 C 反应蛋白分析：CPB 前、CPB 脱机时和术后第 1 天。
随机分组形成了两个均匀的组。CPB 期间选择静态或动态血流控制对器官功能（通过乳酸、淀粉酶或肌酐水平判断）没有显著影响。在增加氧需求时，静态血流模式通过增加静脉血氧摄取率，而动态组通过增加泵流量来维持氧平衡。
无论血流控制模式如何，氧平衡均保持稳定。然而，动态模式提供了更高的氧输送，这可能增加安全边际和器官功能保护。
