Dewhirst Elisabeth, Winch Peter, Naguib Aymen, Galantowicz Mark, Tobias Joseph D
Department of Anesthesiology & Pain Medicine, Nationwide Children's Hospital and Ohio State University, 700 Children's Drive, Columbus, OH 43205, USA.
Pediatr Cardiol. 2013 Jan;34(1):75-80. doi: 10.1007/s00246-012-0389-2. Epub 2012 Jun 1.
Preoperative phlebotomy can minimize the need for allogenic blood products. Frequently, removed blood is replaced with intravenous fluids to maintain euvolemia (acute normovolemic hemodilution [ANH]). During cardiopulmonary bypass (CPB), ANH may present problems when the circuit prime causes further hemodilution and unacceptably low hemoglobin. This investigation aimed to demonstrate that minimum volume replacement after preoperative phlebotomy can be used safely when guided by cerebral oxygenation (rSO(2)) measured by near-infrared spectroscopy (NIRS). This prospective study included patients undergoing surgery for congenital heart disease. After preoperative phlebotomy, fluid replacement was guided by mean arterial pressure (MAP), heart rate, and rSO(2), which were measured at baseline, immediately after phlebotomy, and 15 and 30 min after phlebotomy. This study enrolled 38 patients ages 3 months to 50 years. Preoperative phlebotomy removed 9.3 ± 2.9 mL/kg of blood, and 5.6 ± 5.1 mL/kg of crystalloid was administered intraoperatively. Within 30 min after phlebotomy, 23 patients had a MAP decrease of 20 % or more from baseline. This fall in MAP coincided with a decrease in rSO(2) of 20 or more at 2 of 114 measured points. Initially, rSO(2) decreased from 74 ± 9 to 68 ± 10 but thereafter remained constant. On five occasions, rSO(2) decreased 20 or more from baseline, but no patient's NIRS value was less than 45. A decrease in rSO(2) occurred more commonly in younger patients and those who had a larger volume of blood removed. Preoperative phlebotomy without significant volume replacement can be performed safely before CPB. Volume replacement may be more appropriately guided by rSO(2) than by hemodynamic variables.
术前放血可减少对异体血制品的需求。通常，放出的血液会用静脉输液来补充以维持血容量正常（急性等容血液稀释[ANH]）。在体外循环（CPB）期间，当体外循环预充液导致进一步血液稀释且血红蛋白降至不可接受的低水平时，ANH可能会引发问题。本研究旨在证明，在近红外光谱（NIRS）测量的脑氧饱和度（rSO₂）的指导下，术前放血后采用最小量的液体补充是安全可行的。这项前瞻性研究纳入了接受先天性心脏病手术的患者。术前放血后，根据平均动脉压（MAP）、心率和rSO₂来指导液体补充，这些指标在基线、放血后即刻、放血后15分钟和30分钟进行测量。本研究共纳入了38例年龄在3个月至50岁之间的患者。术前放血放出了9.3±2.9 mL/kg的血液，术中给予了5.6±5.1 mL/kg的晶体液。放血后30分钟内，23例患者的MAP较基线下降了20%或更多。MAP的这种下降与114个测量点中的2个点rSO₂下降20或更多相吻合。最初，rSO₂从74±9降至68±10，但此后保持稳定。有5次，rSO₂较基线下降了20或更多，但没有患者的NIRS值低于45。rSO₂下降在年轻患者和放血量较大的患者中更常见。在CPB前可以安全地进行术前放血且无需大量液体补充。与血流动力学变量相比，rSO₂可能更适合指导液体补充。
