Harostock Michael, Filler Joseph J, Burak David A, McDonnell Bryan E, Emilcar Jean, Torres Albert, Zimak Joseph, Patel Twinkle, Harostock Michael D
The Pennsylvania State University, Wilkes-Barre, Pennsylvania, USA.
Heart Surg Forum. 2008;11(3):E188-92. doi: 10.1532/HSF98.20071162.
Hemodilution is a well-recognized phenomenon of cardiopulmonary bypass (CPB). The degree of hemodilution has attendant risks. As the degree of hemodilution increases, red blood cell transfusions may be necessary, and the risks of blood transfusions are becoming very well recognized. Blood-conservation programs are being developed worldwide to establish strategies to reduce transfusions. Miniaturized extracorporeal circuits (MECs) are associated with less hemodilution than conventional CPB circuits. The use of MECs can be expected to be associated with fewer red blood cell transfusions.
The first 250 patients who underwent coronary artery bypass grafting, aortic valve replacement, or both with the use of a MEC were compared with 200 consecutive patients who had similar comorbidities and types of surgery but underwent their operations on a conventional bypass circuit. These surgeries were completed between April 2004 and September 2005 under the care of the same surgical team. The minimum acceptable hematocrit on bypass was 22%. Intra- and postoperative transfusion rates were measured and compared.
For conventional bypass, the intraoperative transfusion rate was 36.5%, whereas the rate for the MEC was 23.3%. The postoperative transfusion rate was 55% for operations performed with conventional bypass and 26% for the MEC. The overall in-hospital transfusion rate for conventional bypass was 63% and 36% for the MEC.
The data indicate that use of MECs leads to a lower transfusion rate than in surgeries in which conventional CPB is used.
血液稀释是体外循环（CPB）中一种公认的现象。血液稀释程度存在相应风险。随着血液稀释程度增加，可能需要输注红细胞，而输血风险也已得到充分认识。全球正在制定血液保护计划，以建立减少输血的策略。与传统CPB回路相比，小型体外循环回路（MEC）引起的血液稀释较少。预计使用MEC可减少红细胞输注。
将首批250例使用MEC进行冠状动脉搭桥术、主动脉瓣置换术或两者兼有的患者，与200例具有相似合并症和手术类型但在传统旁路回路上进行手术的连续患者进行比较。这些手术于2004年4月至2005年9月在同一手术团队的护理下完成。体外循环时的最低可接受血细胞比容为22%。测量并比较术中及术后输血率。
对于传统旁路手术，术中输血率为36.5%，而MEC手术的输血率为23.3%。传统旁路手术的术后输血率为55%，MEC手术为26%。传统旁路手术的院内总体输血率为63%，MEC手术为36%。
数据表明，与使用传统CPB的手术相比，使用MEC可降低输血率。
