Newman M, Munsch C, McMillan J, Slavotinek J, Rosenfeldt F L
Cardiac Surgical Research Unit, Baker Medical Research Institute, Prahran, Victoria.
Aust N Z J Surg. 1989 Apr;59(4):343-6. doi: 10.1111/j.1445-2197.1989.tb01579.x.
During open heart surgery, myocardial protection provided by oxygenated blood-based cardioplegia is superior to that provided by non-oxygenated crystalloid cardioplegia. However, the widespread use of blood cardioplegia has been limited by the cost and complexity of the associated cooling and delivery systems. The performance of a simple system--a polyethylene coil immersed in ice--has been compared with three systems incorporating specialized, water-jacketed heat exchangers: Buckberg Shiley, Shiley BCD and Bentley HE-100. Blood was diluted to a haematocrit of 22% and delivered to each cooling system at flow rates of 200-500 mL/min and temperatures of 25 degrees C and 30 degrees C. Cooling water at 0-1 degree C was supplied to the heat exchangers at flow rates of 2, 4, and 6 L/min. Performance was measured by comparing the blood outflow temperatures at the same inflow temperature under a variety of test conditions which simulated those occurring in clinical practice. All cooling systems, except the Buckberg Shiley, were able consistently to cool blood cardioplegia adequately (below 10 degrees C), but the ice coil was the most effective. The heat exchanger systems are 3-4 times more expensive than the ice coil and require an external source of cold water. Thus the ice coil system has the advantages of simplicity, efficiency, and economy.
在心脏直视手术中，含氧血液心脏停搏液提供的心肌保护优于非含氧晶体心脏停搏液。然而，血液心脏停搏液的广泛应用受到相关冷却和输送系统成本及复杂性的限制。已将一个简单系统（浸于冰中的聚乙烯盘管）的性能与三种采用专门的水套式热交换器的系统（Buckberg Shiley、Shiley BCD和Bentley HE - 100）进行了比较。血液被稀释至血细胞比容为22%，并以200 - 500 mL/分钟的流速和25摄氏度及30摄氏度的温度输送至每个冷却系统。0 - 1摄氏度的冷却水以2、4和6 L/分钟的流速供应至热交换器。通过比较在模拟临床实际情况的各种测试条件下相同流入温度时的血液流出温度来衡量性能。除Buckberg Shiley外，所有冷却系统均能始终如一地将血液心脏停搏液充分冷却（低于10摄氏度），但冰盘管是最有效的。热交换器系统比冰盘管贵3 - 4倍，且需要外部冷水源。因此，冰盘管系统具有简单、高效和经济的优点。
