Cardoso P F, Yamazaki F, Keshavjee S, Schaefers H J, Hsieh C M, Wang L S, Glynn M F, Patterson G A, Cooper J D
Division of Thoracic Surgery, Toronto General Hospital, Ontario, Canada.
J Thorac Cardiovasc Surg. 1991 Jan;101(1):153-60.
We wished to determine if reduction in the standard heparin administration for cardiopulmonary bypass could be accomplished safely with the use of membrane oxygenators. An experimental study was designed to evaluate two different heparin administration protocols for cardiopulmonary bypass with hollow-fiber membrane oxygenators. Two groups of six pigs were submitted to hypothermic cardiopulmonary bypass (28 degrees C) for 3 hours, then rewarmed, decannulated, and reassessed after 1 hour. In group I (control) heparin was administered to maintain the activated clotting time in excess of 450 seconds; in group II activated clotting time was maintained between 250 and 300 seconds. The mean total heparin administered was 41,000 units in group I and 25,000 units in group II. Concentration of coagulation factors II, V, and VIII, fibrinogen, and platelet count were determined before, during, and 1 hour after bypass. No significant difference in any of these coagulation parameters was observed between the groups. The performance of the oxygenators was similar in both groups, with no evidence of thrombosis. Thus reduced heparin administration, enough to keep activated clotting time between 250 and 300 seconds, was not related either to major coagulation factors and platelet consumption or to derangements in the oxygenator's performance.
我们希望确定在使用膜式氧合器的情况下，是否能够安全地减少体外循环中标准肝素的用量。设计了一项实验研究来评估使用中空纤维膜式氧合器进行体外循环时的两种不同肝素给药方案。两组各六头猪接受低温体外循环（28摄氏度）3小时，然后复温、拔除插管，并在1小时后重新评估。在第一组（对照组）中，给予肝素以维持活化凝血时间超过450秒；在第二组中，活化凝血时间维持在250至300秒之间。第一组平均给予的肝素总量为41,000单位，第二组为25,000单位。在体外循环前、期间和后1小时测定凝血因子II、V和VIII、纤维蛋白原的浓度以及血小板计数。两组之间在任何这些凝血参数上均未观察到显著差异。两组氧合器的性能相似，没有血栓形成的迹象。因此，减少肝素用量至足以使活化凝血时间维持在250至300秒之间，与主要凝血因子和血小板消耗或氧合器性能紊乱均无关。
