[Cardiopulmonary-bypass and myocardial protection in warm heart surgery]

Eighteen cases had successful heart surgery (correction of congenital cardiac deformity in 6, valve replacement in 7, and CABG in 5) with normothermic cardiopulmonary-bypass. The main characteristics of warm heart surgery include normothermic perfusion for keeping the body temperature in normal range, that is core temperature at 35-37 degrees C, and arresting the heart by continuous administration of warm oxygenated blood cardioplegia. The cardioplegia was composed of 1 portion of high-potassium crystalloid solution and 4 portions of oxygenated blood. The crystalloid solution was St. Thomas solution adding some Kcl to make the potassium concentration at 80 or 40mmol/L. In the 18 cases, 17 hearts returned beating from arresting spontaneously, but 2 hearts had resuscitation delayed because of hyperkalemia. There were no low output syndrome, serious cardiac arrhythmia and operative death. No myocardial ischemic and reperfusion periods were noted in warm heart surgery so ischemic/reperfusion injury could be almost eliminated. However there were too much blood in the operative field and hyperkalemia tendency.