[Studies on the extracorporeal circulation. Especially on changes in acid-base balance, serum electrolytes and S-GOT during rapid perfusion cooling (author's transl)].

Experiments were made using 47 mongrel dogs under normo-and hypothermic perfusion employing the DeWall-Lillehei and Kay-Cross oxygenator. The purpose of this study is to find the ideal method of extracorporeal circulation as an adjunct of cardiac surgery. In this report, the changes of acid-base balance, serum electrolytes and S-GOT during perfusion were investigated. The results obtained were as follows. 1) In spite of the hypothermia, the changes of pH and buffer base in 10 degrees C hypothermic circulatory arrest indicated the gradual progress of the tissue metabolism. After the circulation restarted uncompensated metabolic acidosis without decrease of H2CO3 ensued. The circulatory arrest for 30 minutes in 10 degrees C hypothermia was thought to be hazardous to the preservation of life. 2) In case of ventricular fibrillation, hyperkalemia in the systemic venous blood was often found. It was also observed in the coronary venous blood. In accordance with the fact of hyperkalamia during anoxia, it is presumed that the cardiac anoxia is the important factor for the development of ventricular fibrillation. 3) The value of S-GOT in the arterial blood was not influenced by perfusion time, cardiac arrest and temperature, so far as the perfusion was performed smoothly. S-GOT was elevated when cardiotomy was carried out.