Clinical studies of hypothermic perfusion by the hemodilution technique, especially its influence on water and electrolytes changes, and renal function.

Hypothermic low flow cardiopulmonary bypass with hemodilution technique was performed in open-heart surgery in the author's clinic. To evaluate the usefulness of this perfusicn, renal hemodynamics during total bypass, and its influence on renal function were studied. The average effective renal blood flow during total bypass at the perfusion rate of 50 to 60 ml per kg per minute under mild or moderate hypothermia was 7.7 ml per kg per minute. Osmolality, blood urea nitrogen, free plasma hemoglobin, electrolytes and urea excretion and urinary output were studied for evaluating the postoperative renal function. Osmolality was one of the most convenient indicator of predicting renal insufficiency. It was concluded that the hypothermic perfusion with hemodilution technique was a commendable method in carrying out complicated intracardiac procedure.