Abstract
Acute renal failure frequentry ocurres after prolonged extracorporeal circuration or low flow perfusion. Under moderate hypothermic cardiopulmonary bypass, renal blood flow and glomerular filtration rate are decareased, and all of the glomerular filtrate is reabsorbed in tublues. It is possible that the process of tubular necrosis is developed by the influence of the decrease of urinary flow through tubules. We think that maintenance of urinary flow protects the tubules from degeneration and necrosis, The reabsorption of glomerular filtrate in tubules is inhibited by profound hypothermia which inhibits the enzymic activities at renal tubules. When prolonged extracorporeal circnlation will be unavoidable, urinary flow must be maintained by profound hypothermia about 25°C on rectal temperature, purfusing blood volume of 50-60ml/min/kg of body weight, 2.0-2.21/min/m2 of body surface area.
