Studies on Tolerance to Prolonged Deep Hypothermia

摘要

The advantages of hypothermia, below 10 C for two hours, induced and maintained by extracorporeal circulation of 200 minutes were compared to partial bypass of the same duration during normothermia. In the normothermic group 5 of 6 dogs lived. In the hypothermic group 6 of 15 dogs (40 per cent) survived when perfused to the high flow of 55 cc/kg/min. Eleven of 15 dogs (73 per cent) survived when the flow rate was reduced to 20 cc/kg/min when the temperature was below 10 C. Metabolic data showed that no severe acidosis was present postoperatively in any group, and especially in the low flow group. The mortality was due to postperfusion lung syndrome even when low pressure was maintained in the left auricular chamber during perfusion. These findings are discussed and justify the use of low flow hypothermia during long lasting perfusion. (Author)