The large numbers of patients who have successfully undergone surgery utilizing various combinations of extracorporeal circulation and hypothermia testify to the efficacy of the combination of these techniques. The addition of hypothermia has led to lowered tissue metabolic demands, and thus, perfusion at relatively low flows or circulatory arrest has seemed practical. However, recent clinical reports1,2 and experimental studies3-5 suggest that hypothermia may not provide as large a margin of safety in preventing tissue damage when low-flow perfusion or circulatory arrest are used as had been previously hoped.
Recently Brown et al. reported their experience with combined deep hypothermia and extracorporeal circulation in dogs. These authors were particularly interested in the neurologic status and pathologic findings in dogs surviving perfusion. It was noted that a majority of dogs who survived low-flow perfusion with deep hypothermia developed a characteristic neurologic syndrome. The major features were hind leg weakness or
WHALEN RE, BROWN IW, SMITH WW, McINTOSH HD, MARGOLIS G. Perfusion Hypothermia Studies in DogsCinefluorographic and Hemodynamic Studies. Arch Surg. 1963;86(1):118-125. doi:10.1001/archsurg.1963.01310070120016