232 INFLUENCE OF TEMPERATURE ON BIOLOGICAL SYSTEMS 



advanced carcinoma of the cervix in which pain was so severe that 

 chordotomy had been advised. Within 36 hours of treatment with circu- 

 lating water at 5° to 10°C all pain had disappeared, and at the end of six 

 weeks the lesion was healed and the woman was able to return home. 

 Several months later she died from a brain metastasis. Subsequently, 

 Fay and Henny applied local hypothermia successfully for cancers of 

 the breast, cheek and skin. In 1940 Fay (64) reported that results of 

 generalized hypothermia in more than 100 cancer patients adjudged 

 hopeless cases. Body temperatures were reduced to between 32°C and 23°C 

 and cooling was maintained as long as eight days. Although freedom 

 from pain during the treatment was universal, it was not permanent, and 

 regression of the tumors was not demonstrated in this series. In other 

 reports (70, 181, 178) no evidence was found of tumor regression with 

 similar treatment (134). It was unfortunate that these early attempts 

 to utilize generalized hypothermia were not preceded by a more complete 

 study of the effects of low body temperatures. With the reports of deaths 

 during the induction of hypothermia, its hazards were magnified and 

 acceptance by the medical profession was delayed. Likewise, in attempts 

 to use 'crymotherapy' for the entire body, a fact of importance was over- 

 looked. In the earliest and most successful cases, temperatures from 5° 

 to 10°C were used; however, when generalized hypothermia was employed 

 the lowest temperatures which could be achieved were 20°C higher. It 

 appears possible that the differences in success of the two treatments may 

 well be attributed to these great differences in temperature utilized. 



General acceptance of hypothermia as a useful tool in the operating 

 room awaited the studies of Bigelow and co-workers in 1950 (32, 33). 

 Since these provided some of the necessary physiological experimentation 

 which was lacking previously, interest in the field was re-aroused and has 

 been on the increase ever since. They demonstrated that with dogs 

 anesthetized to prevent shivering, oxygen consumption changed in a linear 

 fashion with temperature, decreasing during cooling and increasing during 

 rewarming. At 20°C the dogs' oxygen requirements were found to be only 

 18% of normal and by extrapolation it was calculated that at temperatures 

 between 10° and 12°C the metabolism would be practically nil. In addition, 

 they demonstrated that circulation could be stopped for 15 minutes and 

 the heart opened with complete recovery. Since then most of the research on 

 hypothermia has been carried on by people interested in cardiac surgery 

 (36, 45, 46, 98, 99, 73, 76, 77, 175-177, 104, 29, 133, 72, 27) . 



PHYSIOLOGY OF HYPOTHERMIA 



Interest generated as a result of military requirements has resulted 

 in a large volume of research upon the effects of temperature variations 



