Induced Hypothermia to 4.2°C with Neurologically Intact Survival: A Forgotten Case Series

The lowest recorded core temperature from which a person with accidental hypothermia has survived neurologically intact is 11.8°C in a 2-y-old boy. The lowest recorded temperature from which an adult has been resuscitated neurologically intact is 13.7°C in a 29-y-old woman. The lowest core temperature with survival from induced hypothermia has been quoted as 9°C. We discovered a case series (n=50) from 1961 in which 5 patients with core temperatures below 11.8°C survived neurologically intact. The lowest core temperature in this group was 4.2°C. The authors also presented cardiovascular and other physiologic data at various core temperatures. The patients in the case series showed a wide variation in individual physiological responses to hypothermia. It is not known whether survival from accidental hypothermia is possible with a core temperature below 11.8°C, but this case series suggests that the lower limit for successful resuscitation may be far lower. We advise against using core temperature alone to decide whether a hypothermic patient in cardiac arrest has a chance of survival.