Institute of Mountain Emergency Medicine, Eurac Research, Via Ipazia 2, Bolzano, Italy; Medical University Innsbruck, Innerkoflerstrasse 1, 6020 Innsbruck, Austria. Electronic address: firstname.lastname@example.org.
Department of Emergency Medicine, University of Colorado, Anschutz Medical Campus, Mail Stop B-215, 12401 17th Avenue, Aurora, CO, 80045, USA; International Commission for Mountain Emergency Medicine (ICAR MedCom), Zürich, Switzerland. Electronic address: email@example.com.
Clinical staging of accidental hypothermia is used to guide out-of-hospital treatment and transport decisions. Most clinical systems utilize core temperature, by measurement or estimation, to stage hypothermia, despite the challenge of obtaining accurate field measurements. Recent studies have demonstrated that field estimation of core temperature is imprecise. We propose a revision of the original Swiss Staging system. The revised system uses the risk of cardiac arrest, instead of core temperature, to determine the staging level. Our revised system simplifies assessment by using the level of responsiveness, based on the AVPU scale, and by removing shivering as a stage-defining sign.
International Commission for Mountain Emergency Medicine (ICAR MedCom), Zürich, Switzerland; Institute of Forensic Medicine, University of Bern, Bern, Switzerland. Electronic address: firstname.lastname@example.org.
Determination of death requires specific knowledge, training, and experience in most cases. It can be particularly difficult when external conditions, such as objective hazards in mountains, prevent close physical examination of an apparently lifeless person, or when examination cannot be accomplished by an authorized person. Guidelines exist, but proper use can be difficult. In addition to the absence of vital signs, definitive signs of death must be present. Recognition of definitive signs of death can be problematic due to the variability in time course and the possibility of mimics. Only clear criteria such as decapitation or detruncation should be used to determine death from a distance or by laypersons who are not medically trained. To present criteria that allow for accurate determination of death in mountain rescue situations, the International Commission for Mountain Emergency Medicine convened a panel of mountain rescue doctors and a forensic pathologist. These recommendations are based on a nonsystematic review of the literature including articles on determination of death and related topics.
Department of Emergency Medicine, Alaska Native Medical Center, Anchorage, AK; Department of Emergency Medicine, Stanford University Medical Center, Stanford, CA; International Commission for Mountain Emergency Medicine (ICAR MEDCOM), Zürich, Switzerland.
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.