Colin Grissom, M.D. "New Hope For Surviving the Avalanche"
Page
11
differentiate core temperature cooling rate during snow burial as compared to during
medical transport. Grissom and colleagues report that core body temperature cooling rate
increases transiently after extrication from snow burial. Core body temperature cooling
rate accelerated by 50% for 25 minutes after extrication in subjects buried in snow for 60
minutes
12
. An accelerated cooling rate during and after extrication places avalanche
burial victims at greater risk of complications due to hypothermia. Every effort should be
made by rescue personnel to prevent further heat loss in avalanche burial victims starting
as soon as possible during extrication from the snow.
Core temperature cooling rate during avalanche burial may also be estimated from
anecdotal reports of prolonged survival during avalanche burial. In one case a 25 year old
male snowboarder with a large air pocket in front of his body survived 20 hours of
avalanche burial
22
. At the time of extrication he had a core body temperature of 25.6
° C
(tympanic) in 5
° C temperature snow and was spontaneously breathing with a Glasgow
Coma Score of 8, heart rate 35, and a palpable pulse. Core body temperature cooling rate
in this anecdotal report was about 0.6
° C/hr. The large air pocket likely allowed adequate
diffusion of expired air away from inspired air and prevented asphyxiation. In that same
rescue the survivor's companion was found dead from asphyxiation after 20 hours of
burial with a core body temperature of 6
° C (tympanic) which is an average core body
temperature cooling rate of about 1.5
° C/hr. Another case of survival from prolonged
burial occurred in a 21 year old female snowshoe hiker
16
. She survived 24 hours of
avalanche burial with a large air pocket around her head, and was extricated unconscious.
After transport to a local ski lodge where she was placed in warm insulation and warmed
intravenous fluids were infused, she regained consciousness and had a core body
temperature of 29.3 ° C. These anecdotal reports demonstrate that core body temperature
cooling rate during avalanche burial may vary significantly depending on adequacy of
ventilation as determined by the size of an air pocket.
Table 3. Hypothermia Clinical Pre-Hospital Evaluation: Swiss Society of Mountain
Medicine Definitions
4
Hypothermia I: patient alert, shivering (core temperature about 35 32 ° C)
Hypothermia II: patient drowsy, non-shivering (core temperature about 32 28 ° C)
Hypothermia III: patient unconscious (core temperature about 28 24 ° C)
Hypothermia IV: patient not breathing (core temperature < 24 ° C)
