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Avalanche Victim Physiology and Medical Treatment After Rescue
Colin K. Grissom, M.D.
Critical Care Medicine, LDS Hospital
Associate Medical Director, Life Flight, Intermountain Health Care
Assistant Professor of Medicine, University of Utah
Learning Objectives:
At the completion of the lecture on "New Hope for Surviving the Avalanche",
participants will be able to:
1.
Understand the respiratory physiology of asphyxiation during avalanche burial.
2.
Know the importance of companion rescue as the major determinant of survival
during avalanche burial.
3.
Identify the priorities of medical care for an avalanche burial victim.
4.
Discuss the rate of development of hypothermia during avalanche burial and the
contribution of core temperature afterdrop in extricated avalanche burial victims.
Summary
Asphyxiation is the major cause of death during avalanche burial and is time
dependent. Avalanche burial victims extricated within 15 minutes have a greater than
90% chance of survival, but this decreases to about a 30% chance of survival if extricated
after 30 minutes, emphasizing the need for companion rescue using avalanche
transceivers and shovels. Survival beyond 30 minutes of burial is dependent on an air
pocket for breathing. The larger the size of the air pocket, the longer survival is possible
during avalanche burial. This is because asphyxiation during avalanche burial is caused
by rebreathing expired air that contains 16% O2 and 5% CO2. A larger air pocket
provides more surface area for diffusion of expired air away from an avalanche burial
victim, allowing more ambient air from the snowpack to diffuse into the air pocket for
inspiration. Opening the airway and assuring adequate ventilation and providing
supplemental oxygen are the primary medical interventions in an extricated avalanche
burial victim. If they avalanche victim is conscious then mild hypothermia is most likely
and treatment consists of proving warm dry insulation and warm sugar containing liquids.
Rewarming will occur through shivering. The avalanche burial victim who is not
shivering because they have progressed to moderate or severe hypothermia will require
medical transport to a hospital for definitive rewarming. Unconscious avalanche burial
victims who are breathing may require intubation for airway control and assisted
ventilation, and are likely moderately to severely hypothermic. Avalanche burial victims
extricated in asystolic cardiac arrest have most likely died from asphyxiation, but if burial
time is greater than one or two hours and core body temperature is less than 30 ° C they
may be severely hypothermic and resuscitation efforts may be continued while the patient
is transported to a medical facility capable of extracorporeal rewarming.