The Canadian Medical Association Journal has published at study that shows that completely buried avalanche victims die faster than previously thought. This is a new study lead by Vancouver avalanche researcher Dr. Pascal Haegeli.
Previous burial survival times were researched in Switzerland. It was thought that North American burial survival times were shorter due to a different type of snowpack. This new study shows that they are.
“The rationale was simple; nearly all the Swiss data was based on incidents above treeline while in the US and Canada skiing among trees is more common than not.” – earnyourturns.com
OLD VS. NEW AVALANCHE BURIAL SURVIVAL TIMES:
– Accepted survival phase for burial in avalanche is about 18 minutes based on analysis of 946 Swiss avalanche fatalities from 1980 to 2005 done by Falks & Brugger.
– New Study by Pascal followed 301 avalanche fatalities in Canada found a 10 minute survival phase for burial in an avalanche.
– This cuts accepted survival time almost in half.
– If you’re in a Canadian avalanche, your chances of survial drop to 79% after only 5 minutes; after 15 minutes it drops to only 40%, and after that almost 0%.
– “Overall survivability is about the same for either country; 46.2% in Canada versus 46.9% in Switzerland.” – earnyourturns.com
– Survival rate is lowest in Maritime Snowpack at 41.7%, then comes Continental Snowpack at 43.6%, then Transitional Snowpack at 50.8%. (wet snow is harder to breath thru)
“Our study shows that the more maritime the snow climate, the earlier the onset of asphyxia.” – earnyourturns.com
– In a 2009 study done by Jeff Boyd it was found that 24% of avy victims died from trauma, 76% died from asphyxia (10% had such severe trauma that they’d like have died regardless). Likely about 33% of the non-survivors had major trauma.
CANADIAN STUDY ABSTRACT:
Background: Current recommendations for rescue and resuscitation of people buried in avalanches are based on Swiss avalanche sur- vival data. We analyzed Canadian survival patterns and compared them with those from Switzerland.
Methods: We extracted relevant data for sur- vivors and nonsurvivors of complete ava- lanche burials from Oct. 1, 1980, to Sept. 30, 2005, from Canadian and Swiss databases. We calculated survival curves for Canada with and without trauma-related deaths as well as for different outdoor activities and snow climates. We compared these curves with the Swiss sur- vival curve.
Results: A total of 301 people in the Canadian database and 946 in the Swiss database met the inclusion criteria. The overall proportion of people who survived did not differ signifi- cantly between the two countries (46.2% [139/301] v. 46.9% [444/946]; p = 0.87). Significant differences were observed between the overall survival curves for the two countries (p = 0.001): compared with the Swiss curve, the Canadian curve showed a quicker drop at the early stages of burial and poorer survival asso- ciated with prolonged burial. The probability of survival fell quicker with trauma-related deaths and in denser snow climates. Poorer survival probabilities in the Canadian sample were offset by significantly quicker extrication (median duration of burial 18 minutes v. 35 minutes in the Swiss sample; p < 0.001).
Interpretation: Observed differences in ava- lanche survival curves between the Canadian and Swiss samples were associated with the prevalence of trauma and differences in snow climate. Although avoidance of avalanches remains paramount for survival, the earlier onset of asphyxia, especially in maritime snow climates, emphasizes the importance of prompt extrication, ideally within 10 minutes. Protective devices against trauma and better clinical skills in organized rescue may further improve survival.
READ FULL CANADIAN STUDY HERE: