Publication

Avalanche survival depends on the time of day of the accident: A retrospective observational study

Journal Paper/Review - Mar 24, 2022

Units
PubMed
Doi

Citation
Rauch S, Zweifel B, Brugger H, Albrecht R, Pasquier M, Strapazzon G, Meuli L, Josi D, Koppenberg J, Pietsch U. Avalanche survival depends on the time of day of the accident: A retrospective observational study. Resuscitation 2022
Type
Journal Paper/Review (English)
Journal
Resuscitation 2022
Publication Date
Mar 24, 2022
Issn Electronic
1873-1570
Brief description/objective

INTRODUCTION
We aimed to investigate the relationship between the time of the day and the probability of survival of completely buried avalanche victims. We explored the frequency of avalanche burials occurring after sunset, and described victims' characteristics, duration of burial and rescue circumstances compared to daytime avalanches.

METHODS
In this retrospective, observational study, we analysed avalanche data from the registry of the Swiss Institute for Snow and Avalanche Research, from 1998 to 2020.

RESULTS
A total of 3,892 avalanche victims were included in the analysis, with 72 of the accidents (1.85%) occurring in the nighttime. Nearly 50% of the victims involved in nighttime avalanche accidents were completely buried, compared to about 25% of victims in daytime avalanches. Completely buried victims were rescued by a companion less often at night than in the daytime (15% vs. 51%, p<.001). The search and rescue of completely buried avalanche victims took longer during the nighttime compared to the daytime (median 89 min vs 20 min, p=.002). The probability of survival decreased as the day progressed; it was highest at around midday (63.0%), but decreased at sunset (40.4%) and was the lowest at midnight (28.7%).

CONCLUSIONS
Avalanche accidents at night are a rare event, and probability of survival after complete burial is lower during the nighttime compared to the daytime. The most relevant reason for this is the longer duration of burial, which is explained in part by the lower rate of companion rescue and the lower rate of victim localisation with an avalanche transceiver.