Imagine this: you are backcountry skiing on your vacation in Switzerland and your partner is about to take the first run down a beautiful line of fresh powder. As you watch him turn gracefully through the snow, the ground beneath him begins to crack. He has triggered an avalanche and thousands of pounds of snow release around him and go careening towards the base of the mountain. Three minutes later, your friend is buried. Luckily, you were prepared and you both had an avalanche beacon, shovel, and a probe. After 25 minutes you manage to find your friend and uncover his face and chest, but he is pulseless and not breathing. How do you manage this patient?
Avalanche rescue is a battle against time and most successful rescues are performed by the victim’s partner or other bystanders. This is because asphyxia is by far the most common cause of death in avalanche victims, usually occurring within 10-20 minutes of burial. Trauma contributes a to a portion of deaths as well (which varies depending on the terrain) and hypothermia accounts for a very small number of deaths. In North America, emergency services or ski patrol often cannot arrive on scene fast enough to do anything more than a body recovery. If you engage in activities in avalanche terrain, you should be prepared for both rescue and medical management of potential victims. The International Commission for Alpine Rescue (ICAR) provides some excellent guidelines about avalanche resuscitation, which were updated in 2015. We will review those here.
The first step is to uncover the victim’s head and chest. We will not detail that process in this post, but you should be proficient and practice before entering avalanche terrain. If the victim is obviously dead or if resuscitation would endanger rescuers, then do not continue. If the victim has been buried for less than 60 minutes, begin standard resuscitation as needed. If the burial time is unknown, then core temperature (>30°C) can be used as a substitute. With a burial time greater than 60 minutes (or T< 30°C) and signs of life, continue resuscitation as per normal and transfer to the closest hospital with extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass (CPB) to facilitate rewarming.
This is where it gets a little more complicated. If there are no signs of life after 60 min of burial (or T< 30°C), it is recommended that you obtain an ECG. The ICAR algorithm was created in Europe where the backcountry access is exceptionally fast, there is often a physician involved in the rescue, and teams usually have ECGs available. If this is available, any organized rhythm (VF, VT, PEA) warrants resuscitation, as these are prognostically favourable rhythms. ECGs are likely not available in most North American prehospital avalanche situations. If not, then consider the airway (which you hopefully already assessed). If the airway is obstructed, then do not continue because that patient died of asphyxia early. If the airway is patent or it is unknown, then resuscitate. Potassium may be used as a prognostic indicator but again, it is likely not available in most situations. Any time you are resuscitating a patient who has been buried longer than 60 minutes, is hypothermic, or has cardiovascular instability, they should be transferred to a hospital with the highest possible level of care and either ECMO or CPB capabilities.
Figure 1: ICAR 2015 Avalanche Resuscitation Guidelines. Image from Mountain Rescue Association.
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Alana Hawley, M.D.
Wilderness Medicine Fellowship, University of Utah
PGY-5 Emergency Medicine, McMaster University
Article photo credit:
Lukas Neasi via Unsplash