After 15 minutes under an avalanche, your chance of survival decreases rapidly

While the death rate for partially buried avalanche victims is around four percent, it is significantly higher for completely buried avalanche victims at 52.4. According to experts, the chance of survival decreases discontinuously the longer the burial lasts.

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After 15 to 20 minutes under an avalanche, there is a steep drop in the survival curve, according to the Eurac Institute for Alpine Emergency Medicine in Bolzano. In the first phase it is still at 91 percent (nine percent die from mechanical injuries during this time), then a “fatal kink” occurs and the curve drops rapidly to around 30 percent. In this phase, all victims with obstructed airways die of rapid suffocation. The basic requirement for survival in this phase is a clear airway. The presence of a respiratory cavity is an additional plus, experts know.

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Snow density plays an important role

The most recent analyzes have shown that snow density also plays a role. In a continental climate like in the Alps, the survival curve does not fall off as quickly as, for example, near the Pacific. A Canadian study has shown this. The experience gained in the Alps also shows that the chances of survival in spring with wet snow decrease quickly after just ten to 15 minutes. Another phenomenon is that the number of fatally injured people has increased. But this is because winter sports enthusiasts are increasingly traveling on steep and rocky terrain.

What is also new is that new rescue and treatment guidelines are recommended if the person is buried for longer than 60 minutes, with a clear airway and a core body temperature of less than 30 degrees: the avalanche victim should not be rescued as quickly as possible, but rather as carefully as possible. Treating hypothermia is then a priority. Victims with a core body temperature – this is measured in the esophagus or middle ear – below 30 degrees would have a better chance of survival in the event of a cardiac arrest and subsequent resuscitation than those who were not hypothermic. The body’s need for oxygen decreases with the cold.

“Many victims rescued from impassable terrain”

If an avalanche victim first cools down and then suffers a cardiac arrest, the prognosis is significantly better. Provided that the injured person undergoes continuous resuscitation and is then warmed up in a clinic using a heart-lung machine.

It has also been shown that the resuscitation of severely hypothermic avalanche victims, i.e. with a core body temperature of 28 to 20 degrees, can be temporarily interrupted for transport. For example, it would be possible to resuscitate for five minutes and then take a five-minute break for transport, said Brugger: “Many avalanche victims are rescued from exposed and impassable terrain.”