"Loose snow” avalanches account for only a small percentage of deaths and property damage caused by avalanches. “Slab” avalanches are far more lethal. In these, cohesive plates of snow suddenly dislodge and slide down a slope as a unit. These plates may be extremely massive and often travel at devastating velocities. The vast majority of avalanches, about 90 percent, occur on slopes with angles between 30 and 45 degrees, where gravity can catapult them downhill to speeds of 80 mph within about five seconds.

The Himalayas expand their height every second as Indian tectonic plate thrusts 1.77 inches of its vast mass under the Tibetan plate every year. Friction between the two enormous plates causes immense quantities of potential energy to build up. This tension ultimately relieves in the form of sudden jerking movements of vast portions of earth beneath these growing mountains. It is impossible to predict when this will occur, but the resulting rapid motion of the mountains is virtually guaranteed to trigger avalanches.

According to the BBC, 90 percent of people who die in avalanches trigger them themselves with their own alpine activities. Victims usually meet their end from hypoxemia secondary to burial in snow, before hypothermia. Due to the powerful mechanisms involved and the ubiquity of hard objects like rocks and trees in alpine environments, traumatic injuries also commonly contribute to causes of death, and certainly to morbidity in survivors. National Geographic cites global avalanche mortality at about 150 deaths per year. Statistics indicate that 93 percent of avalanche victims survive if dug out within 15 minutes. After this critical time period survival rates drop down. After 45 minutes of burial in snow after an avalanche, only 20 to 30 percent of victims remain alive. After two hours, survival is rare. 

A study of 204 avalanche fatalities in Canada between 1984 and 2005 found that asphyxia was responsible for 75 percent of deaths overall, while trauma was the primary cause of 24 percent. The remaining one percent died of hypothermia. When data was isolated for the subset of victims who were mountain climbers, however, trauma was the primary cause of death in 42 percent of avalanche fatalities. Asphyxiation is the most common direct cause of avalanche deaths. Minimizing rescue times of avalanche casualties is of the utmost importance to optimizing survival. If a victim can be rescued within 18 minutes, the survival rate is greater than 91 percent, according to a study in the Canadian Medical Association Journal. The survival rate drops to 34 percent in burials lasting between 19 and 35 minutes. Thus, every second saved in the victim location and evacuation is vital to their survival.

Therefore, busy ski areas in many developed countries are served by a dense network of emergency medical helicopters, allowing an immediate HEMS response to avalanche accidents whenever they strike. Staff are highly trained and extensively experienced in medical avalanche rescue, as this service performs about 80 avalanche rescue missions each winter. 

Nepal is in desperate need of service of this caliber for the hundreds of thousands of trekkers and mountaineers who visit potentially high-risk areas of the Himalayas every year, as well as the many vulnerable Nepali communities in these areas.  Many preventable deaths occur every year in the Nepali mountains. Conditions such as High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE) are easily preventable and treatable.  All we need is timely recognition of the condition and minimal resources in the right place at the right time.  The development of high-quality emergency medical services (EMS) and HEMS in Nepal’s mountains should be made a national priority. Many preventable deaths could be avoided with such services, and sadly many more will occur until this crucial goal is realized. 

Although private Nepalese airline companies provide helicopter rescue services in these areas, most of these vehicles are unarmed with any medical personnel or equipment, which makes the effort unproductive to its potential. A dispatcher system is of the utmost importance, with a team of helicopters as well as medical personnel and rescue teams.  All of these are present in the country but a lack of integration of these has been the primary reason for high mortality in this region.  Nepal does not have any helicopter ambulance; patients are carried to the hospitals by commercial helicopters.  Grande International Hospital, a hospital based in the capital Kathmandu, has taken the lead in carrying live saving equipment, and providing drugs to doctors and nurses while on rescue missions.

On April 25 2015, a powerful earthquake of 7.8Mw hit the heart of Nepal.  This, together with strong aftershocks, resulted in about 10,000 deaths, with more than 23,000 injured and about 2 million displaced people. Mount Everest was approximately 220 kilometers (140 mi) east of the epicenter, and between 700 and 1,000 people were on or near the mountain when the earthquake struck, including 359 climbers at Base Camp.  The earthquake triggered several large avalanches on and around the mountain. One avalanche, originating on the nearby peak of Pumori, swept into South Base Camp and then through part of the Khumbu Icefall.  The local EMS system was found wanting, which may be understandable as it is only in its infancy in Nepal. Had it not been for the swift response from the international community, these numbers would have looked far worse.

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These natural disasters are unavoidable but the loss of lives in such calamities is not.  If we simply ask ourselves why hundreds of lives are lost in the Himalayas, we will find the answer glaring at us. It is undeniably due to poor management, a poor communication system, and lack of information.  The need of proper HEMS is finally being realized and should be a top priority for all the medical clinic and NGOs working in these mountains.  The country has numerous hurdles to the improvement of EMS in mountains due to lack proper road services; HEMS seems to be the only solution, which is vital to overcome natural disasters in future. 

There exists a number of obstacles, including financial, political, cultural, and institutional.  Financial limitations make the change difficult as resources are needed to fund the establishment HEMS focused faculty.  Locally and culturally sensitive education must be developed to sustainably improve HEMS in Nepal.  Efficient management with limited resources through improved triage, management protocols, and team management of patients could significantly improve care in the mountains.  When trekking or mountaineering in Himalayans, regardless of experience or skill level, prepare oneself with knowledge of avalanches and take the appropriate precautions and safety measures. The development and starting of a training program in Emergency Medicine Services is a step for the advancement of HEMS in Nepal. We believe, in future natural disasters, these providers will show immediate effective response in terms of rescue, treatment, and shelter, which was beyond the capacity of the locals alone in this recent earthquake.