An international team of experts conducting the first in depth study of major factors in deaths amongst Everest climbers found unexpectedly that things like severe weather deterioration, fatigue and swelling of the brain contributed significantly, dispelling myths about avalanches, falling ice and lung problems being the main factors.

The study was the work of North American and British experts in medicine, physiology and meteorology and is due to be published in the December 20/27 print edition of the British Medical Journal, with an online issue appearing earlier.

Mount Everest is one of the most dangerous places on this planet. Since 1920, thousands of climbers have tried to reach the summit which stands at 8,850 metres (29,000 feet) above sea level, and more than 200 people have died in the attempt.

Dr Kent Moore, Mississauga professor of Physics at the University of Toronto explained:

“Never before has anyone studied these deaths with such a collaborative or fine-tooth approach.”

“We now know with much more certainty what factors play a major role — and which factors do not,” he added.

Moore and colleagues looked into 212 deaths that happened on Everest between 1921 and 1996. They used a number of sources, including the Himalya Database, a compilation of data on expeditions to 300 major peaks in the world’s tallest mountain range.

They found, among other things, that:

  • 192 deaths occurred above base camp (the last camp before roped climbing begins) which represents a 1.3 per cent death rate over the period investigated; much higher than for other tall mountains.
  • Severe weather deterioration was a factor in 25 per cent of all deaths.
  • Above 8,000 metres the people who died without showing lung problems (pulmonary oedema) often showed symptoms of cognitive impairment and cerebral oedema (swelling of the brain).
  • Also common among those who died was a tendency to fall behind other team members, marked fatigue and late summit ascents.
  • Most of the climbers died while descending on the higher slopes, above 8,000 metres, while most of the sherpas (ethnic sherpas from Nepal or Tibet) died on the lower slopes.
  • An Everest expedition typically takes 60 days, but over 80 per cent of the deaths among climbers took place the day they attempted the summit.

Lead author Dr Paul Firth, and instructor in Anesthesia at Massachusetts General Hospital, a teaching hospital of Harvard Medical School in Boston, said:

“It had been assumed that avalanches and falling ice — particularly in the Khumbu Icefall on the Nepal route – were -the leading causes of death and that high-altitude pulmonary edema would be a common problem at such extreme altitude. But our results do not support either assumption.”

Co-author Dr John Semple, Professor of Surgery at the University of Toronto, said that the findings will:

“Provide a foundation of improved safety for both mountaineers and sherpas.”

Firth, who with three co-authors is an and experienced Himalayan mountaineer with expertise in managing high-altitude illness stressed that:

“The majority of those who have died on Everest were in the prime of their lives, with families and friends left bereft.”

Mountaineering is for fun; it’s not worth dying or leaving others there to die. Appropriate caution is the hallmark of the elite mountaineer — the mountain will always be there next year,” he added.

Click here for BMJ.com.

Sources: University of Toronto, Massachusetts General Hospital.

Written by: Catharine Paddock, PhD