For the past four decades, Chinese military doctor Zhang Xizhou has been fighting to keep soldiers safe from altitude sickness while guarding the borders between China and Tajikistan and India.

Those soldiers work 4,500 meters above sea level at decreased oxygen levels.

Serving with the No. 18 Hospital of the Xinjiang Military Command, Zhang said he is comforted by the fact that soldiers are no longer dying from altitude sickness.

"We managed to reduce the mortality rate from 1.7 percent to zero percent over the past 30 years," he said.

The 60-year-old doctor is now a renowned researcher at the Mountain Sickness Research Institute within the hospital. It serves dozens of military companies working along China's western most border where the Pamir, Karakoran and Himalayan mountain ranges intersect.

Every 1,000 meters up equals 10 percent less oxygen in the air. In a number of border posts in that region, thousands of soldiers live at least one year on oxygen which is 45 percent less than normal.

To them, high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE), extreme forms of altitude sickness, are major threats.

According to military authorities, more than 300 soldiers have died of high altitude sickness since 1949.

"In the past 15 years, no one died of HAPE and HACE," Zhang said.

Since its founding in 1987, the Mountain Sickness Research Institute has made great progress towards keeping soldiers healthy.

In the early 1990s, Zhang and his colleagues developed a pill, taken daily, which reduces the incidence of acute altitude sickness among soldiers from 90 to 40 percent.

During the same period, they also conducted the first brain surgery at a medical camp with an altitude of 4,300 meters. Zhang is also given partial credit for saving the first-ever patient from acute myocardial infarction at an altitude of 5,200 meters.

Currently, every Chinese border company has a doctor, basic medicine and equipment. Medical teams visit soldiers annually for regular exams. They also promote altitude sickness prevention.

Every border company stationed at altitudes higher than 3,000 meters is equipped with oxygen machines. Soldiers there are required to breath in oxygen for an hour each day.

"Oxygen therapy has the notable effect of improving their physical and psychological health," Zhang said.

A zero percent mortality rate for altitude sickness isn't only attributed to medical progress.

"A basic change of mind set is another important reason," he said. "Years before, soldiers would consider themselves brave and honorable if they did not ask for leave due to a light cold. Now, they have a rational understanding about their responsibilities. They know good health is vital to their duty."

The Sanshiliyingfang medical center, deep in the Karakoran Mountains in Tibet, is in charge of medical care for more than ten border posts located higher than 4,500 meters in altitude.

"The number of hospitalized patients is reducing year-by-year. In the first half of this year, only 40 soldiers were sent here. That's half of the figure from the same period last year," said Wang Chengxu, the medical center's director.

More and more soldiers and officers come for advice on how to improve their health, he said.

"My colleagues and I are very happy about doing this simple work. To prevent high altitude sickness is much more important than treatment."

(Xinhua News Agency December 24, 2008)