By Joshua Calhoun

May 24, 2002 Mountaineers may be breathing easier this year, literally. According to a study published this week in the New England Journal of Medicine, prophylactic inhalation of salmeterol, a drug commonly used for asthma treatment, significantly reduces the risk of high-altitude pulmonary edema (HAPE).

The study, conducted by a team of twelve Swiss doctors, tested the preventative value of salmeterol at high altitudes on climbers with known susceptibility to HAPE. Out of a test group of 37 subjects, 14 of the 19 given a placebo inhalant showed clinical signs of HAPE, compared to only six out of the 18 given salmeterol.

"It's a remarkable study," says Dr. Peter Hackett, President of the International Society of Mountain Medicine and one of the foremost experts in the field of high-altitude medicine. "There are three criteria I use for judging a research study: is it new, is it true, and is it important. I give this study an 'A' in all of those areas."

HAPE is a severe type of altitude sickness that causes fluid to pool in the lungs. While it's normal in everyday life for some fluid to collect in the lungs, the fluid is typically absorbed into the lymphatic system. HAPE, which is influenced by a climber's rate of ascent and amount of exertion, results when there is so much fluid in the lungs that the lymphatic system can't absorb it quickly enough. Fluid builds up, and the person literally begins to drown.

Only one medication now available, nifedipine, has been proven to prevent HAPE, and rapid descent is the only sure-fire way to combat it once symptoms — extreme fatigue, breathlessness at rest, fast, shallow breathing, gurgling or rattling breaths, blue/gray lips or fingernails, and drowsiness — appear. But nifedipine is an oral medication that enters the body through the circulatory system and can cause severe side effects like decreased blood pressure, headaches, and ankle swelling, all potential hindrances for climbers at high altitudes.

In contrast, salmeterol, an inhalant, immediately enters the lungs and stays there, so the body gets medication right where it's needed most.

According to Hackett, salmeterol, the chemical name of the common inhaler brand Serevent, is a cousin to the faster and shorter-acting Ventolin, a drug well known to asthma sufferers and one he's used to treat HAPE in the past.

"One time I was at a high camp on [22,493-foot] Ama Dablam and I thought I was coming down with HAPE and the only medicine I had at the time was a Ventolin inhaler," he recalls. "I wasn't able to get down because of a huge windstorm. It's hard to know for sure but it may have made a difference in my survival."

This past January, another study published in the medical journal Lancet suggested that HAPE is much more prevalent among climbers that previously thought. Researchers reported that a surprising 60 percent of climbers at the summit of Monte Rosa—a moderate, non-technical 14, 957-foot peak in the Alps—had signs of subclinical HAPE and 15 percent had clinical HAPE. Prior to the study, HAPE was believed to affect only two to four percent of climbers above 8,000 feet.

Dr. Urs Scherrer, Professor of Internal Medicine at Centre Hospitalier Universitaire Vaudois in Switzerland and a member of the team that studied salmeterol, says those numbers shouldn't be used to justify dolling out the drug to everyone, especially since there's no reliable test that predicts whether someone is particularly susceptible to HAPE. "For now, its use should be restricted to people who have suffered from documented HAPE before," he says. "I think the rule should be if you do mountain climbing, you should be able to do it without drugs. It is only the people with real problems who should take this medication."

But such admonitions may have little effect on the actions of climbers, according to Hackett.

"A lot of climbers are popping dex (dexamethasone) on summit day just to protect their brains and I wouldn't be surprised if people begin taking a squirt of salmeterol for their lungs before summitting, just in case."