Study of Nepalese pilgrims challenges diagnosis of acute mountain sickness

January 09, 2014

A study led by University of British Columbia scientists calls into question a widely used method of diagnosing acute mountain sickness.

The Lake Louise Score Questionnaire has been used for more than two decades to determine if someone was suffering from acute mountain sickness (AMS), which strikes people at elevations above 2,500 metres. The lack of oxygen causes a spectrum of ailments, from headaches to vomiting to potentially fatal swelling of the brain or lungs.

The questionnaire, valued for its simplicity under austere conditions, asks people who are feeling ill at altitude to rate themselves in five areas - headache, nausea, weakness, dizziness and sleep quality.

A team co-directed by Dr. Michael Koehle, an associate professor in UBC's Faculty of Medicine and the School of Kinesiology, used the questionnaire on nearly 500 Nepalis who hiked to a 4,380-metre-high lake for a religious festival. Nearly a third of them were diagnosed with AMS.

A statistical analysis of the results, published recently in the journal High Altitude Medicine & Biology, found that the sleep score did not coincide with the answers on the other four parts of the questionnaire. If sleep quality was removed from the questionnaire, the reliability of the overall score increased.

Including the sleep score in the questionnaire, Koehle says, could lead to some people being treated unnecessarily, and others not getting treatment they need - which usually consists of going down to lower elevations.

"Although people with AMS frequently do have trouble sleeping, that symptom can be affected by many other factors, including noise, comfort and the mild dehydration that often occurs at high altitude," Koehle says. "And while the entire questionnaire is based on a self-assessment, rating the quality of your own sleep is particularly subjective. So I would recommend removing that from the questionnaire."
-end-
BACKGROUND | DIAGNOSING ACUTE MOUNTAIN SICKNESS

Competing questionnaires: The Lake Louise Score Questionnaire was created at an annual conference on hypoxia (low oxygen levels) held in Lake Louise, Alberta. Another tool for diagnosing AMS, called the Environmental Symptom Questionnaire III (ESQ III), covers 65 measurements or symptoms, but calculating that score is difficult without a computer. The ESQ III does not consider sleep quality.

A simple sum: The Lake Louise Score Questionnaire asks people to rate themselves on five criteria on a scale of zero to three, with zero meaning "normal" or "good," and three meaning "severe" (or, in the case of sleeping, "could not sleep at all"). A person must have a score of one or higher on the headache question, and an overall score of three or higher to be diagnosed with AMS.

A simple cure: People with severe AMS can be given extra oxygen if it's available. But the most reliable and easiest treatment is descending to lower elevations.

An annual pilgrimage: The study was conducted during a pilgrimage undertaken by as many as 20,000 Nepalis, most of whom live at 1,400 metres. Over a day or two, they walk to 4,380 metres, many of them clad only in saris and flip-flops.

Mountain medicine expert: Koehle sees patients at UBC's Allan McGavin Sports Medicine Centre, and in addition to the usual gamut of ailments and injuries - muscle and joint aches, breathing problems, concussions and fatigue - he has developed a specialty in helping people who spend time at high elevation for trekking, mining exploration (mostly in the Andes of South America), or training for athletic competition.

University of British Columbia

Related Sleep Articles from Brightsurf:

Size and sleep: New research reveals why little things sleep longer
Using data from humans and other mammals, a team of scientists including researchers from the Santa Fe Institute has developed one of the first quantitative models that explains why sleep times across species and during development decrease as brains get bigger.

Wind turbine noise affects dream sleep and perceived sleep restoration
Wind turbine noise (WTN) influences people's perception of the restorative effects of sleep, and also has a small but significant effect on dream sleep, otherwise known as REM (rapid eye movement) sleep, a study at the University of Gothenburg, Sweden, shows.

To sleep deeply: The brainstem neurons that regulate non-REM sleep
University of Tsukuba researchers identified neurons that promote non-REM sleep in the brainstem in mice.

Chronic opioid therapy can disrupt sleep, increase risk of sleep disorders
Patients and medical providers should be aware that chronic opioid use can interfere with sleep by reducing sleep efficiency and increasing the risk of sleep-disordered breathing, according to a position statement from the American Academy of Sleep Medicine.

'Short sleep' gene prevents memory deficits associated with sleep deprivation
The UCSF scientists who identified the two known human genes that promote 'natural short sleep' -- nightly sleep that lasts just four to six hours but leaves people feeling well-rested -- have now discovered a third, and it's also the first gene that's ever been shown to prevent the memory deficits that normally accompany sleep deprivation.

Short sleep duration and sleep variability blunt weight loss
High sleep variability and short sleep duration are associated with difficulties in losing weight and body fat.

Nurses have an increased risk of sleep disorders and sleep deprivation
According to preliminary results of a new study, there is a high prevalence of insufficient sleep and symptoms of common sleep disorders among medical center nurses.

Common sleep myths compromise good sleep and health
People often say they can get by on five or fewer hours of sleep, that snoring is harmless, and that having a drink helps you to fall asleep.

Sleep tight! Researchers identify the beneficial role of sleep
Why do animals sleep? Why do humans 'waste' a third of their lives sleeping?

Does extra sleep on the weekends repay your sleep debt? No, researchers say
Insufficient sleep and untreated sleep disorders put people at increased risk for metabolic problems, including obesity and diabetes.

Read More: Sleep News and Sleep Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.