News Release

Mountain climbers vulnerable to subclinical lung disorder

Peer-Reviewed Publication

The Lancet_DELETED

N.B. Please note that if you are outside North America the embargo date for Lancet Press material is 0001 hours UK time Friday 25th January 2002.

Three out of four recreational climbers could be at risk of a mild form of the lung disorder called high altitude pulmonary oedema, conclude authors of a study in this week’s issue of THE LANCET.

High altitude pulmonary oedema (HAPE) is characterised by increased pulmonary artery pressure which leads to accumulation of fluid in the lungs. Severe HAPE is rare, occuring in 2-5% of cases, and is thought to only affect people with a specific genetic predisposition. George Cremona from St Raffaele University, Milan, and colleagues from Italy and San Diego, USA, proposed that subclinical HAPE is far more frequent than suspected during even modest climbs of average effort.

262 climbers of Monte Rosa ( a 4559-metre mountain on the Swiss-Italian border) were assessed before ascent and about 24 hours later on the summit 1 hour after arrival. Only one climber was evacuated for HAPE, but 40 (15%) climbers had evidence of lung-function deterioration (chest rales or interstitial oedema [swelling] on radiograph after ascent). Of 37 of these climbers, 34 (92%) showed increased closing volume (the volume of air remaining in the lungs as the narrow airways begin to close after a full expiration; it is increased with oedema and is therefore used as a measure of subclinical HAPE). Of the 197 climbers without clinical evidence of oedema, 146 (74%) had an increase in closing volume –and therefore evidence of subclinical HAPE—at altitude.

George Cremona comments: “If we assume that an increased closing volume at altitude indicates increased pulmonary extravascular fluid, our data suggest that three of every four healthy, recreational climbers have mild subclinical HAPE shortly after a modest climb.”

In an accompanying Commentary (p 276), Larry Sonna from the US Army Research Institute of Environmental Medicine Natick, USA, concludes: “Methods suitable for use on site to better identify individuals at risk of altitude illness, and to identify early those who become ill, are under investigation. Unfortunately, other than a history of recurrent HAPE, there is yet no widely applicable clinical method to tell precisely who will develop clinically significant pulmonary oedema at altitude. In view of the increasing popularity of recreational activities at altitudes capable of producing HAPE, better markers for susceptibility to this disorder are needed.”

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Contact: Dr George Cremona, Unit of Respiratory Medicine, San Raffaele University Scientific Institute, Via Olgettina 60, 20132 Milano, Italy; T) +39 02 2643 7348; F) +39 02 2643 7147; E) george.cremona@hsr.it

Dr Larry Sonna, Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine Natick, MA 01760, USA; E) larry.sonna@na.amedd.army.mil


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