Posted by Forrest Brownell on August 14, 1997 at 01:25:28:
In Reply to: Not Nonsense at All (WAS 'Re: Cold Comfort...') posted by Forrest Brownell on August 13, 1997 at 21:43:48:
The geese having flown on, I'll return to my interrupted commentary:
Phil Winterbourne does err in one instance. High altitude pulmonary oedema
(HAPE), which Mr Winterbourne correctly associates with climbing, should not be
confused with high altitude cerebral oedema (HACE). The two conditions each
arise in response to too-rapid ascent to high elevation -- going too high, too
fast -- but, though they may well both be manifestations of a common
pathological process, they are more-or-less distinct clinical entities. HAPE
presents as dyspnea and cough progressing to severe respiratory distress, coma
and death; HACE, as headache and unsteadiness, followed by progressive mental
dysfunction, confusion, and ultimately unconsciousness and death. If a climber
suspects either condition, of course, he (or she) should descend immediately to
a lower altitude.
The etiology of these related conditions is complex; it is, I believe, still the
subject of active research and investigation. The clinical signs, however, owe
more to the accumulation of fluid from capillary seepage in the lungs and brain
stem than to clotting, -- though here, too, Mr Winterbourne correctly identifies
thrombosis as another hazard associated with altitude.
Anyone planning to climb above 8,000 ft (2,400 m) must therefore be thoroughly
familiar with HAPE and HACE, as well as the more common, related conditions
known as Acute Mountain Sickness (AMS) and High Altitude Retinal Haemorrhage
(HARE). I won't attempt a summary of the literature here. As a start, the
interested reader is referred to Chapter 21 ('Medical Problems of High
Altitude') of James A. Wilkerson's Medicine for Mountaineering, 4th edition
(1992).
Come to think of it, there's a lot to be said for sailing.
Forrest