MOUNTAIN SICKNESS OF AVIATORS.

Oamaru Mail, Volume XXXIX, Issue 10671, 21 January 1911, Page 3 (Supplement)

MOUNTAIN SICKNESS OF AVIATORS.

Mountain-climbers tell us that at groat altitudes disagreeable physiological symptoms manifest themselves. Some a-JS-Tt that those can be detected at heights o: a few thousand feet, and mai'iy say that they are unable to live in cities like Denver, Col., which its citizens are fond of reminding us is 'M mil'- high." What would "he the result if. instead of attaining these altitudes ironl soa-leviil. by the slow process of (limbing, we could be transported from one level to the "other in a few minutes:-' This is precisely what happens iu a lofty aeroplane flight, where the ascent takes but a short time and the descent is made in four or five minutes from an elevation of perhaps SO(K) feet. We -know that quick "transition from high to low pressure in the caisson of a subaqueous tunnel may have, fatal results. Something of the sime sort occurs in aviation, and may account for some of the mysterious accidents, we'are told by a writer in' The Lancet. This new problem of the physiological effects upon the aviator seems to have attracted little notice, he remarks." Wcrread: "The rapid ascent to great altitudes exposes the body to conditions different from any terrestrial ones.- Mountain climbing offers some analogy, but it differs in the fact that the transition from the high atmospheric pressure, of tlie sea-level to a .low. pressure takes place much more slowly. In the Gazette Hebdomadaire des Sciences Mcdicales do Bordeaux of- September 25 Prof. R. Moulinier has reported soma interesting observations on the bloodpressure of aviators who have ascended to high altitudes." On alighting after ascending to a height of four or five thousand feet,. the aviator's hands and feet are blue, his eves are bloodshot, and his pulse is high- He has headache aud ringing in the oars. Sometimes there" is a tendency to sleep, and this may be felt eveii during flight. After the flight the blood-pressure is always increased, sometimes by 30 to, 40 per cent. To quote further: •*_ ; ■; "This increase in'pressure is all tlie; more remarkable as.vthe.- aviators were athletes in full training.;- The rise was less: marked in aviators who were fatigued. These palpitation of the heart and marked acceleration of the pulse (108). In one case [symptoms] . of functional insufficiency or the heart, and vertiginous movements, were observed in an aviator who, after a flight of an hour,, had reached height of 1000 meters [3200 feet]; No rise in blood-pressure was found in. aviators who flew at low altitudes, such as 100 to 150 meters. As to the cause of the rise in blood-pressure, Professor Moulinier puts forward the hypothesis that it is due to the sudden descent to earth in four or five minutes from a hehdit of 1000 to 2000 meters which was'attained in 20 to 25 minutes. • - In the short time of the descent the c"rcnlptorv system had not time to beconi" adapted to the change of pressure. He therefore advises aviators to descend more slowly. He also points out the dangerous- fatigue to which flight at high altitudes exposes the circulatory apparatus by provoking increased and irregular activity of the heart and vessels. A sound heart and -uno'.e arteries are absolutely necessary to an aviator. The list of disfatalities to aviators has become "comparatively long in a very short time. The accidents arc always attributed to some mechanical cause some breakdown in the machine or unexpected current of air.. No doubt this is usually true, but it seems to us quite oossible that in some cases the breakdown mav have been m the human machine, 'which is exposed to a new and peculiar stress, both -physical and psvchicid It is curious that this point does not seem to have received attention."