Altitude


Categories: Uncategorized
Sources: Disturbances Of The Heart

It has long been known that altitude increases the heart rate and

tends to lower the systolic and diastolic blood pressures; that

these conditions, though actively present at first, gradually return

to normal, and that after a prolonged stay at the altitude may

become nearly normal for the individual. Burker [Footnote: Burker,

K.; Jooss, E.; Moll, E., and Neumann, E.: Ztschr. f. Biol., 1913,

lxi, 379. The Influence of Altitude on the Blood, editorial, THE

JOURNAL A. M. A., Nov. 1, 1913, p. 1634.] showed that altitude

increases the red blood cells from 4 to 11.5 percent, and the

hemoglobin from 7 to 10 percent The greatest increase in these

readings is in the first few days. It has also been shown that with

every 100 mm. of fall of atmospheric pressure there is an increased

hemoglobin percentage of 10 percent over that at the sea level.

[Footnote: Blood and Respiration at Moderate Altitudes, editorial,

THE JOURNAL A. M. A., Feb. 20, 1915, p. 670.]



Schneider and Havens [Footnote: Schneider and Havens: Am. Jour.

Physiol., March, 1915.] find that in low altitudes abdominal massage

increases the red corpuscles, and the percentage of hemoglobin in

the peripheral vessels. While there is thus apparently a reserve of

red corpuscles while the individual is in a low altitude, in a high

altitude they find such reserve to be absent; in other words,

abdominal massage did not cause this increase in red corpuscles in

the peripheral vessels. This absence of reserve is easily accounted

for by the fact that after one reaches the high altitude there is an

increase in red corpuscles and hemoblogin in the peripheral blood.



Schneider and Hedblom [Footnote: Schneider and Hedblom: Am. Jour.,

Physiol., November, 1908.] showed that the fall in systolic pressure

at altitudes is greater and more certain than the fall in diastolic,

some individuals even having a rise in diastolic pressure. This rise

in diastolic pressure is probably caused by dyspnea.



Schrumpf, [Footnote: Schrumpf: Deutsch. Arch. f. klin. Med., 1914,

cxiii, 466] on the other hand, finds that normal blood pressure is

not much affected by an ascent of about 6,500 feet, while patients

with arteriosclerosis and hypertension, without kidney disease, have

a fall in pressure. A patient with coronary disease should certainly

not go to any great altitude, while patients with compensated

valvular lesions, he found, were not injured by ordinary heights. He

found that altitude seemed to decrease high systolic and diastolic

pressures, while it even elevated those which were below normal, and

caused these patients to feel better.



Any person who has a circulatory disturbance, and who must or does

go to a higher altitude, should rest for a series of days, until his

blood pressure and blood have reached an equilibrium.



Smith [Footnote: Smith, F. C.: The Effect of Altitude on Blood

Pressure, THE JOURNAL A. M. A., May 29, 1915, p. 1812.] made a

series of observations on blood pressures at Fort Stanton which has

an altitude of 6,230 feet. He took the blood pressure readings in

fifty-four young adults, seventeen of whom were women, and found

that the average systolic reading in the men was 129 mm., and in the

women 121, while the average diastolic in the men was 84, and in the

women 82. Therefore he agrees with Schrumpf that the effect of

altitude on normal blood pressure has been overestimated. In

tuberculosis he found that the effect of altitude was not great. He

does not believe that this amount of altitude, namely, a little more

than 6,000 feet, makes much difference in an ordinary tuberculous

patient. He did not find that artificial pneumothorax made any

important change in the blood pressure. His findings do not quite

agree with Peters and Bullock, [Footnote: Peters, L. S.r and

Bullock, E. S.: Blood Pressure Studies in Tuberculosis at a High

Altitude, Arch. Int. Med., October, 1913, p. 456.] who studied 600

cases of tuberculosis at an altitude of 6,000 feet, and found the

blood pressure was increased, both in normal and in consumptive

individuals. They also found that the increase in blood pressure,

which kept gradually rising up to a certain limit, was indicative

that the tuberculous patient was not much toxic; therefore the

increase in blood pressure was of good prognosis.





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