0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
JAMA 100 Years Ago |

The Blood Phenomena of Altitude

JAMA. 2013;310(4):435. doi:10.1001/jama.2013.5225.
Text Size: A A A
Published online

Extract

The arrival of the summer months, marking the return of the season of mountain climbing, revives the old problems of the physiology of higher altitudes. We are reminded anew of questions that are of perennial interest, some of which are apparently little nearer their permanent solution than they were a decade or even a generation ago. Foremost among them is the relation of altitude to the circulation, particularly to the number of red blood-cells and their hemoglobin content. In 1882 Paul Bert observed that the blood of animals from La Paz in Mexico, at an altitude of 3,700 meters (12,140 feet), had an oxygen-carrying capacity far in excess of that exhibited by the animals on the lower plains. An explanation of this was forthcoming when, in 1890, Viault found that at the height of 4,392 meters (14,410 feet) in Peru, his blood exhibited from 7 to 8 millions of red corpuscles per cubic millimeter instead of the customary 5 millions. The same facts have since been observed over and over again. But how are they to be interpreted? Are we confronted, in this interesting finding at higher altitudes and their accompanying rarefied atmospheres, with an actual new formation of corpuscles? If so, this is a unique illustration of the adaptive response of the organism to the necessities imposed by the diminished oxygen tension. This interpretation of the blood phenomena of altitude proposed by its earliest investigators has been assailed from time to time by subsequent students of the subject. The objections interposed are themselves of interest because they suggest still other features of the effect of rarefied atmospheres and also modify our views as to the therapeutic possibilities of residence at higher altitudes. Thus it has been maintained that the greater dryness of the air in these environments, together with increased muscular activity, enhances the loss of water from the body through the respiratory tract in particular, and thereby leads to a concentration of the blood. The corpuscular elements will accordingly exhibit an apparent increase in number in a given volume of blood without any real increase in the absolute numbers present in the entire organism. Zuntz and his pupils have emphasized the possibility of an altered distribution of the corpuscles in different vascular areas, leading to a so-called vasomotor displacement of the cellular blood-elements whereby they become more concentrated in those peripheral regions from which specimens for examination are conventionally taken. Abderhalden has analyzed the entire bodies of animals maintained at high altitudes, and failing to find any pronounced increase in hemoglobin, he explains the undoubted augmentation observed in blood-samples by a concentration of the blood through exudation of plasma into the lymph-spaces. It has further been suggested that the red corpuscles may be conserved better at high altitudes and thus a comparative increase result from the failure of normal destruction. Finally, errors in the technic of blood measurements, etc., due to the diminished pressure at altitudes, have repeatedly been propounded.

Topics

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

First Page Preview

View Large
First page PDF preview

Figures

Tables

References

Letters

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Some tools below are only available to our subscribers or users with an online account.

Sign in

Create a free personal account to sign up for alerts, share articles, and more.

Purchase Options

• Buy this article
• Subscribe to the journal

Related Content

Customize your page view by dragging & repositioning the boxes below.

Jobs
brightcove.createExperiences();