Abstract
Chronic mountain sickness (CMS), found at high altitude, is a term that does not explain the etiopathogenesis of the disease in response to the effect of chronic hypoxia. There is no CMS, but rather pulmonary (mainly), cardiac, carotid, kidney, hematological, or genetic disease. All these are associated with an increase in the hematocrit, or what is now known as polyerythrocythemia. Carlos Monge Medrano originally described CMS more than 90 years ago. He was unable to find an explanation for the signs and symptoms and chose to use the term “loss of adaptation.” This term was originally accepted, but today it can be appreciated as lacking significance and should stop being used.
Undoubtedly, CMS is a chronic hypoxic process resulting in an increase of hemoglobin due to pulmonary lesions (fundamentally) that alter the pulmonary function, thereby reducing the oxyhemoglobin saturation and stimulating the increase of red blood cells. This occurs, essentially, in pulmonary lesions that are sequelae of diverse lung disease giving rise to intrapulmonary shunts or uneven ventilation-perfusion. The term “loss of adaptation” is even semantically inadequate, because in nature, living beings tend to adapt to different environments and circumstances, which could be going to high altitude, temperature changes, solar radiation, ultraviolet radiation, diet changes, and so forth. Consequently, to insist in contemporary medicine on the use of loss of adaptation is not a mistake, but rather, foolishness!
The arterial oxygen content of blood in polyerythrocythemia appears to be increased. However, this apparent increase refers to the maximum oxygen carrying capacity of hemoglobin in blood when fully saturated. That gives rise to two conclusions:1) that the hemoglobin in patients with polyerythrocythemia tends to be normal and is capable of full saturation when exposed to high oxygen pressures; and 2) in the majority of cases, lung disease that results in intrapulmonary shunts and uneven ventilation-perfusion with reduced alveolar pressure of oxygen or cardiac disease with reduced pulmonary perfusion—both result in the most efficient mechanism to compensate for this ventilator or cardiac deficiency, namely, polyerythrocythemia.
The misunderstanding of these concepts has led to the wrong interpretation—such as loss of adaptation—of CMS. Throughout history, all living beings go through evolution to adapt to different environmental conditions. Even aging is an evolution that occurs to finish a vital cycle; it never goes in the reverse way. These concepts of CMS and loss of adaptation are unacceptable.
Again, “The organic systems of human beings and all other species tend to adapt to any environmental change and circumstance within an optimal period of time, and never tend towards regression which would inevitably lead to death.”