Скачать или смотреть Can COPD patients go to plateau? Why people with 75% SPO2 can be alive and kicking?

In the higher the altitude areas, the pressure is lower, and the air in thinner with the less oxygen.
For example, in low altitude areas, 100g total hemoglobin can produce 90g of oxygenated hemoglobin to meet human needs. At this point, oxygen saturation is 90%, but in high altitude areas, oxygen is less, and 100g of total hemoglobin can only produce 40g of oxygenated hemoglobin.
At this point, in order to inhale enough oxygen to meet the demand, the body will experience a compensatory reaction, increasing the oxygenated hemoglobin to 90%.
According to short-term exposure and long-term altitude exposure, compensatory response can be divided into two stages:
The first stage is to increase ventilation and avoid a decrease in PAO2 as much as possible, so that oxygenated hemoglobin reaches 90g and oxygen saturation reaches 90%. This is the reason why feel tight breathe when people just climbed the plateau
The second stage is that hypoxia inducible factors can increase red blood cells, for example it it will increase total hemoglobin to 120g, and make oxygenated hemoglobin reach 90g. At this time, the oxygen saturation is 90/120=75%.
Although 75% oxygen saturation appears low in high-altitude areas, the amount of oxygenated hemoglobin is sufficient for the body to use.