The very low oxygen content in the blood and the clinical measures to be taken depend mainly on the different types of hypoxic states. Low oxygen content in blood can cause two different conditions, one is hypoxemia, which is also type I respiratory failure, and oxygen should be given, taking a medium to high concentration of oxygen, giving a continuous relatively high flow of oxygen, the oxygen concentration can reach about 40%, and the oxygen flow can reach about 2-4L/min. The other type is hypercapnia with hypoxemia, that is, type II respiratory failure, which should take continuous low-flow and low-concentration oxygen, with oxygen concentration controlled at about 30% and oxygen flow rate generally around 1-2L/min.