Clinically, one session of oxygen is usually about half an hour and costs about$10 to$15. According to the different hospital oxygen equipment is slightly different, some hospitals are oxygen cylinders oxygen, some are central oxygen supply oxygen. Mainly for patients with hypoxia in the body need oxygen to relieve the state, such as type I respiratory failure is mainly hypoxemia, type II respiratory failure hypoxemia accompanied by hypercapnia, this time the adjustment of oxygen flow rate is different, type I respiratory failure can be given to the concentration of oxygen for more than 30% or even 40% of the oxygen, according to the condition of the adjustment. Type II respiratory failure is generally low-flow continuous oxygen, giving low concentrations such as 30% or less oxygen concentration, low flow at about 1-2 liters per minute.