Arterial blood gas is the composition of gases dissolved in arterial blood. In a healthy person, the main gases are nitrogen, oxygen and carbon dioxide, of which the partial pressure of oxygen is 80-100 mmHg and the partial pressure of carbon dioxide is 35-45 mmHg. It can be used to determine whether there is respiratory dysfunction or acid-base balance imbalance. Patients with decreased oxygen saturation or shortness of breath need to be alerted to the presence of respiratory dysfunction or acid-base imbalance, and an arterial blood gas analysis is required. For example, ph greater than 7.45 is alkalosis, less than 7.35 is acidosis; pco2 higher than 45mmHg is hypercapnia, lower than 35mmHg is hypocapnia; oxygen partial pressure lower than 60mmHg suggests respiratory failure, and lower than 40mmHg is life-threatening. Arterial blood gas analysis is widely used in the clinic, for example, bronchial asthma, chronic obstructive pulmonary disease patients have no respiratory failure, it is through the arterial blood gas analysis to determine. Some endocrine diseases such as diabetes or chronic renal insufficiency, whether there is a metabolic acid-base imbalance, also through the arterial blood gas analysis to determine. Once there is an abnormal arterial blood gas analysis result, it is necessary to take appropriate treatment measures under the guidance of the doctor in conjunction with the patient’s condition.