SpO2 on the monitor represents fingertip oxygen saturation, the value changes can reflect whether the patient’s body is in a state of hypoxia, and can reflect the patient’s respiratory function and arterial oxygen changes to a certain extent, is used to help doctors better monitor the patient’s basic vital signs important indicators. normal value of SpO2 should be greater than 94%, the upper limit is 100%. When SpO2 is less than 94%, the patient may show different degrees of hypoxia, such as shortness of breath and chest tightness. When SpO2 continues to drop less than 90% or even less than 80%, it indicates that the patient has severe hypoxemia, which can affect the normal function of the organism to a greater extent. When a patient has abnormal SpO2, it is mostly considered as respiratory disease or cardiovascular disease, such as lung inflammation, chronic obstructive pulmonary disease, and severe pulmonary fibrosis, asthma persistence, respiratory distress syndrome, etc. When there are problems such as decreased cardiac function and cardiac arrest, it can also lead to a rapid decrease in oxygen saturation, which needs to be corrected by timely oxygen therapy or application of drugs. In addition, the cardiac monitor can also monitor the patient’s heartbeat, blood pressure and other indicators at the same time. When the value is abnormal, it should be combined with the patient’s symptoms, as well as improve other related tests, comprehensive analysis, and help the patient solve the problem as soon as possible, so as not to aggravate the condition and affect the prognosis.