Pulse oximetry is the oxygen saturation detected at the end of the hand, which can indirectly reflect whether the body is hypoxic or not, and its normal value is more than 94%. If the value is lower than normal, it is considered that the body is in a state of hypoxia, and it is necessary to give oxygen treatment, and at the same time, it should monitor the blood pressure, and the systolic blood pressure is lower than 80mmHg, suggesting the existence of hypovolumic shock, and it is necessary to use vasoactive drugs as soon as possible, such as epinephrine or norepinephrine, and at the same time, increase the amount of oxygen, and periodically review the blood pressure and monitor the oxygen saturation, respiration, and heart rate. When testing the need to pay attention to can not be long time clip the same finger, otherwise the detection of the value of a certain error, because it is easy to lead to the finger of the local blood circulation is insufficient, will affect the finger pulse oxygen value, can be exchanged for more than one finger testing, and at the same time, diligent use of warm water to wipe wash.