What is SPO2 indicator?

Vital signs are numbers measured using various devices and techniques to assess basic bodily functions. There are four traditional vital signs: pulse, temperature, breathing rate, and blood pressure. However, now many researchers have mentioned a fifth vital sign, which is the SpO2 index.

Oxygen is essential for human life. When we breathe, oxygen enters the lungs. Blood and hemoglobin (the most important component of blood) will transport oxygen from the lungs to all parts of the body to ensure life. This transport takes place when hemoglobin (Hb) combines with oxygen to form HbO2.
A hemoglobin molecule can combine with 4 oxygen molecules, when enough 4 oxygen molecules are attached, it is called oxygen saturation. The SpO2 index, also known as blood oxygen saturation, represents the ratio of oxygenated hemoglobin to the total amount of hemoglobin in the blood. If all the hemoglobin molecules in the blood are attached to oxygen, then the oxygen saturation is 100%. In a normal healthy person, arterial oxygen saturation ranges between 95 - 100%. Blood oxygen saturation below 90% is low.
SpO2 index is considered one of the vital signs of the body, besides other signs are temperature, pulse, breathing rate and blood pressure. When the body is deprived of blood oxygen, organs such as the heart, liver, brain, ... will quickly suffer negative effects. Therefore, it is necessary to monitor the SpO2 index regularly to promptly intervene if a dangerous situation occurs.

2.1 In emergency resuscitation SpO2 is the first basic survival index in monitoring critically ill patients. Through the SpO2 index displayed by the SpO2 machine, the doctor can assess the patient's health status, especially for patients who have to be on ventilators or oxygen.
2.2 Detecting CO poisoning CO is a toxic gas, which is often found when burning coal. CO replaces oxygen at the iron binding site on the Hb molecule, so CO poisoning will increase COHb (carbon monoxide-bound hemoglobin) and decrease HbO2 (oxygen-bound hemoglobin). This phenomenon reduces the saturation of oxygen in the blood. The patient's blood will be taken to the laboratory with a SpO2 meter to accurately diagnose whether the patient has CO poisoning.

2.3 Diagnosing Low Blood Pressure SpO2 is an accurate reflection of blood pressure drop as low as 30mmHg (low blood pressure). In case the SpO2 reading of the finger is in doubt about the accuracy, the doctor can use the SpO2 index probe on the patient's forehead because it responds more quickly to the SpO2 change.
2.4 Diagnosis of anemia Anemia is a condition in which the hemoglobin in the blood falls below the normal level. In the absence of hypoxia, pulse oximeter will give accurate SpO2 readings when the hemoglobin concentration drops to 2 - 3g/dL.
2.5 Detection of Hypoventilation Clinical trials have shown that the SpO2 index is a sensitive marker for the assessment of ventilation status when the patient is breathing normally (not for assessment when the patient is receiving oxygen support. aid).
2.6 Support for the treatment of many respiratory diseases Patients with SpO2 measurement below 93%, assessed as hypoxic, need oxygen or blood breathing (if the patient cannot breathe on their own). Or, patients who are working in a secretive environment, lacking oxygen such as factories, incinerators, ore mines, etc., when they go out into an open environment with lots of oxygen, they will be supplemented with oxygen when breathing and the doctor will adjust the amount of oxygen. Let the patient breathe until the SpO2 index is stable at 97 - 100%. The level of oxygen used by the patient continues to be maintained until their breathing is stable again. And this process cannot ignore the role of the SpO2 meter.
SpO2 index plays an extremely important role for each person's health. The monitoring of SpO2 index should be done regularly so that the patient knows the amount of oxygen in the blood, knows when more oxygen is needed for the body and takes timely response measures when in a dangerous situation.