Oxygen Saturation Is Important

As we all know, oxygen saturation is an important physiological parameter to reflect the respiratory function. The clinical application of oxygen saturation monitoring in internal medicine, surgery, intensive care unit and so on is very common. It is more routine and important for respiratory department Monitoring means. The author's department often receive emergency consultation in other departments, ask the patient what is the situation now, why emergency consultation? The answer is mostly because of low oxygen saturation, so urgent consultation. We all know that low oxygen saturation and respiratory department can not be related, but not all reduced oxygen saturation caused by respiratory diseases, so only find the root cause of oxygen saturation, to make the appropriate treatment to make oxygen saturation Degree rebounded.

What is oxygen saturation?

Oxygen saturation is the degree to which hemoglobin (Hb) binds to oxygen, ie the percentage of oxygen and Hb to total Hb, or the ratio of Hb bound oxygen to Hb oxygen capacity.

The formula is as follows: SpO2 = HbO2 / (HbO2 + Hb) × 100%. Normal oxygen saturation of 95% -98%, oxygen saturation and partial pressure of oxygen directly related.

Oxygen saturation detection method

Oxygen saturation measurement is usually divided into two types of electrochemical and optical methods.

Electrochemical method that the human body to adopt artificial blood, blood gas analyzer and then measured oxygen saturation value, which is an invasive measurement method, and can not be monitored continuously.

Optical measurement is a non-invasive method using a photoelectric sensor based on the principle that arterial blood absorbs light as the pulse of the artery changes. The most commonly used method is the pulse oximeter. One side of the instrument probe is fitted with two LEDs, emitting red and infrared light respectively, and the other is equipped with a photodetector that converts the detected red and infrared light transmitted through the finger artery into electrical signals. Since the absorption coefficients of these two lights are constant for the skin, muscle, fat, venous blood, pigment and bones, only the concentration of HbO2 and Hb in the arterial blood flow changes periodically with the arterial blood, causing the photoelectric detection The signal intensity of the output of the device changes periodically. After these cyclically changed signals are processed, the corresponding oxygen saturation can be measured and the pulse rate can be calculated as well.