MEASUREMENT OF OXYGEN SATURATION - PULSE OXIMETRY

Pulse oximetry is a non-invasive method for monitoring the oxygen saturation of hemoglobin in a person's blood (SO2).

Although the value of peripheral oxygen saturation (Sp O2) is not always identical with the value of arterial oxygen saturation (SaO2 blood gas analysis) from arterial gas analysis, the two are quite well correlated, so the pulse oximetry method is:

·       Safe, simple;

·       Convenient;

·       Non-invasive;

·       Cheap;

·       Valuable for clinical use.

WHAT IS MEASURED?

Oxygen enters the lungs and is then transmitted to the blood. Blood carries oxygen to the various organs in our body.

The main way oxygen is carried in our blood is through hemoglobin.

Oxygen saturation indicates the process in total hemoglobin that transports oxygen.

The oxygen saturation of the hemoglobin (SpO2) gives information about the breathing process (if it is efficient) and if the gazelles are changed normally.

HOW DOES IT WORK?

Pulse oximetry uses light to determine oxygen saturation. Light is emitted from sources that traverse the probe and reach the light detector.

If a finger is placed between the light source and the light detector, the light will now have to pass through the finger to reach the detector. Part of the light will be absorbed by the finger and the part that is not absorbed reaches the light detector.

The pulsiometer measures how much light hits the light detector. If there is more Hb in the finger, more light is absorbed.

NORMAL VALUES

·       Normal acceptable SpO2 ranges for patients without lung disease are 95% to 99%.

·       In infants and children, the SpO2 value is between 97-100%.

·       Values ​​below 90% indicate a lack of oxygen in the body.

·       At values ​​below 80%, visceral function is affected, the brain and heart being the first affected.

TYPES OF PULSE OXIMETER

Digital pulse oximeter

It can be used at home or in the hospital. On its screen it will display the oxygen saturation value and the pulse. It is mounted with the red light on the nail or on the earlobe.

Portable pulse oximeter

Usually used in hospitals. The display screen is no longer located on the clamp, but contains a cable that will connect to a monitor. It can be mounted on the finger, big toe, earlobe or in the palm of infants.

Integrated pulse oximeter

Complex monitors typically found in triage areas. The pulse oximetry curve is highlighted in blue.

There are mobile applications that can measure oxygen saturation with the help of the sensor near the mobile camera. Although the determinations cannot be considered precise, in certain situations it can provide information that can be helpful.

MEASUREMENT TECHNIQUE

·       Place the head of the sensor on the finger, with the red light at the level of the nail;

·       The positioning must be suitable, so that vasoconstriction does not occur, or it is wide;

·       The displayed value is read.



Last modified: Sunday, 27 November 2022, 10:13 AM