VERIFIED CONTENTAuthor: lek. Tomasz Nęcki

Saturation is a word that has been in the medical language for a long time, but patients began to encounter it widely when the world was engulfed by the COVID-19 pandemic. What is blood saturation, how can it be measured, what is the correct oxygen saturation and why is the blood saturation measurement so important?

What is saturation?

The termsaturationderives from the Latin wordsaturatioand this term means the saturation of a liquid with some gas.

This term is most often used in relation to the oxygen saturation of arterial blood - in this context the termblood saturationis used (the parameter is abbreviated asSpO2).

In the medical worldsaturation measurementis a widely performed study, but patients began to devote much more attention to it in 2022, when the COVID-19 pandemic hit the world.

Saturation: measurement

At the very beginning, it is worth emphasizing one aspect, probably important for many patients - the measurement of saturation is non-invasive and painless. It is performed using a small device, which is apulse oximeter.

Typically, the device for measuring oxygen saturation is put on the finger, but it is possible to determine the oxygen saturation of arterial blood by putting the device on, for example, a lobe of the auricle or the wing of the nose. Saturation in a baby or a newborn baby is sometimes measured by putting a measuring apparatus on their feet.

The measurement of saturation is short - usually it only takes a few to several seconds.

Pulse oximeters are devices that emit various wavelengths that are then absorbed by red blood cells (erythrocytes). These cells contain hemoglobin responsible for the transport of oxygen, which reflects the radiation differently when it is oxygenated and differently when it is deoxygenated.

It is thanks to the existence of such differences in radiation absorption that it is possible to determine arterial blood saturation using pulse oximeters.

Saturation: indications for the test

Saturation testing is commonly performed in hospital treatment -Pulse oximeters are used during various surgical procedures, but also during diagnostic tests (such as bronchoscopy).

Saturation is marked as:

  • in coma patients,
  • in patients monitored for various other reasons (e.g. after some operations),
  • in babies born prematurely,
  • in people with various respiratory diseases (both acute and chronic),
  • in people undergoing oxygen therapy.

Saturation: norm

What should the saturation be like? Correct saturation, in proper conditions, should be between 95 and 98%.

The age of the respondent has some influence on the level of saturation - in the elderly, the correct level of saturation may be slightly lower in young adults and children.

It is worth emphasizing here that the saturation values ​​reaching 99-100% are found only in patients undergoing oxygen therapy.

Low saturation: possible reasons for its reduction

When detecting reduced saturation, first and foremost, you should take into account possible factors that may result in obtaining a false measurement result.

Inconsistent with the reality of the pulse oximeter may result, for example, from the presence of varnish on the nails - the device should be applied to clean, unchanged (including disease-free, e.g. fungal) nails.

The test results may also be distorted by significant cooling of the limbs or their excessive trembling.

Saturation in smoker

It is worth emphasizing that people who smoke cigarettes by default may have lower saturation than those who do not use this type of stimulant.

Life-threatening saturation

Saturation less than or equal to 94% should pay attention - when it drops below 90%, we can speak of respiratory failure. It's a life-threatening saturation. The condition is serious because insufficient oxygen in the body can even lead to permanent damage to extremely important organs such as the heart and brain.

Check also :

  • Coronary heart disease: symptoms.
  • Brain hypoxia: causes, symptoms, treatment

There are many reasons for the decrease in saturation. First of all, this problem can be caused by respiratory diseases - both acute and chronic.

The decrease in saturation can be observed in patients with:

  • acute respiratory failure,
  • chronic obstructive pulmonary disease,
  • asthma,
  • cystic fibrosis (especially during theirexacerbations).

In newborns, low saturation may be associated with congenital cardiovascular defects.

In 2022 and 2022, however, the most talked about is the relationship between low saturation and COVID-19 disease.

Saturation and COVID-19

causing COVID-19SARS-CoV-2 coronavirushas, inter alia, the ability to damage the structures of the respiratory system, which undoubtedly affects the course of gas exchange in the lungs. This may result in a decrease in saturation.

In some patients it leads to the occurrence of:

  • severe shortness of breath,
  • anxiety,
  • increased heart rate
  • and other symptoms suggesting respiratory failure,

, however, it sometimes happens that the patient has low oxygen saturation, and at the same time he does not feel any discomfort because of it. The last of these possibilities is particularly dangerous and that is why some doctors have recently urged patients to regularly measure the saturation.

There are already numerous reports that patients with COVID-19 who struggle with hidden hypoxia - an asymptomatic drop in saturation - may have a worse prognosis.

The lack of ailments related to respiratory failure does not mean that the patient is safe - at this time, damage to the most important organs of the human body may occur anyway.

Due to this risk, currently, in the time of the COVID-19 pandemic, monitoring of saturation becomes particularly important - it is especially important in people infected with SARS-CoV-2, in whom a sudden decrease in saturation suggests the need to contact with a doctor.

Saturation and dyspnea

It is worth mentioning here the link between saturation and dyspnea - it is not as unambiguous as you might suppose.

Dyspnoeais defined as a subjective feeling of lack of air or inability to inhale. It can have various causes - it can occur due to respiratory system disease and hypoxia, but it can also occur, for example, in the course of various anxiety disorders (especially during anxiety attacks). Dyspnea alone is not synonymous with a decrease in saturation, while a decrease in saturation usually - but not always - leads to a greater or lesser degree of dyspnea.

  • Normal blood pressure. Blood pressure norm
  • Blood morphology - how to read the result?
  • Angina pectoris (angina pectoris) - causes, symptoms, treatment
Bow.Tomasz NęckiA graduate of the medical faculty at the Medical University of Poznań. An admirer of the Polish sea (most willingly strolling along its shores with headphones in his ears), cats and books. In working with patients, he focuses on always listening to them and spending as much time as they need.

Category:

Respiratory system