The oxygen saturation
What is oxygen saturation?
The oxygen saturation describes the percentage of the red blood pigment (hemoglobin) that is loaded with oxygen. It is important to assess the respiratory function.
Oxygen saturation can be influenced by various factors. Age is an important variable. In children and young adults, saturation should be 100%, whereas it can drop to 90% with age. The pH value, the temperature and the carbon dioxide concentration also play a role.
In addition to the individual variables, different clinical pictures (COPD, heart failure, etc.) can have a negative impact on oxygen saturation.
Where can you measure oxygen saturation everywhere?
There are two methods of determining oxygen saturation. The simple measurement is made with a pulse oximeter - a small device that records the absorption of light and thus indicates the oxygen saturation. The pulse oximeter can be attached to a finger or to the earlobe. After a short time, the value is shown on the display. However, measurement errors can occur with this method, which is why blood gas analysis is ideal for more precise examinations.
For the blood gas analysis, blood is taken from the patient from an artery. The collection is usually made from an artery located on the wrist. During this analysis, parameters such as oxygen saturation, carbon dioxide partial pressure and the acid-base balance are recorded. This allows a comprehensive diagnosis and allows conclusions to be drawn about the underlying disease.
Find out all about the topic here: The blood gas analysis.
When should you monitor oxygen saturation?
The oxygen saturation is routinely monitored by an anesthetist (anesthetist) during each anesthesia. During anesthesia, the patient is artificially ventilated, which is why saturation is an important parameter in order to determine whether the patient's tissue or organs are adequately supplied with oxygen.
Furthermore, the oxygen saturation in intensive care and emergency medicine is checked using a monitor. In emergency medicine, you want to get an impression of the patient and the functions of his body's circulation. The respiratory function can be assessed through the oxygen saturation. If necessary, oxygen can also be supplied to the patient.
In intensive care medicine, on the other hand, patients are usually unstable and breathing is restricted. In this case, oxygen must be supplied. The amount required for this can be calculated based on the oxygen saturation.
In addition, patients suffering from chronic lung diseases should be monitored. These include diseases such as COPD, bronchitis, bronchial asthma or cystic fibrosis (congenital metabolic disease). But other diseases, such as heart failure, can also have a negative effect on satiety. If the oxygen saturation is poor or drops, oxygen can be supplied to the patient. This is especially important in patients with end-stage COPD. They have to independently control their saturation at home and adjust their oxygen demand.
Find out more about the topic here: The therapy of COPD.
These measuring devices are available
There are many different measuring devices on the market. Pulse oximeters are suitable for household use. These are small devices that have a measuring clip that can be attached to a finger or the earlobe.
In order to find the optimal device for your use, you should ask your treating doctor or consult the respective customer reviews on the Internet.
The process of measuring saturation
The process differs depending on how the oxygen saturation is determined. When measuring with a pulse oximeter, it is simply attached to the finger or the earlobe. After a short time the device beeps and displays a value.
If saturation is determined by blood gas analysis, blood must be drawn from an artery. The doctor looks for a suitable artery for this, usually on the wrist. This artery is then punctured and the blood examined. The analysis of the blood is done by machine. After a few minutes you will get the desired values.
Read more on the following topic: The blood gas analysis.
The evaluation
The pulse oximeter is evaluated within seconds. The principle is based on a measurement of the light absorption. There is a light source on one side of the device and a sensor on the other. This sensor can measure absorbance, which is dependent on the hemoglobin concentration.
The evaluation of a blood gas analysis is quite complex and is carried out using a special device. The device is only suitable for clinical use. The oxygen saturation can also be determined quickly by a blood gas analysis.
The norms of oxygen saturation
The normal values in young adults are between 96% and 100%. In old age, this value is usually lower because the oxygen partial pressure drops.
Values from 90% and below are in need of treatment. However, disturbances in oxygen saturation can be tolerated to different degrees. For this reason, one should consider separately for each patient whether a therapy is necessary. However, values below 85% are particularly critical and must be dealt with as quickly as possible.
Oxygen saturation below 90% - what does that mean?
The normal values are in a range between 96% and 100%. From a certain age or with certain illnesses, satiety may be reduced. In general, oxygen saturations of up to 90% can be tolerated. Values below 90% should be treated. But what leads to a reduced saturation?
Diseases that damage the lung tissue lead to a restriction in breathing. This reduces the oxygen content in the lungs and the hemoglobin (red blood pigment) can no longer be adequately loaded with oxygen. As a result, the cells in the various organs can no longer be adequately supplied with oxygen and perish. For this reason, it is important to provide oxygen to the patient.
The most common lung diseases are COPD, bronchial asthma and lung cancer. In addition to diseases of the lungs, circulatory disorders, heart failure and disorders of the acid-base balance can also lead to decreased saturation. Poisoning, such as carbon monoxide poisoning, is also conceivable. In this case, the saturation does not decrease chronically and progressively but very quickly in a short time.
How do you recognize lung cancer? You can find more information here.
Read more on the subject at: Decreased oxygen saturation
When does oxygen saturation become critical?
The oxygen saturation becomes critical from a value of 85% and below. The hemoglobin (red blood pigment) can no longer be adequately loaded with oxygen, so that the cells in the body receive too little oxygen and perish. If left untreated, the tissue can become so damaged that it cannot recover. This condition is irreversible. Organs such as the brain or heart, which have a high demand for oxygen, are particularly sensitive to such damage.
Values above 90% and below should also be treated, but they are not particularly critical.
What can you do to increase oxygen saturation?
There are several options available to increase oxygen saturation. One should start with a lifestyle change. Smokers should definitely give up smoking. If you are overweight, it is advisable to lose weight and exercise regularly. Recommended sports are yoga, slow jogging, and cycling. Yoga in particular promotes conscious awareness of breathing and can improve efficiency and satiety. Furthermore, walks or stays in the fresh air in general are recommended.
If these changes do not lead to a sufficient improvement, further measures can be taken. If the values are permanently reduced, oxygen can also be added. This is done using oxygen glasses, which deliver the oxygen from special bottles directly to the nose. Usually the patients feel more vital and are more productive. Small, portable oxygen bottles are now also available, so you don't have to worry about being tied to the bed. Special medications can also be prescribed to improve lung function. These can be inhaled corticosteroids or beta-2 agonists. Corticosteroids reduce inflammation and prevent potential infections. Beta-2 agonists, such as salbutamol, widen the bronchi and make breathing easier.
The therapy options are constantly improving, for this reason it is advisable to go to the doctor regularly and seek advice.
These articles might also interest you:
- The therapy of COPD
- The therapy of asthma
The cost of oxygen saturation
The cost of oxygen saturation can vary greatly depending on the underlying disease. If you want to buy a pulse oximeter to be able to check saturation at home, you have to reckon with costs between 30 and 100 euros. Most of the devices are in this price range.
The cost of an additional supply of oxygen can be quite expensive. However, these costs are covered by the insurance, as oxygen is only prescribed by the doctor when it is necessary.
What are the alternatives?
If there is damage to the lungs that requires an additional supply of oxygen, there are no longer any alternatives. Through drug therapy and lifestyle changes, lung function can be improved to a certain extent - but none of this can replace the function of oxygen.
