Blood gas analysis is one of the diagnostic methods. Among other things, it provides insight into the gas distribution of carbon dioxide and oxygen.
What is blood gas analysis?
Blood gas analysis is among the diagnostic methods. Among other things, it provides insight into the gas distribution of carbon dioxide and oxygen. Blood gas analysis is performed by drawing blood. For this purpose, a small prick is made on the fingertip or earlobe of the test person. Blood gas analysis (BGA) is an examination of the blood. This procedure involves measuring the amount of oxygen and carbon dioxide within the blood. This provides the examining physician with information about the health of the heart and lungs. For example, the blood may become “acidic” due to an excess of carbon dioxide or a deficiency of oxygen. In addition, blood gas analysis is used to determine the pH value. Furthermore, it is used for various metabolic diseases in order to either detect or control them. Blood gas analysis is usually performed on arterial blood, which is normally obtained from the femoral or radial artery by arterial puncture, or on capillary blood taken from the fingertip. In the case of special questions, an examination of venous blood is also possible. The blood sample is evaluated by machines. Normally, the test result is available after only a few minutes. The BGA devices are suitable for immediate diagnostics close to the patient.
Function, effect and goals
When a person breathes in, oxygen (O2) enters his lungs. When he exhales, on the other hand, he releases carbon dioxide (CO2). The respiratory process continues within the body. Thus, the oxygen binds to the red blood cells. It is also transported to the organs, where it is exchanged for carbon dioxide, which flows back to the lungs with the blood. There, the person then exhales it. Partial control of the acid-base balance also takes place via the carbon dioxide. For this reason, the acid-base balance can also be recorded with the blood gases. If shortness of breath occurs, the doctor can use a blood gas analysis to determine whether this is caused by a lack of oxygen and the extent of this. A blood gas analysis is performed on people who suffer from severe respiratory and pulmonary dysfunction. If, for example, the circulation collapses, the emergency physician determines the oxygen saturation by blood gas analysis. A blood gas analysis is also important for people with certain metabolic diseases, as they require regular examinations. Blood gas levels can also be affected by chronic kidney disease. Sometimes the blood is also affected by harmless infections such as a stomach flu, which increases the blood values. The reason for this is a loss of fluid. It occurs due to diarrhea and vomiting. If a person spends time in the mountains, this temporarily causes blood levels to be too low. Thus, the level of oxygen in the mountains is lower than usual. There is no need to worry, however, because the value returns to normal as soon as the person returns to his or her usual environment. Regular blood gas analysis is also carried out on coma patients who are artificially ventilated. Doctors primarily check the level of oxygen. This control allows the patient to be ventilated effectively. An increase in the amount of oxygen takes place if the oxygen level is too low. A blood gas analysis is performed by drawing blood. For this purpose, a small prick is made on the fingertip or earlobe of the test person. An arterial blood sample can also be taken, but this is more uncomfortable for the patient. Thus, the physician must draw the blood from a forearm artery, for which he uses a hollow needle. The thin needle is inserted into the artery and the blood enters a hollow tube. To prevent secondary bleeding, the patient presses a cotton swab firmly on the puncture site for a few minutes. Thanks to modern medical methods, a blood gas analysis is now also possible without drawing blood. For this purpose, the patient is given a special chip that resembles a clothespin. This is attached to the patient’s fingertip. On one side of the clip there is a light source that shines through the finger.On the other side, the clip is equipped with a photoelectrode from which the number of light components is measured. The clip is connected to a computer, which has the function of determining the saturation value. Such a clip is usually used in an intensive care unit, where the patient is monitored around the clock. Ambulances of emergency physicians also have such a clip. The blood taken is analyzed in a laboratory device within 60 minutes. Once the device has completed the analysis, it prints it out via a connected printer. The physician can then view the test result.
Risks, side effects, and hazards
There are no major side effects to worry about from a blood gas analysis. In some people, the puncture site can sometimes become infected. If arterial blood is drawn, there is a risk of bruising (hematoma). However, since this is harmless, it goes away on its own after a few days. If necessary, the affected person receives an ointment from the doctor. By applying it, the bruise disappears more quickly. If a clip is used for blood gas analysis, there are no side effects at all. The cost of a blood gas analysis is covered by health insurance. It makes no difference whether the analysis is performed in a hospital or by the attending physician. If an operation is to take place, a corresponding fitness test must first be carried out, which also includes a blood gas analysis. The costs for this ABG are also covered by the health insurance companies.
