The arterial blood gas test (ABG) is performed to determine how well an individual’s lungs are able to transport oxygen into the blood as well its ability to get rid of carbon dioxide from the blood. The arterial blood gas test (ABG) uses the blood from an artery to evaluate the (pH) acid levels and levels of both carbon dioxide and oxygen. When blood moves through the lungs, oxygen passes into it and carbon dioxide moves out from the blood and into the lungs. The ABG test is conducted using the blood from the artery, since oxygen and carbon dioxide levels must be measured before it enters body tissues.
The ABG test measures:
• (PaO2) - This is known as the partial pressure of oxygen. The ABG test assesses the pressure of oxygen present in the blood, and its ability to move from the lungs into the blood.
• (PaCO2) - This is known as the partial pressure of carbon dioxide. The ABG test assesses the levels of carbon dioxide present in the blood and its ability to move out of the body.
• pH - the ABG test assesses the levels of hydrogen ions (H+) in the blood. Under normal circumstances the pH of the blood is generally between 7.35 and 7.45.
The pH of the blood is known to be acidic if the pH is less than 7.0. If the pH of the blood is greater than 7.0 it is known to be alkaline or basic. The blood of a normal human being is believed to be slightly basic.
• Hydrogen carbonate (HCO3) hydrogen carbonate or bicarbonate is a chemical or a kind of buffer that prevents the pH of the blood from becoming too acidic or too alkaline.
• Oxygen content values (O2CT) and oxygen saturation values (O2SaT). The oxygen content which is a part of the ABG test assesses the amount of oxygen content in the blood, while oxygen saturation assesses the level and amount of hemoglobin in the red blood cells that is carrying oxygen.
Arterial Blood Gas Test Reasons
The arterial blood gas test is recommended by doctors in order to test for:
• The presence of severe lung conditions and respiratory disorders such as cystic fibrosis, chronic obstructive pulmonary disease and asthma.
• Ascertain treatment levels for lung disorders
• Check if extra oxygen is needed or if there is a need for mechanical ventilation or artificial breathing
• Check if the right amount of oxygen is being received when receiving oxygen in the hospital
• Assess the levels of acid-base in individuals who are experiencing heart disease, renal failure, uncontrolled polygenic disease, chronic and severe infections, and drug overdose and sleep disorders.
One of the biggest drawbacks of withdrawing blood from the artery is the level of discomfort and pain it causes, as arteries are set deeper in the body and are covered by nerves. If required doctors may administer a local anesthetic, especially if one is sensitive to pain or there is a hard time in finding the artery.