Arterial blood gas analysis; ABG; Hypoxia – ABG; Respiratory failure – ABG
Blood gases are a measurement of how much oxygen and carbon dioxide are in your blood. They also determine the acidity (pH) of your blood.
An arterial blood gas (ABG) test is a blood test that requires a sample from an artery in your body to measure the levels of oxygen and carbon dioxide in your blood. The test also checks the balance of acids and bases, known as the pH balance, in your blood
How the Test is Performed
Usually, blood is taken from an artery. In some cases, blood from a vein may be used.
Blood may be collected from one of the following arteries:
- Radial artery in the wrist
- Femoral artery in the groin
- Brachial artery in the arm
The health care provider may test circulation to the hand before taking a sample of blood from the wrist area.
The provider inserts a small needle through the skin into the artery. The sample is quickly sent to a laboratory for analysis.
How to Prepare for the Test
There is no special preparation. If you are on oxygen therapy, the oxygen concentration must remain constant for 20 minutes before the test.
Tell your provider if you are taking any blood-thinning medicines (anticoagulants), including aspirin.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.
Why the Test is Performed
The test is used to evaluate respiratory diseases and conditions that affect the lungs. It helps determine the effectiveness of oxygen therapy. The test also provides information about the body’s acid/base balance, which can reveal important clues about lung and kidney function and the body’s general metabolic state .
Normal Results
Values at sea level:
- Partial pressure of oxygen (PaO2): 75 to 100 mm Hg (10.5 to 13.5 kPa)
- Partial pressure of carbon dioxide (PaCO2): 38 to 42 mm Hg (5.1 to 5.6 kPa)
- Arterial blood pH: 7.38 to 7.42
- Oxygen saturation (SaO2): 94% to 100%
- Bicarbonate – (HCO3): 22 to 28 mEq/L
Note: mEq/L = milliequivalents per liter; mmHg = millimeters of mercury
At altitudes of 3,000 feet (900 meters) and higher, the oxygen value is lower.
Normal value ranges may vary slightly among different laboratories. Some laboratories use different measurements or may test different specimens. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
Abnormal results may be due to lung, kidney, or metabolic diseases. Head or neck injuries or other injuries that affect breathing can also lead to abnormal results.
Risks
There is very little risk when the procedure is done correctly. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.
Other risks associated with this test may include:
- Bleeding at the puncture site
- Blood flow problems at puncture site (rare)
- Bruising at the puncture site
- Delayed bleeding at the puncture site
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
FAQ
What is the ABG test normal range?
- The following are normal ranges for results of a blood gas test: pH: 7.35–7.45. partial pressure of oxygen (PaO2): 80–100 millimeters of mercury (mmHg) partial pressure of carbon dioxide: 35–45 mmHg.
Why is an arterial blood gas test done?
- An arterial blood gases test is done to check for severe breathing and lung problems. The test also checks how well treatments for lung problems are working. And the test can look for changes in how well your lungs, heart, or kidneys are working.
What did the analysis of the patient’s arterial blood gases reveal?
- Arterial blood gas analysis allows direct measurement of the quantity of carbon dioxide (PaCO2) and oxygen (PaO2) in the blood, results of which indicate how well the lungs are functioning.
What causes blood gases to be high?
- Abnormal results on any part of a blood gases test may be an indication of disruption of normal breathing. They can also reflect problems in the body’s system of regulating its acid-base balance. Too much acid in the blood is known as acidosis, and too much base is called alkalosis.
What is an ABG why or when is it usually performed?
- An arterial blood gas (ABG) test measures oxygen and carbon dioxide levels in your blood. It also measures your body’s acid-base (pH) level, which is usually in balance when you’re healthy. You may get this test if you’re in the hospital or if you have a serious injury or illness.
How do I get an ABG?
Continue to apply firm pressure to the puncture site for 3-5 minutes to reduce the risk of haematoma formation.
Dr. MD Harun Ar Rashid, FCPS, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including FCPS, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and community outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices.
