An arterial blood gas (ABG) test is the measurement of oxygen and carbon dioxide levels in the blood. It also measures your body’s acid-base (pH) level, which is usually in balance when you are healthy.
If you are in the hospital or you have a serious injury or illness, you may have this test.
The test gives your doctor a clue as to how well your lungs, heart, and kidneys are functioning. You will probably get other tests with this.
Every cell in the human body needs oxygen to live. When we breathe (breath) and exhale (exhale), our lungs carry oxygen to the blood and expel carbon dioxide. That process, called gas exchange, provides the oxygen we (and all our cells) need to survive.
If anybody is having trouble breathing, then the doctor may use an arterial blood gas (ABG) test to help diagnose the problem.
Reason to do the arterial blood gas (ABG) test
The doctor may order an arterial blood gas test:
- To check for severity of breathing and lung problems, such as asthma, cystic fibrosis, or chronic obstructive pulmonary disease (COPD)
- Examine how treatments for your lung problems are working
- Check to see if you need extra oxygen or other help to breathe.
- Check your acid-base balance. Your body may have too much acid due to kidney failure, severe infection, specific toxic ingestion, diabetes complications (CAD), or poorly treated sleep apnea.
What happens during this test?
You will likely have an arterial blood gas test done in a hospital, but it can be done in OPD also.
Your doctor or other health care professional will use a small needle to pull some part of your blood, usually from your wrist. Sometimes they take it from the artery inside your arm, above your waist, or above the elbow.
Before an arterial blood gas test, the arteries in your wrist may be pressurized for several seconds. The procedure, called the modified Allen test, checks that the blood flow in your hand is normal.
When you are preparing for an atrial blood gas test, explain every medication you are taking such as supplements, and vitamins, etc.
If you are receiving oxygen therapy but can breathe without it, your oxygen may be cut off for 20 minutes before the blood gas test for a “room air” test.
There can be discomforts during or after the test. Typically, drawing blood from an artery causes more pain than drawing blood from a vein. The arteries are deeper than the veins and there are sensitive veins nearby.
You may feel light, weak, dizzy, or nauseous while you are bleeding. The technician will tell you to gently press on the area for a few minutes after the needle has been taken out, this can avoid injury.
Indication of Test Result
Arterial blood gas test results are usually available in less than 15 minutes. But your doctor cannot diagnose it on the basis of a thorough arterial blood gas test. So they will probably do other tests as well.
Your arterial blood gas test results may show if:
- You are getting enough oxygen
- Your lungs are extracting enough carbon dioxide.
- Your kidneys are working properly.
The number of common results varies. There may be several reasons that your number may not be in this range, including illness or injury that affects your breathing. Your doctor will explain your ABG results in relation to your medical history and current condition. Your ABG results will affect your diagnosis and treatment.
(Disclaimer: Information provided in this piece of article is purely for educational purposes only. All results must be clinically correlated with the patient’s data to make an accurate diagnosis.)