A high level of blood gas may indicate a serious medical condition, such as sepsis, a heart attack, or a stroke.
There are two ways of measuring blood gas:
- Arterial blood gas (ABG)
- Venous blood gas (VBG)
In this article, we are going to take a look at the differences between the two of them.
| ABG | VBG |
| Arterial blood gas. | Venous blood gas. |
| Measures the levels of oxygen and carbon dioxide in the arterial blood. | Measures the levels of oxygen and carbon dioxide in venous blood. |
| Considered as more accurate. | Considered as less accurate. |
| Used to assess the severity of a person’s illness. | Used to monitor a person’s progress in treatment. |
| Blood drawn from an artery, typically in the wrist. | Blood drawn from a vein, typically in the arm. |
| Higher risk of complications in people with heart problems or diabetes. | Lesser risk of complications. |
The main difference between an arterial blood gas (ABG) and a venous blood gas (VBG) is that an ABG measures the levels of oxygen and carbon dioxide in arterial blood, while a VBG measures the levels of oxygen and carbon dioxide in venous blood.
Arterial blood has a higher level of oxygen and a lower level of carbon dioxide than venous blood.
Blood gas measurements are used to determine how well a person’s lungs are working and to see how well the person’s body is using oxygen.
Higher levels of oxygen in arterial blood is beneficial for the body as it helps to meet the body’s metabolic needs. A lower level of carbon dioxide in arterial blood is also beneficial as it helps to maintain the pH balance of the body.
A VBG is a less accurate measure of the levels of oxygen and carbon dioxide in the blood than an ABG. This is because the levels of oxygen and carbon dioxide in venous blood are not as representative of the levels in arterial blood as the levels in arterial blood are of the levels in the rest of the body.
ABG measurements are typically used to assess the severity of a person’s illness, while VBG measurements are used to monitor a person’s progress in treatment.
In some cases, a VBG may be used in place of an ABG if an ABG is not available. Doctors will typically order an ABG if they need a more accurate reading of a person’s oxygen and carbon dioxide levels.
Illness such as pneumonia, sepsis, and heart failure can cause the levels of oxygen and carbon dioxide in the blood to change, so it is important for doctors to be able to accurately measure these levels.
For VBG measurements, a person’s blood is drawn from a vein, typically in the arm. For ABG measurements, a person’s blood is drawn from an artery, typically in the wrist.
People with a history of heart problems or diabetes are at a higher risk of experiencing complications related to an ABG measurement. That’s why a VBG may be ordered instead.
