Arterial Blood Gas (ABG) Test: Procedure and Need For The Test

Submitted on March 27, 2012

What Is Arterial Blood Gas?

Arterial blood gas is a blood test that is undertaken to study the levels of acidity, oxygen and carbon dioxide in the blood before it is transported to the tissues. The blood sample is collected and tested in a laboratory. By interpreting arterial blood gases test results, doctors can determine the state of the body's lung and kidney function.


Arterial blood gas analysis is widely available in hospitals. During most blood testing procedures, blood is drawn from a vein. But at this point the oxygen content in the blood is used up by the tissues. Therefore in an arterial blood gas test, the blood sample is drawn from an artery; at this point the blood hasn't reached the tissues, preserving the blood's oxygen content.

The obtained blood sample is then taken to the lab for testing. Once all the bubbles are eliminated the syringe is sealed and placed in ice. This is done to slow the metabolic process. This is important for maintaining the accuracy of the results. The blood is then analyzed carefully, determining the acidity of the blood, the amount and pressure of oxygen and carbon dioxide and bicarbonate levels.

Analysis of Arterial Blood Gas Testing

The analysis of arterial blood gas values shed light on the following:

  • When a patient presents symptoms like hyperventilation, chest pain, dizziness, etc. it can be hard to pinpoint the root cause. Many disorders display the same symptoms. Using an arterial blood gas tests help doctors discover whether the symptoms are a result of metabolic disorders, respiratory disorders, etc.
  • It helps doctors monitor lung function and determine future medical course. This test comes in very handy in case of patients going through special medical procedures like heart surgery. Using this test doctors can gauge the ability of the lungs to cope during and after the procedure; how well the body will cope on a heart-lung machine.
  • It helps monitor and follow the body's metabolic system. An imbalanced metabolism can be the cause of a number of serious disorders and illnesses.
  • Neonatal arterial blood gases test is crucial in monitoring the progress of a premature baby. It helps doctors adjust an appropriate oxygen levels. If the oxygen content is too high, it can result in lung and vision disorders.
  • It determines kidney functions and acid balance of the body.

The test uses a complex formula. The final analysis requires the use of an arterial blood gas calculator to derive an accurate interpretation.