Reasons, Procedure and Preparation For Base Excess Arterial Blood Test

By Ashley | December 3, 2009

Our blood serves as a carrier for basically every substance that we ingest to our tissues. To facilitate this, the blood needs to be in a certain condition and one of the measures or rather values that are considered would be the pH value. This actually applies to the whole body as well but testing levels of pH is much easier to do than other tests. One of the most comprehensive tests on the condition of the blood is the Arterial Blood Gas test. This is a test that measures an entire bunch of factors about the chemistry of the blood. One of the measurements is that of base excess in arterial blood. The base excess Arterial Blood Gas test is a test that is done for the level of acidity of the blood. The base excess is defined as the amount of acid that it would take to bring the ph level of the blood back to normal. An elevated level indicates a state of alkalosis and negative reading indicates acidosis.

Reasons

The arterial blood gases base excess test is performed to quickly analyze the amount of acid content in the blood. Our bodies need to be in a certain equilibrium to perform optimally. This reference range is set between -5 to +3. Anything that is outside the boundaries of this range indicates either acidosis or alkalosis.

Procedure

The arterial blood gas test is performed by sticking a syringe into the radial artery and pulling out a blood sample. All gas must be removed from the syringe and then placed in a special analyzer. The analyzer will then give immediate results for levels. Note that the arterial blood gases test is not just a test for base excess but also a test for dissolved gases.

Preparation

There is no special preparation that you need to do for this test as it is a test that is done to ascertain that on-the-spot status of the blood. Dissolved gases that are measured include carbon dioxide levels. These levels will also correspond to bicarbonate levels. Bicarbonate is a substance that is created in the kidneys from dissolved carbon dioxide in the blood. pH levels are extremely important to measure because the body can only tolerate a certain range of pH variations. Variations that are beyond the normal range can end up causing serious damage to the central nervous system with the destruction of nerve cells.