Significance of CO2 Levels in Blood

By Ashley | January 28, 2010

A certain amount of CO2 is present in everyone’s blood. It is in the liquid part of the blood called serum. There is a test that can be done to identify the levels of CO2 in the serum of the blood. The test that is done is a laboratory test and identifies the level of CO2 which is present in the form of bicarbonate in the serum of the blood.

Sometimes, more than the usual amount of CO2 is retained in the blood and it causes a physical and functional change in the body. This happens when too little CO2 is removed from the blood by the lungs. In such a case a condition called hypercapnia occurs, where there is an increased level of CO2 dissolved in the blood stream. This condition can cause certain illnesses such as rapid heart rate, seizures, coma, and heart attacks and in some cases, death. A decreased level of overall consciousness and respiratory difficulty is also noticed in people who have been retaining too much CO2 in their blood.

To test the level of CO2 in the blood, first a blood sample must be taken. It can be done during any part of the day. A health care worker cleans the inside of the patient’s elbow with an antiseptic liquid and then inserts a syringe to draw blood. As the syringe is air tight, no other gases can enter from the atmosphere. In case of infants or children, a sharp instrument called a lancet is used to draw blood and the blood is allowed to drip into a pipette. The place of puncture can later be sealed with a bandage. There are generally no side effects attached to this procedure, besides a slight discomfort at the puncture site for a little while.

For a certain number of hours before the test, maybe a day, it is advisable not to take any drugs, especially steroids or antacids as these drugs will alter the normal level of CO2 in the patient’s blood. CO2 level testing is done on an electrolyte panel. Changes in the CO2 level causes a change in the electrolyte balance of your body. It can be caused either by both, excessive retention and loss of CO2 from the blood stream. The organ in the body that is responsible for balancing the bicarbonate level in the blood is the kidney. Therefore, normal functioning of the kidneys play a vital role in maintaining the proper balance of CO2 in the blood.