Arterial Blood Gases
Definition |
Body Parts Involved |
Reasons for Procedure |
Complications |
What to Expect |
Outcome |
Call Doctor If
Definition
A blood test to identify the levels of certain gases that are indicators of lung and kidney function.
Parts of the Body Involved
Blood and an artery in the wrist, arm, or groin
Reasons for Procedure
This test determines the amount of oxygen and carbon dioxide dissolved in the blood, as well as the acid/base status. Oxygen and carbon dioxide levels are indicators of lung function, and the acid/base status provides information on how well the kidneys are functioning.
This test helps evaluate respiratory problems, such as asthma, and other conditions that affect the lungs. If you are undergoing oxygen therapy, this test will determine whether or not the therapy is effective.
Risk Factors for Complications during the Procedure
None
What to Expect
Prior to Procedure - If the blood is going to be taken from an artery in the arm, an Allen test will be done to evaluate blood circulation. The Allen test involves pressing the radial and ulnar arteries in the wrist, which causes the palm to turn white. When the arteries are released, the skin turns pink and flush. Failure to flush within five seconds will indicate decreased blood flow, and another site for puncture will be selected.
Anesthesia -None
Description of the Procedure - The puncture site is swabbed clean, the needle is inserted into the selected artery, and blood is withdrawn. The needle is then removed.
After Procedure -The puncture site should be compressed for a minimum of five minutes to stop the bleeding. If you have recently taken aspirin or other blood-thinning medications, it will take longer for the bleeding to stop. Once blood flow has stopped, a bandage will be placed on the puncture site, and should not be removed for at least 30-60 minutes.
How Long Will It Take? About 15 minutes, including preparation, blood draw, and compression.
Will It Hurt? There may be some discomfort during insertion of the needle.
Possible Complications:
Complications from an arterial blood draw are fairly rare. They include:
- Delayed bleeding
- Bruising
- Circulation impairment
- Injury to the artery
Average Hospital Stay - None
Postoperative Care - Keep the puncture site clean and protected until it heals.
Outcome
Based on the test results, which should be available quickly, your doctor can assess your lung and kidney function. Normal results are:
Partial pressure of oxygen (PaO2) | 75 – 100 mm HG |
Partial pressure of carbon dioxide (PaCO2) | 35 – 45 mm HG |
pH | 7.35 – 7.45 |
Oxygen saturation (SaO2) | 94 - 100% |
Bicarbonate (HCO3): | 22 – 26 mEq/liter |
Abnormal results may indicate respiratory, metabolic, or kidney problems or disease. If you have recently had a head or neck injury, the results are likely to be abnormal.
Call Your Doctor If Any of the Following Occurs
- Signs of infection, including fever and chills
- Numbness
- Excessive bleeding
- Tingling
- Bruising
SOURCE:
American Association for Respiratory Care
Last reviewed June 2001 by Medical Review Board
