What Is Blood Gas Analysis?

Arterial blood gas analysis is a lab test that measures how much oxygen is carried in your blood. Blood is collected from an artery, rather than a vein as in regular blood collection, as newly oxygenated arterial blood allows for more accurate readings of gas levels.

Acid or Alkaline

• Arterial blood gas tests measure the pH, or how acidic or alkaline your blood is. Normal adult range is slightly alkaline, between 7.35 and 7.45.

Bicarbonate Levels

• Bicarbonate (HCO3) levels give the heath care provider levels of the chemical buffer, bicarbonate, which keeps the blood at its normal, slightly alkaline level.

Significance

• These pH levels are important to check in people who have liver or kidney disease, or after severe infections which can alter the delicate acid-alkaline balance.

Benefits

• Arterial blood gas tests are done to diagnose and control breathing diseases, such as asthma or chronic obstructive pulmonary disease (COPD). If you are receiving oxygen via ventilation devices, an arterial blood gas test will determine if you are receiving the correct levels of oxygen.

Partial Oxygen Pressure

• The partial oxygen pressure, or PAO2, dissolved in the blood is measured in arterial gas readings. This range can vary depending on your age and the altitude of where you live. PAO2 readings tell the health care provider how well your lungs take in oxygen and how easily it passes into your blood.

Partial Carbon Dioxide Pressure

• Partial Carbon Dioxide pressure, PaCO2, measures the carbon dioxide in the blood. This measurement is also affected by altitude. PACO2 levels determine how well you breathe out, or eliminate, carbon dioxide after your body uses oxygen.