Arterial Blood Gases, or ABGs, measure the amounts of oxygen, carbon dioxide and acid/base level in the blood, according to Medline Plus, a service of the U.S. National Library of Medicine. ABGs are ordered if the patient has difficulty breathing, symptoms of an acid/base imbalance, or if a pre-existing condition is worsening, and blood is taken from an artery in the wrist, groin, or inside of the elbow.
Respiratory Acidosis
The kidneys and lungs work together to keep a balanced acid/base, or pH, level. Respiratory acidosis is the result of too much carbon dioxide and not enough oxygen in the blood. This condition can be caused by chest injury, chronic lung disease, or overuse of sedatives. ABG results will show a low pH and a high PCO2, according to Lab Tests Online.
Respiratory Alkalosis
Respiratory alkalosis can occur if a patient hyperventilates. Stress, pain, or lung disease may cause this rapid breathing. Hyperventilation will result in too much oxygen in the blood and not enough carbon dioxide. Patients with respiratory alkalosis will have a lower pH and an increased PCO2 on an ABG test.
Metabolic Acidosis
Metabolic acidosis happens when there is too much acid in the blood. Diarrhea, complications from illness such as diabetes and bowel obstruction can cause metabolic acidosis. ABGs of a patient with metabolic acidosis would show lower pH and decreased bicarbonate, or HCO3.
Diabetic Acidosis
Diabetic acidosis happens when there is too much of the acid known as ketones in the body due to diabetes. A diabetic may not have enough insulin to break down blood sugar, so the body uses fat to digest the sugars. Ketones are the byproduct of this alternative process. Blood gases would show a pH lower than 7.4, low bicarbonate levels, and a low PcO2.
Hyperchloremic Acidosis
Hyperchloremic acidosis is caused by too much sodium bicarbonate in the blood. This can occur if a patient experiences large amounts of diarrhea, or if