CARBON DIOXIDE

Code
400.1700
Name
CARBON DIOXIDE
Category
None
Department
Chemistry
Start Date
Expiration Date
Synonyms
CO2
CPT Codes
82374
Site
Main Lab
Reference Test
ATLAS Test Code

CO2

Specimen Information

Type

Gold, SST

Volume

1.0 ml

Transport Info

Room Temperature 7 day stability Refrigerated 7 day stability Frozen stable

Fasting Required?
False
Patient Instructions

Reference Range

21-31 mmol/L

Methodology

Ion-selective Electrode (ISE)

Clinical Significance

Evaluate the total carbonate buffering system in the body, an influence of kidney and respiratory (lung) function. Serum (plasma) carbon dioxide (CO2) is actually a measurement of bicarbonate (HCO3-). This is because the procedure used to measure bicarbonate, first converts it to CO2. In the body, 95% of the CO2 is present as bicarbonate so most of what is measured represents bicarbonate. The kidneys are the organ primarily responsible for maintaining the normal levels of bicarbonate. Metabolic acidosis (pH less than 7.35 and bicarbonate less than 20 mEq/L) is a symptom of renal disease. However, bicarbonate levels are also decreased in the presence of organic acids, (ketone bodies in diabetic ketoacidosis) because bicarbonate is used to neutralize the acids.• Decreased levels of bicarbonate may indicate: - Ketoacidosis - Lactic Acidosis - Kidney Disease - Diarrhea - Methanol poisoning - Salicylate toxicity (such as aspirin overdose) - Ethylene Glycol poisoning - Addison’s Disease (adrenal gland insufficiency)- Treatment with corticosteroids- Excessive use of antacids• Increased levels of bicarbonate may indicate: - Excessive vomiting - Respiratory Dysfunction (breathing disorders) - Hyperaldosteronism - Cushing’s Syndrome• Additional conditions under which the test may be performed: - Alkalosis - Delirium - Dementia - Renal Tubular Acidosis; Distal - Renal Tubular Acidosis; Proximal - Any medical condition in which the examiner feels there might be a metabolic derangement.

Back