Ammonia

Message

Performed in Chemistry

Test Code

AMON

CPT Codes
82140

Preferred Specimen

Lavender Top, EDTA Plasma
LiHep Green Tube (WyMCC)

Other Acceptable Specimens

None

Instructions

Place collected tube immediately on ice and centrifuge, preferably at 2-8 ºC
Test within 30 minutes of venipuncture or freeze separated plasma immediately

Specimen Stability

Room Temperature 30 minutes
Refrigerated 2 hours
Frozen 3 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Plasma prepared with other anitcoagulants
Serum
Outdate/expired tube
Hemolyzed, icteric or lipemic
Contaminated

FDA Status
FDA Approved

Setup Schedule

Daily, Sunday through Saturday

Report Available

Less than 4 hours

Clinical Significance

Ammonia is generated primarily in gastrointestinal tract by metabolism of nitrogenous compounds. An excess of ammonia can be toxic to central nervous system. Krebs-Henseleit urea cycle provides a means of disposal of ammonia by metabolizing ammonia to urea in liver. Hyperammonemia in infants can be caused by inherited deficiencies of urea cycle enzymes or acquired through acute (as in Reye’s syndrome) or chronic (as in cirrhosis) liver disease. In adults, elevated ammonia levels can aid in diagnosis of liver failure or hepatic encephalopathy from advanced liver diseases such as viral hepatitis or cirrhosis.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.