Ammonia

Message

Test performed at York Hospital Laboratory.
For STAT testing, notify the lab prior to collecting the specimen.

Test Code

AMON

CPT Codes
82140

Preferred Specimen

0.2 mL plasma collected in a lithium heparin (green-top) gel separator tube

Instructions

Place sample on ice immediately after collection.
Plasma must be removed from the cellular material within 15 minutes of collection.

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 3 hours
Frozen: 24 hours

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

Hemolyzed specimen
Specimen not received on ice
Specimen with collection time not recorded on the tube
Specimen received after 15 minutes from collection time

Methodology
Colorimetric

Setup Schedule

Daily

Report Available

Next Day
Available STAT 2 hours

Reference Range

9-33 umol/L

Clinical Significance

Ammonia is a waste product of protein catabolism; it is potentially toxic to the central nervous system. Increased plasma ammonia may be indicative of hepatic encephalopathy, hepatic coma in terminal stages of liver cirrhosis, hepatic failure, acute and subacute liver necrosis, and Reye's syndrome. Hyperammonemia may also be found with increasing dietary protein intake.

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.