Test Code AMON Ammonia Level

Important Note

Specimens need to be placed on ice immediately after collection.
Capillary collected specimens are not acceptable.
Plasma from the specimen needs to be separated from cells and aliquoted within 15 minutes of collection.

Additional Codes

Cerner	NextGen
Ammonia Level	Ammonia Level

Alternate Name(s)

NH3

Useful For

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.

Methodology

Colorimetric (reflectance spectrophotometry)

Patient Preparation

None

Collection Instructions

Patient should NOT clench fist during collection, as muscular exertion may increase venous ammonia levels.
Specimens need to be placed on ice immediately after collection.
Capillary collected specimens are not acceptable.
Plasma from the specimen needs to be separated from cells and aliquoted within 15 minutes of collection.

Specimen Requirements

Container

Specimen Type	Tube
Lithium Heparin Plasma

Stability

Plasma from the specimen needs to be separated from cells and aliquoted within 15 minutes of collection.

Storage	Temperature	Stability
Room Temperature	18-28°C	Not recommended
Refrigerated	2-8°C	≤ 3 hours If separated within 15 min.
Frozen	≤-18 °C	≤ 24 hours If separated within 15 min.

Rejection Criteria

Specimens not received on ice.
Specimens where plasma has not been separated from cells and aliquoted within 15 minutes of collections.
Gross Hemolysis.

Result Reporting and Reference Values

Reported in µmol/L.

Age	Low	High	Critical Low	Critical High
0-3 d	64	107	N/A	>108
3 d – 14 d	56	92	N/A	>100
14 d – 2 mo	21	50	N/A	>100
2 mo – 18 Y	9	33	N/A	>100
18 Y– 150 Y	9	30	N/A	>100

Reflex Testing