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Specimen Collection Manual and Test Catalog

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AMMONIA

Geisinger Epic Procedure Code:  LAB1732    Geisinger Epic ID:  6457

SPECIMEN COLLECTION
Specimen type: 

Plasma


Preferred collection container: 
Specimen required: 

1 mL aliquot plasma; minimum 0.5 mL


Special notes: 

Mix well. Place specimen immediately into an ice slurry. See Processing Instructions below. Microcollection device should only be used for patients under 2 years old.



SPECIMEN PROCESSING
Processing instructions: 

Centrifuge (cold if possible) to separate plasma. Place specimen on ice and assay immediately. Exposure to air should be minimized. For off-campus laboratory, separate plasma immediately upon centrifugation. Freeze plasma at -20°C (-70°C is acceptable).


Transport temperature: 

Refrigerated or frozen.


Specimen stability: 

Refrigerated: 2 hours. Frozen: 3 days.


Rejection criteria: 

Hemolyzed specimens are not acceptable.



TEST DETAILS
Reference interval: 

Ammonia (umol/L)
0 to 14 days: 56-107 
15 days to < 2 years: 40-80 
2 years and above: 11-35


Critical values/courtesy alerts: 
Above 80 umol/L
CPT code(s):  82140
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Test includes: 

Ammonia.


Methodology: 
Enzymatic method with glutamate dehydrogenase
Synonyms: 

NH3, AMON


Clinical significance: 

Elevated blood ammonia levels have been associated with severe liver dysfunction such as hepatic encephalopathy, coma resulting from cirrhosis, severe hepatitis, Reye's syndrome, and drug hepatotoxicity. Also, elevated ammonia has been reported in cardiac failure, azotemia, and pulmonary emphysema.


Doctoral Director(s): 
Hoi-Ying Elsie Yu, PhD, DABCC, FADLM
Sheng-Ying (Margaret) Lo, PhD, DABCC
Review Date:  01/06/2025

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