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Test Code Ammon Art Ammonia, Blood Arterial

Important Note

NO MICROTAINERS. Read "Notes" under Sample Requirements before collection.

Place specimen in outside pocket of a pre-filled biohazard bag of ice, then put into biohazard bag for transport.

Clinical System Name

Ammonia, Blood Arterial

Description

Ammonia is a waste product of protein catabolism that is potentially toxic to the central nervous system.  Increased plasma ammonia may be indicitive 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.

Sample Requirements

Specimen:  Whole Blood

Container(s):  Dark Green/Sodium Heparin

Preferred Vol: At least 2.5 mL in an unopened 4.0mL Dark Green/Sodium Heparin

Minimum Vol: 0.5mL in a Heparinized Syringe

Note:  Place specimen in separate bag and then in bag with ice.  For 4.0mL Dark Green/Sodium Heparin tubes, less than 1/2 full will be rejected.  Remove air bubbles from Heparinized Syringe immediately after collection.  A venous sample is preferable unless an arterial line is in place.

Processing Instructions

Reject due to: Insufficient quantity, age of specimen, specimen not transported correctly.

Spin: Yes

Aliquot: Yes. Transfer blood gas syringe contents to a bullet tube; centrifuge for 3 minutes.

Storage location:  Core 5 Refrigerator

Notes:  Method is affected by exposure to red blood cells and hemolysis.  Not affected by icterus or lipemia.

 

Off-site collection:  Note on requisition if sample is venous or arterial.  Place specimen in separate bag and then in bag with ice.  Centrifuge, remove plasma from cells (within 15 minutes), and freeze plasma ASAP.  Keep specimen frozen during transport. Plasma must be removed from red blood cells within 15 minutes for an accurate ammonia result.

Stability

Specimen Type Temperature Time
Whole Blood

Refrigerated

≤ 15 M
Plasma RT

No

Plasma 2-4oC

≤ 3 Hours

Plasma -20o C or -70o C

≤ 24 Hours

 

Plasma must be removed from red blood cells within 15 minutes for an accurate ammonia level.

Availability

STAT Performed TAT
Y 24/7 1 H

 

Performing Laboratory

Seattle Children's Laboratory    

Department

Department:  Core Lab Chemistry

Phone Number: 206-987-2617

 

 

Reference Range

 

Age uMol/L
O - 3 days 9 - 107
3 days - 2 week 9 - 92
2 weeks - 2 months 9 - 50
2 months - adult 9 - 35

 

Ranges are established in venous plasma. Arterial plasma values will be lower.
 

Methodology

Method:  Colorimetric method by Vitros 4600

Minimum Volume: 0.05 mL serum or plasma. 

Analytical Volume:  0.02 mL + 0.03 dead space.

CPT Codes

82140