Test Code LAB47 Ammonia
Performing Laboratory
Asante Rogue Regional Medical Center / Asante Three Rivers Medical Center / Asante Ashland Community Hospital
Specimen Minimum Volume
200 microliters (0.2 mL) of plasma
Note: If a microtainer is used it must be filled completely which is about 400 microliters of whole blood
Billing Code
3010175
Methodology
L-Glutamate Dehydrogenase
Specimen Requirements
Lithium Heparin Green top tube or Lithium Heparin Microtainer - collected by venipuncture
Plasma, collected with lithium heparin into an evacuated collection tube is required. Ideally, the collection tube should be completely filled with blood and immediately placed on ice. Centrifuge the sample in a refrigerated centrifuge as soon as possible to separate the plasma. Specimen must be centrifuged within 30 minutes.
Day(s) Test Set Up
All samples analyzed STAT
Test Classification and CPT Coding
82140 ASSAY OF AMMONIA
Additional Information
Monitoring blood ammonia levels can be useful in the diagnosis of hepatic encephalopathy and hepatic coma in the terminal stages of liver cirrhosis, hepatic failure, acute and subacute necrosis and Reye’s Syndrome.
Hemolyzed samples should not be used as erythrocytes contain levels of ammonia approximately 3 times that of plasma. Do not keep tourniquet on for a prolonged time. Do not have patient clench or squeeze their fist during collection. Do not allow the sample to be exposed to room air prior to analysis. Lithium heparin microtainer accepted if pediatric sample is collected via venipuncture and the microtainer kept on ice and received within 30 minutes of collection.
Performing Department
Chemistry
Reasons for Rejection
Specimen not on wet ice
Hemolyzed Specimen
Specimen not centrifuged within 30 minutes
Specimen exceeded time limit
Quantity not sufficient (QNS)
Lack of Two Patient Identifiers:
1-Patient's First & Last name
2-Patient's Date of Birth
Specimen Transport Temperature and Stability
Separate plasma immediately and keep on wet ice
Not stable at room temperature.
Stable for 3 hours if kept at 2-4°C once centrifuged.
Send to laboratory immediately