Ammonia
Order Code: PNH3
Order Form: Laboratory Requisition
Specimen:
Plasma
Collection Medium:
Lavender top tube 4 mL (EDTA)
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL; lavender top (2 mL lavender top for pediatric patients) lavender top must be half full.
Rejection Criteria:
Syringe is not acceptable.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Analytic Time:
1 hour (upon receipt in laboratory)
Reference Range:
7-42 mcmol/l
Test Limitations:
Criterion: recovery within plus or minus 10% of initial values Icterus: No interference up to an I index of 60 (approximate conjugated and unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: No interference up to an H index of 50 (approximate hemoglobin concentration: 50 mg/dL). Lipemia (Intralipid): No interference up to an L index of 170. There is poor correlation between turbidity and triglycerides concentration. Absorbance flagging may also be observed as a result of an absorbance increase.
Methodology:
Enzymatic
Instructions:
Draw sample and place on ice. Specimen should be spun and the plasma aliquotted and frozen as soon as possible after the draw.
Sample Processing:
Centrifuge at 3000 RPM for 10 minutes.
Aliquot plasma into plastic container and cap (glass is not acceptable).
Specimen must be frozen immediately.
Label transport tube with two patient identifiers, date and time of collection.
Sample Storage:
Freeze specimen immediately.
Transport Instructions:
Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in styrofoam container.
CPT Code:
82140