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Test Code
NH4
Test Name
Ammonia
CPT Codes
82140
Expected Turnaround Time
1 day
Clinical Utility

Used in the evaluation of hepatic coma and comas of unknown origin, neurological deterioration, urea cycle disorders, hepatic disease, encephalopathy, and Reye’s syndrome.
Specimen and Container Info

Specimen Type: Plasma

Collection Container: Lavender Top (EDTA)

Minimum Acceptable Volume: 0.4 mL

Volume reflects estimated whole blood.

Note: This volume does not allow for repeat testing.
Processing and Submission Instructions

**Note: Specimen must be processed within 15 minutes of collection.

  1. Centrifuge specimen
  2. Transfer plasma to plastic aliquot tube and freeze.
  3. Once frozen, transport specimen submerged in dry ice.

Tubes with anticoagulant: To ensure accurate test results, all tubes containing an anticoagulant or preservative must be allowed to fill completely. Attempts to force more blood into the tube by exerting pressure, as in collection with a syringe, will result in damage to the red cells (hemolysis).
Transport Instructions
  • Transport on ice to the laboratory within 15 minutes of collection.
  • If collection to receipt in laboratory is more than 15 minutes see Processing and Submission Instructions.
Stability Requirements

Refrigerated

15 minutes - unprocessed

3 hours - after processing

Frozen

7 days
Methodology
Enzymatic
Reference Intervals

HNL Lab Medicine Chemistry Reference Intervals
Critical Values

HNL Lab Medicine Critical Values
Performing Location
Carbon Hospital, Cedar Crest Hospital, Dickson City Hospital, Hazleton Hospital, Hecktown Oaks Hospital, Muhlenberg Hospital, Pocono Hospital, Redeemer Health, Schuylkill Hospital
Testing Schedule
Routine daily, STAT testing available
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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