Acetaminophen
Label Mnemonic: APAP
Epic Lab Code: LAB43
Downtime Form: A-1a Therapeutic Drug Assay Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL; light green top tube or ONE Microtainer®.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
Acetaminophen concentrations greater than 150 μg/mL at four hours after ingestion or greater than 40 μg/mL at 12 hours after ingestion are often associated with toxicity. Critical value: >40 μg/mL
Test Limitations:
Hemolysis: No significant interference up to an H index of 800 (approximate hemoglobin concentration: 800 mg/dL).

Lipemia: No significant interference up to an L index of 400 (approximate triglycerides concentration: 800 mg/dL). Note there is poor correlation between turbidity and triglyceride concentration.

Icterus: Icterus can cause positive interference with the acetaminophen assay. Testing is cancelled with an icteric index of 30 or greater.
Methodology:
Spectrophotometric
CPT Code:
80329
 
See Additional Information:
Chemistry Critical Lab Values