Phenobarbital Drug Level
Label Mnemonic: PHEB
Epic code: LAB30
Order form: Laboratory Requisition
Supply order: Supply Order Form
Billing: Billing Policies
CPT code: 80345
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:
Therapeutic range: 15-40 μg/mL
Toxic concentration > 60 μg/mL
Coma without reflexes may occur at concentrations > 100 μg/mL.
Test Limitations:
Icterus: No significant interference up to an I index of 60 (approximate bilirubin concentration: 60 mg/dL).

Hemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration: 1000 mg/dL).

Lipemia (Intralipid): No significant interference up to an L index of 600 (approximate triglyceride concentration: 1200 mg/dL). There is poor correlation between turbidity and triglycerides concentration.

Rheumatoid factor: No significant interference up to a concentration of 200 IU/mL.

Mephobarbital (greater than 100%) and amobarbital (greater than 20%) show significant cross-reactivity.

As with any assay employing mouse antibodies, the possibility exists for interference by human anti-mouse antibodies (HAMA) in the sample, which could cause falsely elevated results.
Methodology:
Kinetic Interaction of Microparticles in Solution (KIMS)
Sample Processing:
Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells within 1 hour of collection. Send specimen in original tube. Do Not transfer to another tube.
Each sample must be labeled with at least TWO full patient identifiers (First/Last Name & DOB are sufficient for non-UIHC affiliated clients) to avoid sample rejection/delays.
Sample Storage:
Refrigerate.
All sample storage requirements are intended for delivery to UIHC within 24 hours of collection for testing. If samples won't arrive in this time period, please call the UIHC Core Lab for alternative storage/shipping instructions (319-356-3527).
Transport Instructions:
Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place completed requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
80345
 
See Additional Information:
Chemistry Critical Lab Values