Pentobarbital Level (Sendout)

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General Information

Lab Name
Pentobarbital Level (Sendout)
Lab Code
RPENTS
Epic Name
Pentobarbital Level (Sendout)
External Test Id
PENTS
Description

Useful For: Monitoring of pentobarbital therapy treatment.

    Collection Timing: Draw blood immediately before next scheduled dose.

    References
    Synonyms
    Nembutal, PENTOG, PENTS
    Components
    Code Name
    RPENTR Pentobarbital Level

    Interpretation

    Method

    Gas Chromatography Mass Spectrometry (GC-MS)

    Reference Range
    See individual components
    Ref. Range Notes

    Reference Values:

    Therapeutic Ranges:

    Hypnotic: 1.0-5.0 mcg/mL
    Therapeutic coma: 20-50 mcg/mL
    Reducing intracranial pressure: 30-40 mcg/mL*

    *This degree of sedation requires artificial respiratory support.

      Toxic Concentration: >10 mcg/mL

        Cutoff concentrations by gas chromatography mass spectrometry: 0.5 ng/mL

          Interpretation: Pentobarbital concentrations above 10 mcg/mL have been associated with toxicity. Therapeutic concentrations when used as a hypnotic are 1 to 5 mcg/mL, while concentrations between 20 and 50 mcg/mL are used for therapeutic pentobarbital coma to help control intracranial pressure.

          Interferences and Limitations

          Cautions:

          • The concentration at which toxicity occurs varies and results should be interpreted in light of clinical situation.
          • Specimens collected in serum gel tubes are not acceptable because the drug can absorb on the gel and lead to falsely decreased concentrations.
          References

          Ordering & Collection

          Specimen Type
          Blood
          Collection

          6 mL blood in RED TOP tube

          • Unacceptable: Serum gel/GOLD SST.

          Collection Timing: Draw blood immediately before next scheduled dose.

          Handling Instructions

          Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial within two hours of collection. Refrigerate serum while awaiting shipment. Transport with a cold pack.

          • Note: Specimens collected in serum gel tubes are not acceptable because the drug can absorb on the gel and lead to falsely decreased concentrations.

          Stability: Refrigerated (preferred): 28 days; Frozen: 28 days; Ambient: 28 days.

          Reject Due To: Gross hemolysis or serum from a gel tube. Gross lipemia and gross icterus are acceptable.

          Quantity
          Requested: 2 mL serum
          Minimum: 0.7 mL serum

          Processing

          Receiving Instructions

          Centrifuge sample and transfer serum to a separate plastic vial within two hours of collection. Refrigerate serum.

          Sendouts:

          • Order Mayo Test: PENTS
          • Interfaced: Yes [Interface: 601; Worksheet: MARF]

          Stability: Refrigerated (preferred): 28 days; Frozen: 28 days; Ambient: 28 days.

          Reject Due To: Gross hemolysis or serum from a gel tube. Gross lipemia and gross icterus are acceptable.

          Misc Sendout

          Performance

          Lab Department
          Sendouts Mayo Lab (RF)(MARF)
          Frequency
          Performed: Thursday. Reported: 3-9 days from sample receipt at Mayo Clinic Laboratories.
          Available STAT?
          No
          Performing Location(s)
          Sendout Mayo Clinic Laboratories (Superior Drive)
          800-533-1710

          3050 Superior Drive NW
          Rochester, MN 55901

          Billing & Coding

          CPT Codes
          80299
          LOINC
          3924-8
          Interfaced Order Code
          UOW5453