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HelpTest Code LAB4589 Gentamicin, Pre-Dose, Plasma or Serum
Additional Codes
| Test Name in EPIC | EPIC Test Code | Mnemonic |
|---|---|---|
| GENT PRE-DOSE | LAB4589 | GENTT |
Methodology
Particle-Enhanced Turbidimetric Inhibition Immunoassay (PETINIA)
Clinical Information
Gentamicin is used in the treatment of serious infections involving aminoglycoside-sensitive organisms.
Monitoring gentamicin concentration in serum or plasma, along with careful clinical assessment, is the most effective means of ensuring adequate therapy. Gentamicin concentration correlates better with antibacterial activity than dosage. A standard dose of gentamicin does not always yield a predictable concentration because the drug’s concentration also depends on the patient’s volume of distribution and on the drug elimination. These factors are influenced by the mode of administration, the volume of extracellular fluid, renal retention, and physiological changes during therapy. Gentamicin has a narrow range of safe and effective concentration. Exposure to high concentrations for a prolonged period may cause renal impairment or ototoxicity. Patients with impaired renal function should be monitored closely while on gentamicin therapy because nephrotoxicity caused by gentamicin may be difficult to distinguish from symptoms of underlying renal disease.
Specimen Requirements
Specimen must be refrigerated until test is performed.
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Plasma
Container/Tube: Light-green top (lithium heparin gel)
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL/pediatric: 0.2 mL in a green-top MICROTAINER
Collection Instructions:
1. Trough specimen should be drawn 30 minutes prior to dose.
2. Spin down, separate from cells and aliquot within 2 hours of draw.
3. Avoid repeated freeze/thaw cycles.
Additional Information:
1. Specimen should be analyzed in an appropriate period of time to assess dosing.
2. Label specimen appropriately (plasma).
Alternate:
Specimen Type: Serum
Container/Tube: Serum gel
Specimen Volume: 1 mL
Specimen Minimum Volume: 0.5 mL/pediatric: 0.2 mL in a red-top MICROTAINER
Collection Instructions:
1. Trough specimen should be drawn 30 minutes prior to dose.
2. Spin down, separate from cells and aliquot within 2 hours of draw.
3. Avoid repeated freeze/thaw cycles.
Additional Information:
1. Specimen should be analyzed in an appropriate period of time to assess dosing.
2. Label specimen appropriately (serum).
Specimen Transport Temperature
Refrigerate 5 days/Ambient 8 hours OK/Frozen OK
Day(s) Test Set Up
Monday through Sunday
Performing Laboratory
Chemistry-
St. Joseph's Medical Center Lab
SMDC Clinical Lab
Fargo Hospital Lab
Test Classification and CPT Coding
80170
Reference Values
0.5-2.0 ug/mL
Useful For/Utiility
Gentamicin assay is used for the quantitative determination of gentamicin in human serum or plasma. The results obtained are used in the diagnosis and treatment of gentamicin overdose and in monitoring levels of gentamicin to help ensure appropriate therapy.