Test Code Billings Clinic: 4354 Tobramycin, Trough, Plasma or Serum

Performing Laboratory

Billings Clinic Laboratory: Chemistry

Useful For

Monitoring adequacy of serum concentration during tobramycin therapy

Methodology

Particle-enhance turbidimetric inhibition immunoassay (PETINIA)

Specimen Requirements

Submit only 1 of the following specimens:

Serum or plasma should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection.

Plasma

Draw blood in a green-top (lithium heparin) tube(s).
Spin down and send 1.0 mL of heparinized plasma frozen.
Plasma for a trough level is usually drawn just prior to next dose.
Date and time of last dose are required on request form for processing.

Serum

Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
Spin down and send 1.0 mL of serum frozen
Plasma for a trough level is usually drawn just prior to next dose.
Date and time of last dose are required on request form for processing.

Storage/Stability

Specimen Type	Temperature	Time
Plasma, Serum	Refrigerated	3 days
	Frozen (preferred)	1 month
	Ambient	8 hours

Reject Due To

Specimens stored at room temperature > 8 hours
Hemolysis

Reference Values

Therapeutic concentration: 0.0 - 0.9 µg/mL

Call-back toxic concentration value: ≥1.0 µg/mL

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

80200 - Tobramycin

LOINC Code Information

Reporting Name	LOINC Code
Tobramycin, Trough	4059-2
Tobra Dose Date/Time	45285-4