Test Name: Tobramycin
Health Link Test Code: HCTOBR
LIS Test Code: TOBR
CPT Code(s): 80200
Methodology: Particle Enhanced Turbidometric Inhibition Immunoassay (PETINIA)
Days Performed: Daily, 24 hours.
In-Lab Turnaround Time: 4 hours.
Stat In-Lab Turnaround Time: 1 hour.
Collection Container: Red top
Also Acceptable: Green top (with lithium heparin anticoagulant)
Collect specimen for peak level 30 minutes after the end of a 30 or 60 minute infusion. Collect specimen for trough level 15 - 30 minutes prior to start of infusion.
Collection Volume: 2 mL
Pediatric Collection Volume: 0.4 mL
Sample Analyzed: Serum and plasma
Testing Volume: 1 mL
Pediatric Testing Volume: 0.2 mL
Centrifuge immediately. Transfer cell-free serum or plasma to plastic vial. Freeze.
Transport specimen to UWHC Hospital Laboratory within 30 minutes. Transport frozen serum on dry ice if coming from clinic location.
Specimens collected in red cap with yellow ring (SST) or green cap with yellow ring (PST) tubes are not acceptable. Specimens greater than 2 hours old, uncentrifuged when received by the laboratory, are not acceptable.
Optimal therapeutic range:
Peak: 5.0-10.0 ug/mL
Trough: less than 2.0 ug/mL
Interpretation Type: Interpretive Guidelines
Patient samples which contain amikacin, Kanamycin A, Kanamycin B, 3',4' dideoxykanamycin B will yield falsely elevated values for Tobramycin.
Critical Calls: yes
Result of "BELOW" indicates that the result is below the method detection limit of 0.2 ug/mL. Tobramycin is an aminoglycoside antibiotic whose in-vitro activity is similar to that of gentamicin against gram-negative bacteria: it is more active than gentamicin against Pseudomonas aeruginosa. It also has activity against staphylococci.