Levels are performed on 5-10ml of clotted blood in the laboratory and results are available on the ward computer. Abnormal results are telephoned to the requesting doctor.
It is the responsibility of the requesting clinician to look up the assay results and modify the dosing if necessary. Advice on dosing is always available from the Consultant Microbiologist.
Unless advised by the microbiologist doses of gentamicin or vancomycin should not be delayed pending results of tests for levels.
Gentamicin levels
Once daily gentamicin
A trough level only is required, taken immediately before the 2nd dose, and repeated every 3-4 days thereafter. The level should be less than 1mg/l
Multiple daily dosing of gentamicin
Trough and peak levels are required, starting around the 3rd to 5th dose and repeated every 3-4 days thereafter. Trough levels are taken immediately before a dose and peak levels 1 hour after the dose.
Trough level should be less than 2mg/l. Peak level should be between 5 and10mg/l.
Vancomycin levels
Trough and peak levels are required starting around the 3rd to 5th dose and repeated every 3-4 days thereafter. Trough levels are taken immediately before a dose and peak levels 2 hours after the infusion has finished
Trough level should be less than 10mg/l. Peak level should be between 18 and 26mg/l.
Dosing adjustments or more frequent testing levels may be recommended by the microbiologist.
Take care to label "trough" or "peak" as appropriate on sample. Please state dose, time of dose and time blood was taken on request form.
