The Annals of Thoracic Surgery, Vol 48, 228-231, Copyright © 1989 by The Society of Thoracic Surgeons
Gentamicin solution for mediastinal irrigation: systemic absorption, bactericidal activity, and toxicity
ME Kopel, L Riemersma, DC Finlayson, V Tobia, EL Jones, RI Hall, R Mullins and V Lampasona
Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia.
Local irrigation with gentamicin sulfate represents a possible substitute
for neomycin sulfate, used for many years but now no longer available for
use as an irrigation fluid. In this investigation, mediastinal irrigation
with gentamicin was used in 12 patients who had experienced problems after
a heart operation. The regimen employed for mediastinal irrigation with
gentamicin was equipotent with that using neomycin. We sought to determine
the degree of absorption and risk of either inadequate or toxic blood
levels that might follow gentamicin absorption. Irrigation periods were
short, ranging from one to four days and determined by measurements of
plasma gentamicin concentration using radioimmunoassay evaluation. Systemic
gentamicin absorption occurred in all patients. Toxic levels of higher than
8.0 micrograms/mL occurred and were size related, ie, correlated with
smaller body weight and surface area, and sex related, ie, female sex.
Larger-sized patients often had inadequate levels. Despite the potential
risk from toxic blood levels, major increases in serum creatinine levels
were not seen. These findings suggest that monitoring of plasma gentamicin
levels during mediastinal irrigation with gentamicin is mandatory to avoid
both inadequate treatment and toxicity.
