Gentamicin and tobramycin penetration into burn eschar. Pharmacokinetics and microbiological effects
R. E. Polk, C. G. Mayhall, J. Smith, G. Hall, B. J. Kline, E. Swensson and B. W. Haynes
This study was designed to determine whether intravenously administered
gentamicin sulfate and tobramycin sulfate penetrate into the eschar of
patients with severe burns. In addition, each antibiotic's pharmacokinetics
in serum and the effect on eschar microbiology were determined. Twenty
patients with suspected burn wound sepsis received either gentamicin or
tobramycin. The microbiology of the baseline eschar was determined and
repeated on days 2, 4, and 7. All patients had measurable aminoglycoside
tissue concentrations, and elimination from serum was not unusually rapid.
Thirteen patients had baseline eschar cultures positive for Pseudomonas
aeruginosa or Serratia marcescens; eight patients were initially
bacteremic. Pseudomonas aeruginosa strains were sensitive to both
antibiotics and usually declined in concentration with time or were
eliminated; the more drug-resistant isolates of S marcescens persisted or
caused super-infection and bacteremia. Aminoglycoside antibiotics penetrate
into burn eschar and appear to have a substantial effect on eschar
microbiology.
