Am. Parr et al., Antimicrobial activity of lidocaine against bacteria associated with nosocomial wound infection, ANN PL SURG, 43(3), 1999, pp. 239-245
The authors characterized the in vitro antibacterial properties of clinical
doses of lidocaine on isolates of a variety of bacterial pathogens commonl
y encountered in the setting of nosocomial wound infection (Enterococcus fa
ecalis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus
) as well as a number of resistant strains of methicillin-resistant S. aure
us and vancomycin-resistant enterococci. Time-kill studies were carried out
on bacteria exposed to various clinical concentrations of lidocaine (0%, 1
%, 2%, and 4%) with and without epinephrine (1:100,000). Minimum inhibitory
concentrations and minimum bactericidal concentrations were determined for
some strains using a broth macrodilution method recommended by the Nationa
l Committee of Clinical Laboratory Standards. Lidocaine demonstrated a dose
-dependent inhibition of growth for all strains of bacteria tested. The gre
atest sensitivity to lidocaine was shown by gram-negative organisms; the le
ast sensitive was S. aureus, The addition of epinephrine to the local anest
hetic had no effect on the susceptibility of the bacteria to lidocaine. The
se observations suggest that the surgical benefit of local anesthesia may e
xtend beyond its analgesic properties and may have a role in the prophylaxi
s and, in the case of methicillin- and vancomycin-resistant bacteria, the t
reatment of surgical wound infection, mandating a wider application of this
modality.