Although
cefazolin prophylaxis has proven efficacy in
vascular surgery, Staphylococcus aureus
wound infections are still an important postoperative complication. In cardiac surgery,
cefazolin's susceptibility to hydrolysis by staphylococcal
beta-lactamase has been proposed to account for some prophylaxis failures. To determine whether the incidence of vascular
wound infections can be reduced by administering a more
beta-lactamase-stable
cephalosporin, we undertook a prospective, randomized trial of
cefuroxime versus
cefazolin.
Cefuroxime was administered as a 1.5 gm dose before operation and 750 mg every 3 hours during operation.
Cefazolin was given as 1 gm before operation and 500 mg every 4 hours during operation. Both agents were continued every 6 hours after operation for 24 hours. Deep
wound infections developed in seven of 272 (2.6%)
cefuroxime and three of 287 (1.0%)
cefazolin recipients (p = 0.2). Staphylococcus aureus
wound infections occurred in five
cefuroxime versus two
cefazolin recipients. In vitro evaluation of six of the study isolates plus an additional eight S. aureus strains from vascular
wound infections showed greater susceptibility of the strains to
cefazolin than
cefuroxime (median minimal inhibitory concentrations of 0.5 and 2.0 micrograms/ml, respectively, p less than 0.05). Furthermore, despite its more frequent intraoperative redosing,
cefuroxime exhibited lower trough serum concentrations than
cefazolin. Among
cefuroxime recipients,
infection-associated procedures were significantly longer than
infection-free procedures (p less than 0.05), suggesting that low tissue
antibiotic concentrations may have contributed to the pathogenesis of these
infections. In contrast, the length of the procedure was not a risk factor for
infection among
cefazolin recipients.(ABSTRACT TRUNCATED AT 250 WORDS)