Peritoneal fluid concentrations of cefoxitin in children during appendectomy

Fifteen children underwent appendectomy following administration of a single i.v. dose of cefoxitin (20 mg/kg). The mean cefoxitin concentration of peritoneal fluid prior to resection of the appendix was 9.3 ± 2.9 g/ml, representing 264% ± 47% of the concurrent serum concentration. All samples of appendiceal tissue contained less than 5.0 g/g. Peritoneal cefoxitin levels exceeded the usual minimal inhibitory concentration of Staphylococcus aureus and Escherichia coli, but were indadequate for Bacteroides fragilis. We recommend use of a higher cefoxitin dose (40 mg/kg) for the preoperative prophylaxis of appendectomy in children.