Wound infection rates after intraincisional plus systemic antibiotic prophylaxis in an animal model

The effect of intraincisional application of antibiotics in addition to systemic antibiotic prophylaxis was evaluated in a randomized blind study using a guinea pig model of surgical wound infection. Wounds were contaminated with 10(7) Escherichia coli plus 10(8) Bacteroides fragilis. Wound infection was defined as accumulation of pus draining spontaneously or after opening the wound. Systemic antibiotic prophylaxis with gentamicin plus clindamycin significantly reduced the wound sepsis rate from 83% in the control group to 20% in the treated group (p less than 0.001). Intraincisional application of antibiotics in addition to systemic prophylaxis did not further reduce the rate of wound sepsis (p greater than 0.8).