Prophylactic use of antibiotics against the pathogens likely to contaminate the procedure is considered beneficial to prevent surgical site infections. We asked that an increase in the effective blood concentration by increasing the administration dose immediately before the operation can decrease the incidence of surgical site infection and performed a prospective study in patients undergoing total hip arthroplasty.
The subjects consisted of 357 patients who underwent initial THA between January 2006 and June 2012. We compared 172 patients who received an initial dose of Unasyn-S 1.5 g (1.5-g group) and 185 treated after January 2010 when the initial dose alone was increased to 3.0 g (3.0-g group) in terms of the incidence and depth (superficial or deep layer) of SSI.
SSI developed in 7 (1.96 %) of all patients, consisting of 5 (2.91 %) in the 1.5-g group and 2 (1.08 %) in the 3.0-g group. Its incidence did not differ between the two groups, but was slightly lower in the 3.0-g group. Deep infection was observed in 2 of the 5 patients in the 1.5-g group but neither of the 2 in the 3.0-g group.
Although there is statistically no significant difference in the incidence of SSI, our data suggest that an increase of the preoperative antibiotics reduces the incidence of SSI and can be an effective measure for the prevention of infection.