[Effect of a short antimicrobial prophylaxis regimen on the prevalence of postoperative infection in elective orthopedics and traumatology surgery].

Objective: To assess the efficacy of two antimicrobial prophylaxis regimens, a short cycle and the standard one, on the prevalence of acute postoperative infection in orthopedic surgery for acute and chronic disease of a thoracic and a pelvic limb.

Material And Methods: Prospective, observational, experimental randomized, double-blind trial in patients undergoing orthopedic surgery due to acute or chronic disease, between April and September 2009. The sample size was determined using the formula to calculate the finite population. Two groups were formed: one was given cefalotin for 24 hours plus ten additional days of dicloxacillin, the standard regimen and a second one that received cefalotin for 24 hours and placebo for ten days. The wound was assessed during hospitalization and it was checked on days 5, 8, 14 and 30. A statistical software was used for the statistical analysis, which included Student's t-test and chi2, and descriptive statistics for percentages, frequencies, means and standard deviations. The protocol was approved by the local health research committee.

Results: One hundred and thirty-one patients were included. Group I included 62 patients with cefalotin/dicloxacillin and Group II 69 patients with cafalotin/placebo for 10 days. In Group I one patient had infection and in Group II there were 3 cases, with p = 0.50 when chi2 was applied.

Conclusions: Antimicrobial prophylaxis with 24 hour-cefalotin has the same effect on the prevalence of postoperative infection than a prolonged cycle of cefalotin plus dicloxacillin, according to the chi2 test. It is clear that there is no considerable benefit in giving antibiotics indiscriminately and for long periods of time compared with protection from infection in clean wounds.