Antibiotic Prophylaxis in Oncological Surgery of Breast

KIND OF STUDY: Primary, clinical, prospective, randomized, two-parallel-group, double-blind, controlled, interventional, analytical. SAMPLE CALCULATION: based on proportions observed in a previous study with and without antibiotic use in breast surgery (VEIGA-Filho, 2010) the number calculated patients per group was 62, with a significance level of 5% and power 80% of the test. SELECTION: will be selected in Mastology outpatient clinics 124 female patients to be undergoing breast surgery for malignancy. The selection of patients will be divided in two groups PLACEBO (N = 62): receive 0.9% saline 100 ml intravenously and CEFAZOLIN GROUP (N = 62): receive 2 g of cefazolin diluted in 0.9% saline by endovenous. In both groups will be passed in a standardized manner, a sterile swab soaked in saline over a standard 5cm by 10cm area determined by a field fenestrated sterile filter paper. Preoperatively will default collection in the region higher interquadrantes breast to be operated immediately above areolopapilar complex, which is not included in the designated area for collection. At end surgery and also in the first postoperative day, the sterile field will be positioned with fenestration on the wound. Tha material will be Standard microbiological methods used to identify microoganismos. 0.2 ml aliquots of each sample are plated on agar media hypertonic mannitol, selective for Staphylococcus sp, Sabouraud agar with chloramphenicol (0.05mg / ml), selective for fungi, agar EMB Teague, selective for enterobacteria, and agar blood, for the presence of hemolytic colonies. After 48 hours, the reading of the number of colony forming units will be held by a microbiologist. Patients are regularly monitored for the occurrence of infection, once a week for the first 30 days by a single surgeon. They will be used and the definitions of surgical site infection classifications adopted by CDC