Etiologia, Patogenia e epidemiologia de infecções de sítio cirurgico em artroplastias primárias de prótese de quadril e joelho em um hospital universitário

Abstract

The objective was to evaluate the epidemiological indicators, etiopathogenesis for acquisition of infection in the surgical center, in the ward, surgical site of hip and knee arthroplasty in a university hospital in Minas Gerais. The study was a cohort study of patients submitted to hip and knee arthroplasties hospitalized at the Orthopedic and Traumatology Clinic of the Hospital de Clinicas - Federal University of Uberlândia, from May 2006 to December 2011, with active surveillance of the graduates until December 2013. Three surveillance systems were used: National Healthcare Safety Network, laboratorial and graduates. Samples identification and antimicrobial resistance were submitted to clonal discrimination by the Pulsed Field Gel Electrophoresis technique. The project approved by the Research Ethics Committee nr. 424/09. We analyzed 1863 arthroplasties with a 12.6% infection rate, 1275 (68.4%) hip and 14.3% infection and 588 (31.6%) knee with 9.5% infection. The microbiological diagnosis in 80.0% of infection episodes, with acute infections in 51.0%, incisional 61.2% and organ / space infections, in hip arthroplasties were 40.3% and knee 32.1% %. The Late infections were 31.3% and 21.4%, respectively. The etiology of infections highlights S. aureus in 71.2% of infections; while S. aureus (100.0%), Bacilos Gran Negativo (27.6%) with P. aeruginosa present in infections in two arthroplasties, Enterobacter spp. and E. coli in hip and Proteus spp. in the knee. There were predictors of hip infections: malnutrition, neoplasia, more than two comorbidities, risk index of infection surgical site nr 2, and blood and knee transfusion: malnutrition, neoplasia and more than two comorbidities. The microbial contamination in the operating room was elevated with 223 UFC / m3, and the most frequent microorganisms were: Staphylococcus spp. (50.7%) and with S. aureus in 11.4%. The nasal colonization by S. aureus among the members of the surgical team were similar and high (50.0%) among physicians and nursing, while in nursing it was higher in nursing (71.4%), while the contamination of the hands in the latter professionals was 74.6% by epidemiologically important microorganisms, with S. aureus (74.2%) and MRSA phenotype representing 36.8% of the total. The presence of 07 strains of S. aureus in the different sites (clinical specimens, air, nasal mucosa and hands), with predominance of two, one susceptible (A-38.9%) and one resistant to methicillin/oxacillin (B-53.3%). The investigation revealed the seriousness of the problem of hospital-acquired infections in hip and knee arthroplasties, as confirmed by the high epidemiological indicators, as well as the favorable conditions for acquisition of infections in the surgical center and in the ward.