Infecções ortopédicas em pacientes submetidos a artroplastias total de quadril e joelho, hemiartroplastias e osteossínteses: incidência, fatores de risco e influência do ar do Centro Cirúrgico em um Hospital Universitário Brasileiro

Abstract

The purpose of this study was to evaluate the air contamination during total hip arthroplasty, total knee artroplasty, hemiarthroplasty, and osteosyntesis and the incidence of orthopedic risk factors in primary surgeries in case versus control. The air microbiological assessments were: seven of total hip arthroplasty and total knee arthroplasty, three of hemiarthroplasty, and seven of osteoyintesis, with petri exposure of one hour, in the beginning and the end of the surgery. The number of people and door openings during the surgery were evaluated. The microorganisms were identified and isolated by classical phenotipical tests. The figures were construed according to Agência Nacional de Vigilância Sanitária (ANVISA)/Brazil. The study was from May 2006 until June 2007, through surgical component National Nosocomial Infections Surveillance (NNIS) with regular visits to the hospital and individual questionnaires with clinical and demographic data, and orthopedic infection definitions according to Centers Disease Control and Prevention (CDC). The dirty/infected surgeries and revisions were ruled out. The air microbiological monitoring showed the following: numbers over recommended in the hemiarthroplasties (36.9 UFC/m³), in the beginning of the surgery; hip and knee total arthroplasty four surgeries with ultra clean rooms with numbers over the recommended (>50 UFC/m³) and three rooms with conventional air in the end of the surgeries (216 UFC/m³). The contamination was mainly from Gram positive cocos (71.4%), with the Staphylococcus (86.9%), being coagulase-negative Staphylococcus (62.7%) and S. aureus (37.3%); the presence of fungus (21.2%) particularly in the conventional air. It was noticed in all surgeries a high number of people in the rooms (X> 9) and door openings (X> 60 times). There was no difference (p> 0.05) among the microorganisms numbers. In the total the surveillance was performed in 53 total hip arthroplasties, and 12 in the knee, 14 hemiarthroplasties, and 584 osteosyntesis, with orthopedic infection rate of 17.0%, 25.0%, 28.6%, and 11.4% respectively. Around 78.0% (457/584) of the osteosyntesis were considered clean surgeries, with an infection rate of 7.5% (32/425). The risk factor associated with the surgeries (p< 0.05) were: for total hip arthroplasty: time &#8805; 15 days and pos-operation &#8805; 4 days of hospital, nephropathy, cardiopathy, mechanical vent (VM) and central vascular catheter (CVC); in the hemiarthroplasties: pos operation time >4 days and NNIS Risk Index 2 and; in the osteosintesis: time &#8805; 15 days and pre-operation &#8805; 7 days in the hospital, traffic accidents (automobile and motorcycle), falls, bad nutrition, invasive procedures (VM and vesical probe), NNIS Risk Index 2, exposed fractures, politraumas, pathological fractures, external fixation, and osteotomy. The infections were considered in most of the cases as incisional (78.6%), but almost all of the organ /space infections were observed in the osteosyntesis. The levels of the air contamination in the conventional and ultra clean rooms in the orthopedic surgery rooms are above the recommended numbers, representing a potential risk of orthopedic hospital infections. The frequency of orthopedic infections was high in the four groups and was associated with risk factors. The clinical isolated ones showed frequent high resistance to antibiotics, including cefazolin, which is used as prophylaxy. The length of hospital internations were long and more significant in the total hip arthroplasties and infected osteosyntesis than in the non-infected control group, which associated with the antibioticotherapy, tests, and surgical revisions have a great impact in the costs.