Preditores de mediastinite em cirurgia cardíaca Predictors of mediastinitis after cardiac surgery

Abstract

INTRODUÇÃO: A mediastinite é uma grave complicação da cirurgia cardíaca, com incidência de 0,4% a 5%, mortalidade de 10% a 47% e elevada morbidade. OBJETIVO: Identificar os fatores de risco pré e transoperatórios para mediastinite após a cirurgia cardíaca em nosso hospital. MÉTODO: Estudo prospectivo de 1298 pacientes submetidos à cirurgia cardíaca no Hospital São Lucas no período de março de 1997 a maio de 2000. Foram avaliados nove potenciais fatores de risco associados a mediastinite (obesidade, diabetes mellitus, doença pulmonar obstrutiva crônica, ponte mamária, tempo de bypass cardiopulmonar, tabagismo, sexo, fração de ejeção e cirurgia cardíaca prévia), através de análise univariada, seguida de análise multivariada de regressão logística. RESULTADOS: Dos 1298 pacientes estudados, 62,6% eram homens e 18,3% eram diabéticos. Trinta e oito (2,9%) pacientes apresentaram mediastinite e seis (15,8%) destes morreram. Quatro variáveis foram selecionadas por análise univariada (pOBJECTIVE: Mediastinitis is a serious complication of open-heart surgery, with an incidence that varies from 0.4% to 5%, mortality from 10% to 47% and a high morbidity rate. OBJECTIVE: To identify preoperative and trans-operative risk factors of mediastinitis after open-heart surgery in our hospital. METHOD: This was a prospective study of 1298 patients submitted to the open-heart surgery in São Lucas hospital in the period from March 1997 to May 2000. Nine potential risk factors associated with mediastinitis were studied (obesity, diabetes mellitus, chronic obstructive pulmonary disease -COPD-, internal mammary artery, cardiopulmonary bypass time, smoking, gender, ejection fraction and previous heart surgery) using univariate analysis, where necessary followed by multivariate logistic regression. RESULTS: Of the 1298 studied patients, 62.6% were men and 18.3 suffered from diabetes. Thirty-eight patients (2.9%) presented with mediastinitis postoperatively, and six (15.8%) of these died. Four variables identified as risk factors by univariate analysis (p<0.05) and were after analysed by logistic regression. Three variables were identified as independent predictors of mediastinitis: obesity (p=0.008), COPD (p=0.007) and diabetes mellitus (p= 0.009), even when gender and age were analysed. The internal mammary artery graft was observed as risk predictor only when associated to the obesity. CONCLUSION: In our hospital, mediastinitis occurs most frequently in patients suffering from obesity, diabetes, and/or COPD and in the obese patients in which internal mammary artery was used.

Keywords

• Mediastinite
• Infecção mediastinal
• Cirurgia cardíaca
• Infecção cirúrgica
• Mediastinitis
• Mediastinal infection
• Cardiac surgery
• Surgical infection