腰椎手術後の早期深部感染例における危険因子の検討

Risk Factors for Deep Infection in the Early Stage after Lumbar Surgery

　腰椎手術後の早期深部感染の実態と感染危険因子について検討した．対象は腰椎手術を受けた患者439例で，感染率，起因菌，治療，予後を検討した．また，多重ロジスティック回帰分析を使用し，患者因子，手術因子および医療者因子に分けた感染危険因子の検討を行った．早期深部感染は9例（2.1％）で，8例で起因菌が同定された．インストゥルメント使用例では4例中2例でインストゥルメントを温存できた．感染危険因子は低蛋白血症，インストゥルメント使用例，再手術例，手術が仙椎にかかる例の4項目であった．

　The purpose of this study was to elucidate risk factors for deep infection in the early stage after lumbar surgery. The rate of deep infection in the early stage, the type of bacteria, treatment for infection, and outcome were assessed in 439 patients underwent lumbar spine surgery for the treatment of lumbar disease. Deep infection had developed in nine of the 439 cases (2.1％), and the causative bacteria were identified in 8 of them. We selected ten possible risk factors for postoperative infection, and a multivariate analysis identified low proteinemia, instrumentation surgery, salvage operations, and operation to the sacrum as risk factors with an odd's ratio of 2.2, 3.1, 2.9, and 3.4, respectively. It is critical to take these factors into account in an attempt to prevent serious postoperative deep infection after lumbar surgery.