Fujita Ryo, Takahata Masahiko, Kokabu Terufumi, Oda Itaru, Kajino Tomomichi, Hisada Yuichiro, Takeuchi Hirohito, Iwasaki Norimasa
Department of Orthopedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan.
Department of Orthopedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan.
J Orthop Sci. 2019 Nov;24(6):963-968. doi: 10.1016/j.jos.2019.09.002. Epub 2019 Sep 21.
This study aimed to identify the incidence and causes of a second rise in C-reactive protein (CRP) levels following spinal instrumentation surgery and to help determine how an abnormal CRP response should be interpreted and managed during postoperative care.
The medical records of 948 patients who underwent instrumented spine fusion surgery and met the inclusion criteria were retrospectively reviewed to assess the frequency and causes of a second rise (SR) of CRP. A SR of CRP was defined when the CRP level after postoperative day 7 increased by more than 0.5 mg/dl from that at the previous time-point. The diagnostic cut-off value of CRP elevation for detection of surgical site infection (SSI) was determined. Cut-off values were analyzed using receiver operating characteristic (ROC) curves. Bayes' theorem was used to determine blood test posterior probabilities for SSI-positive cases using cutoff values of re-evaluated CRP levels.
SR of CRP occurred in 107 of the 948 patients. Of the patients with SR of CRP, 38 (35%) patients had developed SSI, 33 (31%) patients had causes other than SSI, and the remaining 36 patients had unidentified causes. Among the patients with SR, excluding those with causes other than SSI, the best diagnostic cut-off value of SR for detection of SSI was 3.04 mg/dl (area under the curve was 0.74). The posterior test probability was 84.4%.
For patients with SR of CRP, who had no causes other than SSI, an SR value of 3.04 mg/dl correlated with a high probability of developing SSI.
本研究旨在确定脊柱内固定手术后C反应蛋白（CRP）水平再次升高的发生率及原因，并有助于确定术后护理期间应如何解释和处理异常的CRP反应。
回顾性分析948例行脊柱融合内固定手术且符合纳入标准患者的病历，以评估CRP再次升高（SR）的频率及原因。CRP的SR定义为术后第7天之后的CRP水平较前一时间点升高超过0.5mg/dl。确定用于检测手术部位感染（SSI）的CRP升高的诊断临界值。使用受试者工作特征（ROC）曲线分析临界值。采用贝叶斯定理，根据重新评估的CRP水平临界值确定SSI阳性病例的血液检测后验概率。
948例患者中有107例出现CRP的SR。在出现CRP的SR的患者中，38例（35%）发生了SSI，33例（31%）有SSI以外的原因，其余36例原因不明。在出现SR的患者中，排除有SSI以外原因的患者，检测SSI的SR的最佳诊断临界值为3.04mg/dl（曲线下面积为0.74）。后验检测概率为84.4%。
对于无SSI以外原因的CRP的SR患者，SR值为3.04mg/dl时发生SSI的可能性较高。
