From the Department of Orthopaedic Surgery, University of Chicago Medicine, Chicago, IL (Dr. Liedl and Dr. Strelzow), and the Pritzker School of Medicine, University of Chicago, Chicago, IL (Dr. Liedl, Dr. Lazenby, Dr. Arimoto, and Mr. Singh).
J Am Acad Orthop Surg Glob Res Rev. 2024 Jun 14;8(6). doi: 10.5435/JAAOSGlobal-D-23-00227. eCollection 2024 Jun 1.
Surgical site infection (SSI) is the leading cause of nosocomial infections among surgical patients in the United States. Currently, there is compelling evidence suggesting that temperature dysregulation in surgical patients may be a risk factor for the development of SSI. We examined the relationship between perioperative hypothermia (PH) and SSI in a population of surgical patients with diabetes mellitus (DM).
This retrospective cohort review was conducted on patients with a history of DM undergoing orthopaedic surgery at our institution between May 1, 2018, and April 1, 2022. Inclusion criteria were age older than 15 years, a history of DM or recent hemoglobin A1c concentration of ≥6.5%, and operation of at least 60 minutes under general anesthesia. Perioperative hypothermia was defined as an intraoperative temperature ≤ 35.5°C. Continuous variables were compared using the t-test and Wilcoxon rank-sum test. Categorical variables were compared using the chi-squared test. We constructed a multivariable logistic regression model to estimate SSI risk while controlling for demographic variables.
A total of 236 patients were included in the final analysis. The overall incidence of SSI was 5.93%. 99 patients (42%) experienced PH. No difference was observed in the risk of SSI between the normothermic and hypothermic cohorts. Among the 99 patients who experienced PH, increasing HbA1c was associated with increasing risk of SSI (OR = 2.39, 95% CI = 1.12 to 5.32, P-value = 0.0222). The multivariable logistic regression model had good discriminatory ability (c-statistic 0.74, 95% CI: 0.61 to 0.89) and good predictive accuracy (sensitivity 64%, specificity 73%).
PH is not an independent risk factor of SSI. However, in the presence of elevated HbA1c, PH may more than double the risk of SSI. Perioperative hypothermia may be an additive risk factor in the setting of poor glycemic control and potentially in the setting of other known risk factors.
手术部位感染（SSI）是美国外科患者医院获得性感染的主要原因。目前，有强有力的证据表明，外科患者体温调节障碍可能是 SSI 发展的一个危险因素。我们研究了围手术期低体温（PH）与糖尿病（DM）患者群体中 SSI 之间的关系。
本回顾性队列研究纳入了 2018 年 5 月 1 日至 2022 年 4 月 1 日在我院接受骨科手术且有 DM 病史的患者。纳入标准为年龄大于 15 岁，有 DM 病史或最近的血红蛋白 A1c 浓度≥6.5%，全身麻醉下手术时间至少 60 分钟。围手术期低体温定义为术中体温≤35.5°C。连续变量采用 t 检验和 Wilcoxon 秩和检验进行比较。分类变量采用卡方检验进行比较。我们构建了多变量逻辑回归模型，以在控制人口统计学变量的情况下估计 SSI 风险。
共有 236 例患者纳入最终分析。SSI 的总发生率为 5.93%。99 例（42%）患者发生 PH。正常体温组和低体温组 SSI 风险无差异。在 99 例发生 PH 的患者中，HbA1c 升高与 SSI 风险增加相关（OR=2.39，95%CI=1.12-5.32，P 值=0.0222）。多变量逻辑回归模型具有良好的区分能力（c 统计量 0.74，95%CI：0.61-0.89）和良好的预测准确性（敏感性 64%，特异性 73%）。
PH 不是 SSI 的独立危险因素。然而，在 HbA1c 升高的情况下，PH 可能使 SSI 的风险增加一倍以上。在血糖控制不佳的情况下，PH 可能是一个附加的危险因素，在其他已知危险因素的情况下也可能如此。
