Orthopedic device-related infection (ODRI) preclinical models are widely used in translational research. Most ODRI models require induction of general anesthesia, which frequently results in hypothermia in rodents. This study aimed to evaluate the impact of peri-anesthetic hypothermia in rodents on outcomes in preclinical ODRI studies. A retrospective analysis of all rodents that underwent surgery under general anesthesia to induce an ODRI model with inoculation of Staphylococcus epidermidis between 2016 and 2020 was conducted. A one-way multivariate analysis of covariance (one-way MANCOVA) was used to determine the fixed effect of peri-anesthetic hypothermia (hypothermic defined as rectal temperature <35°C) on the combined harvested tissue and implant colony-forming unit (CFU) counts, and having controlled for the study groups including treatments received, duration of surgery and anesthesia, and study period. The results showed a significant effect of peri-anesthetic hypothermia on the post-mortem combined CFU counts from the harvested tissue and implant(s) (p = 0.01) when comparing normo- versus hypothermic rodents. Using Wilks’ Λ as a criterion to determine the contribution of independent variables to the model, peri-anesthetic hypothermia was the most significant, though still a weak predictor, of increased harvested CFU counts. Altogether, the data corroborate the concept that bacterial colonization is affected by abnormal body temperature during general anesthesia at the time of bacterial inoculation in rodents, which needs to be taken into consideration to decrease infection data variability and improve experimental reproducibility.

中文翻译：

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啮齿类动物围麻醉期低温：骨科器械相关感染研究中准确和可重复结果的考虑因素

骨科器械相关感染 (ODRI) 临床前模型广泛用于转化研究。大多数 ODRI 模型需要全身麻醉诱导，这经常导致啮齿动物体温过低。本研究旨在评估啮齿动物围麻醉期低温对临床前 ODRI 研究结果的影响。对所有在全身麻醉下进行手术以诱导接种表皮葡萄球菌的 ODRI 模型的啮齿动物的回顾性分析于 2016 年至 2020 年间进行。协方差的单向多变量分析（单向 MANCOVA）用于确定围麻醉期低温（低温定义为直肠温度 <35°C）对联合收获组织和植入物集落形成单位（CFU）的固定影响) 计数，并控制了研究组，包括接受的治疗、手术和麻醉的持续时间以及研究期间。结果表明，围麻醉期低温对采集的组织和植入物的死后联合 CFU 计数有显着影响（p = 0.01) 在比较正常和低温啮齿动物时。使用 Wilks' Λ 作为确定自变量对模型的贡献的标准，麻醉前体温过低是最重要的，但仍然是增加的 CFU 计数的弱预测因子。总而言之，这些数据证实了细菌定植受啮齿动物细菌接种时全身麻醉期间体温异常的影响的概念，需要考虑这一点以减少感染数据的可变性并提高实验的可重复性。