Macki Mohamed, Hamilton Travis, Lim Seokchun, Mansour Tarek R, Telemi Edvin, Bazydlo Michael, Schultz Lonni, Nerenz David R, Park Paul, Chang Victor, Schwalb Jason, Abdulhak Muwaffak M
Departments of1Neurosurgery.
2Public Health Sciences, and.
J Neurosurg Spine. 2021 Sep 17;36(2):254-260. doi: 10.3171/2021.4.SPINE201839. Print 2022 Feb 1.
Despite a general consensus regarding the administration of preoperative antibiotics, poorly defined comparison groups and underpowered studies prevent clear guidelines for postoperative antibiotics. Utilizing a data set tailored specifically to spine surgery outcomes, in this clinical study the authors aimed to determine whether there is a role for postoperative antibiotics in the prevention of surgical site infection (SSI).
The Michigan Spine Surgery Improvement Collaborative registry was queried for all lumbar operations performed for degenerative spinal pathologies over a 5-year period from 2014 to 2019. Preoperative prophylactic antibiotics were administered for all surgical procedures. The study population was divided into three cohorts: no postoperative antibiotics, postoperative antibiotics ≤ 24 hours, and postoperative antibiotics > 24 hours. This categorization was intended to determine 1) whether postoperative antibiotics are helpful and 2) the appropriate duration of postoperative antibiotics. First, multivariable analysis with generalized estimating equations (GEEs) was used to determine the association between antibiotic duration and all-type SSI with adjusted odds ratios; second, a three-tiered outcome-no SSI, superficial SSI, and deep SSI-was calculated with multivariable multinomial logistical GEE analysis.
Among 37,161 patients, the postoperative antibiotics > 24 hours cohort had more men with older average age, greater body mass index, and greater comorbidity burden. The postoperative antibiotics > 24 hours cohort had a 3% rate of SSI, which was significantly higher than the 2% rate of SSI of the other two cohorts (p = 0.004). On multivariable GEE analysis, neither postoperative antibiotics > 24 hours nor postoperative antibiotics ≤ 24 hours, as compared with no postoperative antibiotics, was associated with a lower rate of all-type postoperative SSIs. On multivariable multinomial logistical GEE analysis, neither postoperative antibiotics ≤ 24 hours nor postoperative antibiotics > 24 hours was associated with rate of superficial SSI, as compared with no antibiotic use at all. The odds of deep SSI decreased by 45% with postoperative antibiotics ≤ 24 hours (p = 0.002) and by 40% with postoperative antibiotics > 24 hours (p = 0.008).
Although the incidence of all-type SSI was highest in the antibiotics > 24 hours cohort, which also had the highest proportions of risk factors, duration of antibiotics failed to predict all-type SSI. On multinomial subanalysis, administration of postoperative antibiotics for both ≤ 24 hours and > 24 hours was associated with decreased risk of only deep SSI but not superficial SSI. Spine surgeons can safely consider antibiotics for 24 hours, which is equally as effective as long-term administration for prophylaxis against deep SSI.
尽管对于术前抗生素的使用已达成普遍共识，但比较组定义不明确以及研究样本量不足妨碍了术后抗生素使用的明确指南的制定。在这项临床研究中，作者利用专门针对脊柱手术结果定制的数据集，旨在确定术后抗生素在预防手术部位感染（SSI）方面是否发挥作用。
查询了密歇根脊柱手术改善协作登记处2014年至2019年5年间因退行性脊柱疾病进行的所有腰椎手术。所有手术均使用术前预防性抗生素。研究人群分为三组：不使用术后抗生素、术后抗生素使用≤24小时、术后抗生素使用>24小时。这种分类旨在确定：1）术后抗生素是否有帮助；2）术后抗生素的合适使用时长。首先，使用广义估计方程（GEE）进行多变量分析，以确定抗生素使用时长与所有类型SSI之间的关联及调整后的比值比；其次，通过多变量多项逻辑GEE分析计算三级结果——无SSI（手术部位感染）、浅表SSI和深部SSI。
在37161例患者中，术后抗生素使用>24小时组男性更多，平均年龄更大，体重指数更高，合并症负担更重。术后抗生素使用超过24小时组的SSI发生率为3%，显著高于其他两组2%的SSI发生率（p = 0.004）。在多变量GEE分析中，与不使用术后抗生素相比，术后抗生素使用>24小时组和术后抗生素使用≤24小时组均与所有类型术后SSI发生率降低无关。在多变量多项逻辑GEE分析中，与完全不使用抗生素相比，术后抗生素使用≤24小时组和术后抗生素使用>24小时组均与浅表SSI发生率无关。术后抗生素使用≤24小时组深部SSI的几率降低了45%（p = 0.002），术后抗生素使用>24小时组降低了40%（p = 0.008）。
尽管术后抗生素使用>24小时组中所有类型SSI的发生率最高，且该组危险因素比例也最高，但抗生素使用时长并不能预测所有类型的SSI。在多项亚组分析中，术后抗生素使用≤24小时和>24小时均仅与深部SSI风险降低有关，与浅表SSI无关。脊柱外科医生可以安全地考虑使用抗生素24小时，这在预防深部SSI方面与长期使用同样有效。
