(245) Comparative Effectiveness of Single-Drug Versus Vancomycin-based Combination Antimicrobial Regimens in Post-Neurosurgical Infections at a Northwest China Hospital

Background: Post-neurosurgical induced intracranial infections have high mortality rates, necessitating early empirical anti-infection treatment. Despite guidelines favoring a vancomycin-based combination regimen, its initial use may be limited due to bacterial resistance and antimicrobial stewardship policies.

Objectives: To evaluate initial antimicrobial treatment regimens and their effectiveness for post-neurosurgical infections at a Northwest China hospital.

Methods: A retrospective cohort study was designed, and data from 2019 to 2022 for neurosurgical patients at Xinjiang Medical University’s First Affiliated Hospital were collected in Electronic Medical Records. Adult patients (aged ≥ 18) diagnosed with postoperative central nervous system infections undergoing antimicrobial therapy were included and excluded from brain abscess, severe organ dysfunction, pregnancy, or perinatal women, and/or only perioperative prophylaxis use. Two groups were categorized as single-drug regimens (SDRs) and combination therapy regimens (CTRs). The primary outcome was the treatment effectiveness defined as infection curative. To compare the effectiveness across two regimens, a doubly robust estimation method—combining Inverse Probability of Treatment Weighting and regression—was applied to adjust for age, gender, comorbidities, and surgery duration, in mitigating indication bias.

Results: Of 8,604 patients, 1,188 (13.81%) had postoperative infections. SDRs were the main strategy in 92.3% of cases. The effectiveness rates between SDRs and CTRs were 74.6% vs. 73.9%. There was no significant difference in effectiveness rate between SDRs and CTRs (OR=1.04, 95%CI=0.73, 1.48). Most SDRs involved ceftriaxone (40.42%), and most CTRs were vancomycin-based (86.96%). The duration of surgery (OR=0.91, 95%CI=0.86, 0.97) and age (OR=0.98, 95%CI=0.97, 1.00) were significant factors affecting the choice of treatment regimens. For SDR, the effectiveness of ceftazidime (OR=1.29, 95%CI=0.89, 1.89, p=0.181) and meropenem (OR=0.91, 95%CI=0.60, 2.07, p=0.725) was superior to that of ceftriaxone, whereas the effectiveness of vancomycin was inferior to ceftriaxone (OR=0.83, 95%CI=0.86, 0.97, p=0.442), yet none of these differences were statistically significant. Among the CTRs, there was no statistical difference between the various drugs based on vancomycin.

Conclusions: SDRs, especially ceftriaxone, are the mainstay in treating post-neurosurgical infections with an effectiveness comparable to CTRs. Given the limitations of a single-center study, further research across multiple hospitals is warranted. Additionally, future studies focusing on pharmacoeconomic evaluations are recommended to refine treatment guidelines.