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Does Addition of Tobramycin Powder Reduce Infection Rates After Spine Surgery?
Yu-Po Lee1, Saifal-Deen Farhan1, Arif Pendi1
1University of California, Irvine, Orange, CA, USA.
Study Design:
Retrospective chart review.
Objectives:
To evaluate the efficacy of tobramycin and vancomycin powder in reducing surgical site infections in posterior lumbar instrumented fusion.
Methods:
A multicenter, electronic database search was conducted for all patients who underwent posterior instrumented lumbar fusions.
Results:
The addition of vancomycin powder decreased postoperative infections from an incidence of 5.7% down to a rate of 2.0%. This difference was statistically significant (P = .018). The addition of tobramycin powder to the wound in addition to vancomycin further decreased the infection rate down to 1.8%. The postoperative infection rate was statistically significant (P = .041) when compared with the no-powder group. However, the difference was not statistically significant (P = 1.00) when compared with vancomycin alone. There was also a trend toward gram-negative organisms with the addition of more antibiotic powder. In the control group, for example, the organisms cultured were 66% methicillin-sensitive Staphylococcus aureus and 33% gram-negative organisms. In the vancomycin group, 30% of the organisms cultured were Staphylococcus aureus and 60% gram-negative organisms. In the vancomycin and tobramycin powder group, 100% of the organisms cultured were gram-negative.
Conclusions:
There is a reduction in surgical site infections with addition of antibiotic powder to the wound prior to closure. However, the reduction in the infection rate was not as great with the addition of tobramycin powder to vancomycin alone and there was a noticeable change in the spectrum of organism cultured with this addition. Clinicians should consider the risk-to-benefit ratio in each case when deciding to use antibiotic powder.
Insights
Adding antibiotic powder, specifically vancomycin, to surgical wounds significantly reduced surgical site infections in posterior lumbar fusion patients. While tobramycin further decreased infection rates, it also altered the types of bacteria, necessitating careful consideration of risks and benefits.
Area of Science:
- Spine Surgery
- Infectious Disease
- Surgical Innovation
Background:
- Surgical site infections (SSIs) are a significant complication following posterior lumbar instrumented fusion.
- Optimizing prophylactic measures is crucial to minimize patient morbidity and healthcare costs.
Purpose of the Study:
- To evaluate the efficacy of intraoperative vancomycin and tobramycin powder in reducing SSIs in posterior lumbar instrumented fusion.
- To analyze the impact of antibiotic powder on the spectrum of bacterial organisms causing SSIs.
Main Methods:
- Retrospective chart review of patients undergoing posterior instrumented lumbar fusions.
- Multicenter electronic database search to identify patient cohorts.
- Comparison of SSI rates between groups receiving no antibiotic powder, vancomycin powder, and vancomycin plus tobramycin powder.
Main Results:
- Vancomycin powder significantly reduced SSIs from 5.7% to 2.0% (P = .018).
- Addition of tobramycin powder to vancomycin further decreased SSIs to 1.8% (P = .041 vs. no powder), but not significantly compared to vancomycin alone (P = 1.00).
- Antibiotic powder use correlated with a shift towards gram-negative organisms, particularly with the addition of tobramycin.
Conclusions:
- Intraoperative antibiotic powder, particularly vancomycin, is effective in reducing SSIs after posterior lumbar fusion.
- While tobramycin may offer a marginal additional benefit in reducing infection rates, it alters the microbial spectrum, warranting careful risk-benefit assessment.
- Clinicians should weigh the potential benefits against the risks of altered bacterial resistance patterns when considering antibiotic powder use.
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