In Neurosurgery, CDI Rates Drop When Extended Antimicrobial Prophylaxis Limited

New research suggests reducing the use of extended antimicrobial prophylaxis in patients undergoing neurosurgical procedures can lower rates of Clostridioides difficile infection (CDI) without substantially increasing the risk of postoperative infection.

Writing in the Journal of Neurosurgery, Mark E. Shaffrey, MD, of the University of Virginia, and colleagues, explained that periprocedural prophylaxis is a common component of neurosurgery. The investigators said the use of prophylaxis is sometimes continued for extended periods of time while surgical drains are in place.

“However, there is little evidence that extended antimicrobial administration is necessary to reduce postprocedural infection,” Shaffrey and colleagues wrote, adding that the overuse of antimicrobials can lead to adverse impacts, such as a heightened risk of CDI.

The investigators wanted to know whether reducing extended use of antimicrobials would affect the risk of infection in general, and CDI in particular.

To find out, they conducted a retrospective analysis of more than 7000 patients who received prophylaxis when undergoing neurosurgery. In total, 7204 patients were included, representing 8586 procedures. A total of 413 external ventricular drain placements were conducted within the study population.

The patients were examined in two chorts. In the first cohort, patients were taken off postoperative antimicrobial prophylaxis within the first 24 hours after surgery. In the second cohort, some patients were allowed to have extended prophylaxis while surgical drains or external ventricular drains were used.

The investigators found a significant drop in rates of CDI when extended postprocedural antibiotics were stopped. In such cases, the overall rate of CDI dropped from 0.5% per procedural encounter to just 0.07% per procedural encounter. Yet, the discontinuation of extended prophylaxis did not appear to affect rates of postprocedural infection or EVD infection in a statistically significant way. The authors said those findings held true even when they examined patients in particular subgroups, such as those with closed suction drains.

The authors said their results suggest limiting postprocedural prophylaxis is a feasible strategy to reduce rates of CDI.

“This study provides evidence to support the specialty-wide discontinuation of extended postoperative antimicrobial prophylaxis, even in the presence of closed suction drains,” they concluded.

The new report builds on earlier research about infection risk in neurosurgery and the use of prophylaxis. For instance, a 2019 study of more than 16,000 patients who underwent neurosurgery found several risk factors for infection, such as wound leak and duration of the procedure.

However, the study found that whether or not physicians used postoperative antibiotics was one of the statistically significant factors affecting rates of surgery site infections.

A separate study, published in 2017, found that in a cohort of 808 patients who underwent neurosurgery, antibiotic prophylaxis had “no preventative effect on postoperative infections.” The study further found that the use of prophylaxis appeared to increase the positive bacterial culture rate and “promote the emergence of multidrug-resistant bacteria.” Like the 2019 study, the authors reported that cerebrospinal fluid leak and procedure duration were more important factors in terms of infection risk.