Incremental antibiotic regimen no more effective than single dose
A single, pre-operative dose of the anti-biotic cefazolin is traditionally given to patients undergoing implantation of an implantable cardiac rhythm management device. But this doesn’t protect against 30% of the microorganisms that cause infection, according to lead author Dr. Andrew Krahn.
Infections occur in just 2% of CRM implantation patients, making them “uncommon but catastrophic,” Krahn said. That’s why researchers from the University of British Columbia, led by Krahn, sought to determine whether using an incremental perioperative antibiotics strategy would be better at preventing device infection compared to a single, pre-operative cefazolin dose.
The study ultimately evaluated device procedures in 19,603 high-risk patients, with a primary outcome of hospitalization for device infection within one year.
For the incremental treatment approach, doctors used a combination of pre-surgical cefazolin and vancomycin, a bacitracin pocket wash and post-operative oral cephalexin for two days.
Although the study missed its primary endpoint, Krahn noted that the infection rate for both arms of the trial hovered at around 1% – much lower than the study’s authors anticipated.
“We’re talking about 177 infections across almost 20,000 patients – it’s not very many. That limits the ability of the study to find those kinds of trends to be significant. They’re speculative, but they’re certainly hypothesis-generating,” he explained. “In the end, this design of study allowed us to enroll a large number of patients, to evaluate the efficacy of this four-arm, incremental antibiotics strategy and find, at best, a modest trend towards a benefit with that incremental strategy.”