Surgical specialty, MRSA risk drive use of vancomycin for surgical prophylaxis
Surgical specialty — namely, cardiac and orthopedic procedures — and the perception of high MRSA prevalence in a facility were the main factors that influenced the prescribing of vancomycin as surgical prophylaxis, according to a study conducted in a Veterans Affairs cohort.
“When we started the study, we thought that the major drivers of vancomycin use would be allergy to beta-lactams and known MRSA colonization, but surprisingly, that was not the case,” Westyn Branch-Elliman, MD, MMSc, assistant professor of medicine at Harvard Medical School and attending physician in infectious diseases in the Veterans Affairs (VA) Boston Healthcare System, told Healio. “We hope this information about what drives the prescribing behavior can be used to improve perioperative antimicrobial stewardship.”
Branch-Elliman and colleagues assessed veterans who underwent major cardiac, orthopedic total joint replacement, vascular or colorectal procedures and were entered into the External Peer Review Program (EPRP) database, which included a manual review of surgery type and duration of prophylaxis, from Oct. 1, 2008 through Sept. 30, 2013. These patients were then matched to the VA Surgical Quality Improvement Program database, which included postoperative variables, such as 7-day acute kidney injury outcomes and 30-day surgical site infection outcomes.
Results of the study showed that among 79,092 cardiac, orthopedic, vascular and colorectal procedures that were performed at 109 different VA facilities nationwide, a quarter of them (25.8%) included vancomycin alone (33.8%) or in combination with another agent for surgical prophylaxis. In this group of patients, 14,200 had a reason for vancomycin documented in the EPRP dataset; 6,188 had no indication noted.
In total, 2,906 patients (3.68%) were colonized with MRSA preoperatively including 1,116 patients (38.4%) who received vancomycin. According to the study, the use of vancomycin as a prophylactic agent was highest among patients who underwent cardiac surgeries (48.9%), followed by orthopedic procedures (20.8%). Use of vancomycin in vascular and colorectal procedures was substantially lower (22.6% and 3.3%, respectively).
According to the study results, only 3.2% of the vancomycin used for surgical prophylaxis was given to patients with known MRSA colonization or a history of MRSA infection (503/15,726). The researchers that perceptions of high rates of MRSA in the facility and/or a procedure determined to be at high risk for MRSA were the most likely reasons noted for vancomycin administration overall (46.9%); cardiac and orthopedic surgeries were also more likely to involve vancomycin prophylaxis (49.5% and 48.4%, respectively). Allergy and/or intolerance to a beta-lactam antibiotic was the second most likely reason overall (34%) and the most common reason among vascular (43%) and colorectal procedures (48.4%). A perceived high personal risk for MRSA, either because of prolonged health care exposure, a prolonged hospital stay, residing in a nursing home or being colonized with MRSA, was the third most likely reason (15%), according to the study.
“Another key finding was that kidney injuries were increased in patients who received vancomycin for surgical prophylaxis, regardless of the reason vancomycin was chosen,“ Branch-Elliman said. “This suggests that vancomycin itself is associated with increased risk of kidney injury, rather than just being a marker for a sicker patient population.”
The rate of MRSA colonization was greater in patients who received vancomycin than those who did not (5.48% vs. 3.08%; P < .0001), especially among patients with a history of MRSA colonization (37.8%).
“We expected to find that the most common reasons for vancomycin use were beta-lactam allergy and known history of MRSA or MRSA colonization, but we instead found that the two biggest drivers were provider perception of patient risk and type of surgery,” Branch-Elliman said. “Another important finding was that choice of vancomycin was associated with increases in postoperative complications, regardless of the reason behind the choice. We hope that these findings can be used by antimicrobial stewardship programs to improve perioperative care.” – by Caitlyn Stulpin
Disclosure: Branch-Elliman reports serving as an expert witness for DLA Piper, LLC. Please see the study for all other authors’ relevant financial disclosures.