SAN DIEGO – Preoperative nasal application of a povidone-iodine solution may be more efficacious than nasal mupirocin for preventing deep surgical site infections caused by Staphylococcus aureus, a study has shown.
Investigators led by Dr. Michael Phillips of the New York University Langone Medical Center conducted a randomized trial, assigning 1,697 patients undergoing arthroplasty or spine fusion surgery evenly to the two treatments. All patients in the study also underwent chlorhexidine cleansing of the skin and received standard antimicrobial prophylaxis.
Trial results, reported at IDWeek, showed that the rate of S. aureus deep surgical site infections was one-sixth as high in the povidone-iodine group as in the mupirocin group. The povidone-iodine group also had a lower rate of adverse events and less often rated their treatment as unpleasant.
"We feel that individuals should consider the use of nasal povidone-iodine as a component of a multifaceted approach to prevent S. aureus infection after high-risk surgery," Dr. Phillips said.
In the trial, adult patients undergoing arthroplasty or spine fusion surgery at the NYU Hospital for Joint Diseases had nasal cultures for S. aureus before surgery and were then assigned to two groups.
In one group, patients were given 2% mupirocin nasal ointment and told to apply it twice daily for the 5 days leading up to surgery. The mupirocin was provided directly to the patients because a survey suggested that some patients were skipping the mupirocin because of its cost, as it is not routinely covered by insurance, he explained at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
In the other group, research personnel applied a 5% solution of povidone-iodine to both nostrils in patients up to 2 hours before incision.
Both groups also were given chlorhexidine wipes and told to use them from chin to toes the evening before and again the morning of surgery. Both groups received standard perioperative antimicrobial prophylaxis (cefazolin or clindamycin, plus vancomycin for those having a positive nasal culture for methicillin-resistant S. aureus). Both also had surgical site prepping with 2% chlorhexidine and alcohol.
The patients’ median age was 62 years; 60% were women and 80% were white. Preoperative nasal culture results showed that one in five patients was colonized with S. aureus.
The rate of noncompletion of the protocol was 11% in the mupirocin group and 8% in the povidone-iodine group, Dr. Phillips reported. The leading reason for noncompletion in the mupirocin group was failure to apply mupirocin at least seven times. In the povidone-iodine group, it was failure to use the chlorhexidine wipes.
In intent-to-treat analyses, patients in the nasal povidone-iodine group had a 0.7% rate of any deep surgical site infection at 3 months; those in the mupirocin group had a 1.6% rate. The rate of S. aureus deep surgical site infections was 0.1% and. 0.6%, respectively.
In a univariate analysis, patients had a higher risk of S. aureus deep surgical site infection if they were in the mupirocin group (relative risk, 1.01; P = .04) or were colonized with S. aureus preoperatively (relative risk, 6.79; P = .02).
When patients were stratified by colonization status, there was a trend toward a lower rate of S. aureus deep surgical site infection with povidone-iodine versus mupirocin for those who were colonized (P = .08) but not for those who were not.
Patients in the povidone-iodine group had a lower rate of study drug adverse events overall (2% vs. 9%, P less than .0001). The difference was significant for rhinorrhea, headache, congestion, and pharyngeal pain individually.
In addition, patients in the povidone-iodine group were less likely to report that application of the study medication was unpleasant or very unpleasant (4% vs. 38%).
Dr. Phillips disclosed that he received a research grant from 3M Corp., manufacturer of the povidone-iodine solution. The study was supported by 3M.