Intranasal mupirocin prophylaxis in elective surgery. A review of published studies.

BACKGROUND: Mupirocin is a natural antibiotic from Pseudomonas fluorescens which is available as a 2% ointment. The drug has been used mainly for topical treatment of the nasal vestibulum in patients carrying methicillin-resistant Staphylococcus aureus (MRSA). However, mupirocin is also active against methicillin-sensitive S. aureus. Nasal colonization with S. aureus has been identified as a significant risk factor for surgical site infection (SSI).

METHODS: Randomized trials and sequential cohort studies investigating mupirocin nasal treatment for prophylaxis of SSI in elective surgery in comparison with placebo or no treatment were found by Medline review and additional manual search. Evaluable studies were analyzed regarding the influence of mupirocin on the rate of all SSIs and, specifically, of SSIs due to S. aureus. The effect in cardiosurgical patients was analyzed in detail.

RESULTS: Four randomized and seven sequential open cohort studies were analyzed. Study design and mupirocin application schemes varied considerably. Three out of 5 studies carried out in cardiac surgery patients showed a significant reduction in sternotomy site infections. However, all three studies were open sequential cohort studies. By contrast, the only prospective, randomized, double-blind study in cardiosurgical patients showed no benefit of mupirocin. In other surgical disciplines, results were inconclusive or negative. Two studies specifically addressing the prevention of SSIs due to MRSA showed a significant effect of mupirocin on postsurgical infections due to this organism.

CONCLUSIONS: Because of the heterogeneity of the studies and the variability of results, no recommendation can be given for the general use of mupirocin in elective surgical patients. Specifically, because of the negative result of a recently published high-quality study, no recommendation can be made for the use of mupirocin in cardiosurgical patients. By contrast, eradication of MRSA before surgery appears to lower SSI rates due to MRSA and is therefore recommended.