Application of dermal chlorhexidine antisepsis is ineffective at reducing <i>Proprionibacterium acnes</i> colonization in shoulder surgery.

Abstract

Chlorhexidine as a skin surface antiseptic has been shown to be ineffective with respect to reducing <i>Proprionibacterium acnes</i> colonization within the dermis. The purpose of the present study was to determine whether the application of aqueous chlorhexidine solution to the dermal layer decreased <i>P. acnes</i> colonization during open shoulder surgery. The present study enrolled 50 patients who were undergoing open shoulder surgery. Patients received standard antimicrobial preparation. Three dermal swabs were taken from each patient: swab 1 following skin incision; swab taken 2 minutes to 5 minutes post-application of aqueous chlorhexidine to the dermis; and swab 3 taken 60 minutes post-application. Mean age was 57.5 years (22 males, 28 females). There were 21 patients (42%) with <i>P. acnes</i> present on any dermal swab. There were significantly more <i>P. acnes</i> positive cultures identified at swab 3 compared to swab 1 (<i>p</i> = 0.043). In nine patients with positive <i>P. acnes</i> at cultures swab 1, eight also isolated <i>P. acnes</i> after at swabs 2 or 3. Males were significantly more likely to have <i>P. acnes</i> on any swab (<i>p</i> < 0.001). Positive <i>P. acnes</i> cultures were significantly more common in patients ≤50 years (<i>p</i> < .001). None of the patients had any clinical signs of infection at a minimum of 1 year following surgery. Dermal application of aqueous chlorhexidine during open shoulder surgery fails to eradicate or reduce <i>P. acnes</i> on deep cultures.