Preoperative shower revisited: can high topical antiseptic levels be achieved on the skin surface before surgical admission?

BACKGROUND

Skin asepsis is a sentinel strategy for reducing risk of surgical site infections. In this study, chlorhexidine gluconate (CHG) skin concentrations were determined after preoperative showering/skin cleansing using 4% CHG soap or 2% CHG-impregnated polyester cloth.

STUDY DESIGN

Subjects were randomized to one of three shower (4% soap)/skin cleansing (2% cloth) groups (n = 20 per group): (group 1 A/B) evening, (group 2 A/B) morning, or (group 3 A/B) evening and morning. After showering or skin cleansing, volunteers returned to the investigator's laboratory where CHG skin surface concentrations were determined at five separate skin sites. CHG concentrations were compared with CHG minimal inhibitory concentration that inhibits 90% (MIC(90)) of staphylococcal skin isolates.

RESULTS

CHG MIC(90) for 61 skin isolates was 4.8 parts per million (ppm). In group 1A, 4% CHG skin concentrations ranged from 17.2 to 31.6 ppm, and CHG concentrations were 361.5 to 589.5 ppm (p < 0.0001) in group 1B (2%). In group 2A (4%), CHG levels ranged from 51.6 to 119.6 ppm and 848.1 to 1,049.6 ppm in group 2B (2%), respectively (p < 0.0001). CHG levels ranged from 101.4 to 149.4 ppm in the 4% CHG group (group 3A) compared with 1,484.6 to 2,031.3 ppm in 2% CHG cloth (group 3B) group (p < 0.0001). Effective CHG levels were not detected in the 4% CHG group in selected sites in seven (35%) subjects in group 1A, three (15%) in group 2A, and five (25%) in group 3A.

CONCLUSIONS

Effective CHG levels were achieved on most skin sites after using 4% CHG; gaps in antiseptic coverage were noted at selective sites even after repeated application. Use of the 2% CHG polyester cloth resulted in considerably higher skin concentrations with no gaps in antiseptic coverage. Effective decolonization of the skin before hospital admission can play an important role in reducing risk of surgical site infections.