Bacterial recolonization of the skin and wound contamination during cardiac surgery: a randomized controlled trial of the use of plastic adhesive drape compared with bare skin.

BACKGROUND Sternal wound infection after cardiac surgery is a serious complication. Various perioperative strategies, including plastic adhesive drapes, are used to reduce bacterial contamination of surgical wounds. AIM To compare plastic adhesive drape to bare skin regarding bacterial growth in wound and time to recolonization of the adjacent skin intraoperatively, in cardiac surgery patients. METHODS This single-blinded randomized controlled trial (May 2010 to May 2011) included 140 patients scheduled for cardiac surgery via median sternotomy. The patients were randomly allocated to the adhesive drape (chest covered with plastic adhesive drape) or bare skin group. Bacterial samples were taken preoperatively and intraoperatively every hour during surgery until skin closure. RESULTS Disinfection with 0.5% chlorhexidine solution in 70% alcohol decreased coagulase-negative staphylococci (CoNS), while the proportion colonized with Propionibacterium acnes was not significantly reduced and was still present in more than 50% of skin samples. P. acnes was significantly more common in men than in women. Progressive bacterial recolonization of the skin occurred within 2-3 h. At 120 min there were significantly more positive cultures in the adhesive drape group versus bare skin group for P. acnes (63% vs 44%; P = 0.034) and for CoNS (45% vs 24%; P = 0.013). The only statistically significant difference in bacterial growth in the surgical wound was higher proportion of CoNS at the end of surgery in the adhesive drape group (14.7% vs 4.4%; P = 0.044). CONCLUSION Plastic adhesive drape does not reduce bacterial recolonization. P. acnes colonized men more frequently, and was not decreased by disinfection with chlorhexidine solution in alcohol.