Reducing Mediastinitis after Sternotomy with Combined Chlorhexidine-Isopropyl Alcohol Skin Disinfection: Analysis of 3,000 Patients.

Background: Reducing surgical site infections (SSI) following median sternotomy remains a challenge for cardiac surgeons. Standard prophylaxis of SSI at our institution includes pre-operative skin disinfection with isopropyl alcohol (IPA). The addition of chlorhexidine gluconate (CHG) has the theoretical advantage of longer antimicrobial activity (>48h), compared with 2 h for IPA alone.

Objectives: This prospective registry study was conducted to evaluate the effect of combined CHG-IPA (ChloraPrep®) skin antiseptic on the incidence of sternal surgical incision infections after cardiac surgical procedures via median sternotomy.

Methods: Between September 2011 and November 2013, 3,942 consecutive patients underwent cardiac surgery with median sternotomy at our institution. Among them, 2,985 patients met inclusion criteria and were enrolled in the study. The complete cohort was prospectively divided into two registries. In registry 1 (1,523 patients), CHG-IPA was used to disinfect skin at the thoracic operative site prior to incision. In registry 2 (1,462 patients), single IPA disinfection was used. The primary endpoint was the incidence of post-sternotomy mediastinitis within 30 d of surgery. Secondary endpoints were SSI of any other kind, 30-d survival, and hospital length of stay.

Results: Both registries were well matched in baseline characteristics and main risk factors. Post-operative data analysis revealed reduction in the rate of post-sternotomy mediastinitis in registry 1 (29 patients, 1.9%) versus registry 2 (62 patients, 4.2%), p = 0.0002. No relevant difference in incidence of other surgical site infections, length of hospital stay, and 30-d mortality was found.

Conclusions: Skin disinfection with combined chlorhexidine-isopropyl alcohol reduced the incidence of mediastinitis in elective adult cardiac surgery with median sternotomy but did not affect other types of surgical site infections.