Thirteen-year experience with universal Staphylococcus aureus nasal decolonization prior to cardiac surgery: a...

Sternal wound infection (SWI) after cardiac surgery is a severe complication. Among preventive measures, pre-operative decolonization of nasal carriage of Staphylococcus aureus has recently been shown to be beneficial. This quasi-experimental study assessed the effect of decolonization on the incidence of S. aureus-associated SWI based on 19 years of prospective surveillance.

Segmented negative binomial regression was used to analyse the change over time in the incidence of S. aureus mediastinitis requiring re-operation after cardiac surgery in a French university hospital between 1996 and 2014. Universal nasal decolonization with mupirocin was introduced in December 2001. The association between pre-operative nasal carriage and SWI due to S. aureus was analysed between 2006 and 2012.

Among 17,261 patients who underwent a cardiac surgical procedure, 565 developed SWI (3.3%), which was caused by S. aureus in 181 cases (1%). The incidence of mediastinitis caused by S. aureus decreased significantly over the study period (1.43% in 1996-2001 vs 0.61% and 0.64% in 2002-2005 and 2006-2014, respectively; P<0.001). In segmented analysis, there was a significant break in 2002, corresponding to the introduction of decolonization. Despite this intervention, pre-operative nasal carriage remained a significant risk factor for S. aureus mediastinitis (adjusted odds ratio 2.2; 95% confidence interval 1.2-4.2), as were obesity, critical pre-operative status, coronary artery bypass grafting (CABG), and combined surgery with valve replacement and CABG.

Universal nasal decolonization before cardiac surgery was effective in decreasing the incidence of mediastinitis caused by S. aureus. Nasal carriage of S. aureus remained a risk factor for S. aureus-associated SWI.