[Does nasal decontamination reduce the incidence of infections after cardiac surgery?]

Mupirocin applied to the anterior nares four times daily usually eliminates Staphylococcus aureus, including methicillin resistant, within 48 hours. Prophylactic intranasal mupirocin is safe, inexpensive and effective in reducing the overall sternal wound infection after open-heart surgery. This study was designed to determine whether decreasing nasal bacterial colonization by applying mupirocin intra nasally decreases mediastinal, sternal, pulmonary and cutaneous infections after open-heart surgery.

After institutional approval and informed consent, 392 patients were included in a randomized, prospective study. Nasal cultures were taken for all patients before surgery. Patients were divided in two groups: Group I (n = 190) receiving mupirocin in the anterior nares 4 times daily for 48 hours before surgery; Group II (n = 202) was the control group. Patients were followed for a month after surgery. All mediastinal, sternal, pulmonary and cutaneous infections were documented and treated with appropriate antibiotics. A Student test for quantitative data and a chi2 test for qualitative data were used for statistical analysis. p < or = 0.05 was considered significant.

The two groups had the same demographic characteristics and risk factors. Nasal carriage of Staphylococcus was 36.2% in the two groups. Neither mediastinitis nor sternitis were noticed in any of the two groups. There was no statistical difference between the groups according to the frequency of the cutaneous infections (Group I: 19/190 - Group II: 13/202) and pneumonia (Group I: 7/190 - Group II: 13/202). In patients who had nasal carriage of Staphylococcus, nasal decontamination has not shown a statistical difference of cutaneous infections of the lower limbs nor pneumonia. Although nasal decontamination reduced the incidence of sternal wound infection (Gr I 0/190 - Gr II 4/202 ; p = 0.017). Staphylococcus aureus, in the control group, induced more cutaneous infections (30.8% vs 11.7% ; p = 0.048).

The usage of mupirocin for nasal decontamination before open-heart surgery reduces the incidence of the sternal wound infection, and does not seem to affect the frequency of cutaneous infections of the lower limbs nor pneumonia after this surgery.