Up to 4 percent of children who undergo surgery that includes cutting the breastbone (sternotomy) develop mediastinitis (infection of the chest cavity). Bloodstream infection (BSI) complicates postoperative mediastinitis in over half of cases. Children who develop postoperative chest cavity infections due to Staphylococcus aureus (S. aureus) have over 6 times higher risk of developing BSI than they do with mediastinitis caused by other pathogens, concludes a study supported in part by the Agency for Healthcare Research and Quality (HS10399).
The researchers retrospectively studied children who developed mediastinitis after median sternotomy between 1995 and 2003 at one urban children's hospital. They examined the following postoperative factors: time to onset of mediastinitis after surgery; tissue and blood culture results; need for extracorporeal membranous oxygenation; duration of hospitalization; duration of intensive care unit stay, requirement of delayed sternal closure or postoperative sternal reexploration; and presence of thoracostomy tubes, endotracheal tubes, intracardiac intravascular catheters, and central venous catheters.
A total of 43 children met the criteria for mediastinitis. Infection occurred a median of 11 days after surgery. Positive blood cultures occurred before diagnosis of mediastinitis in 43 percent of children, on the same day as mediastinitis diagnosis in 48 percent, and after the diagnosis in 9 percent. Mediastinitis caused by S. aureus increased the risk for BSI six-fold, after adjusting for other factors. After adjusting for S. aureus, there was no significant association of BSI with other variables, including delayed sternal closure and intracardiac intravascular catheter duration.
See "Staphylococcus aureus as a risk factor for bloodstream infection in children with postoperative mediastinitis," by Samir S. Shah, M.D., Ebbing Lautenbach, M.D., M.P.H., M.S.C.E., Caroline B. Long, M.D., and others, in the September 2005 Pediatric Infectious Disease Journal 24(9), pp. 834-837.