Mediastinal infection after open heart surgery.

Mediastinal infection occurred in 29 of 2031 patients (1.4%) who underwent median sternotomy for cardiac operation at the National Heart, Lung and Blood Institute between 1956 and 1981. Factors associated with the development of mediastinitis included postoperative complications such as low cardiac output, respiratory insufficiency, reoperation for bleeding, repeat median sternotomy, and triple valve replacement. Factors that were not significantly associated with the development of mediastinitis included preoperative functional class, preoperative cardiac index, age, sex, weight, or presence of diabetes mellitus. The mortality rate in patients who developed mediastinitis was 52%. Factors associated with death included preoperative functional class III or IV, type of operation, type of organism involved, and the development of pneumonia. The mortality rate was significantly lower (35% versus 73%) in the patients who underwent mediastinal exploration for treatment. There was no difference in survival whether the wound was closed over drainage tubes or packed open. Hospital stay, however, was significantly prolonged in the patients whose wounds were packed open.