Tracheostomy: A risk factor for mediastinitis after cardiac operation

Background. We studied whether tracheostomy after coronary artery bypass gr afting (CABG) is associated with higher incidence of mediastinitis and mort ality, and whether shorter intervals between median sternotomy and tracheot omy are associated with higher incidence of mediastinitis. Methods. Patients (n = 6,057) undergoing CABG since March 1977 were reviewe d. Patients requiring tracheostomy and those developing mediastinitis were identified. Mediastinitis diagnosis required positive culture of mediastina l tissue or fluid. Results. After CABG, 88 patients had tracheostomy performed (1.45%). Seven patients receiving tracheostomy after developing mediastinitis were exclude d. Of the remaining 81 patients, 7 developed mediastinitis (8.6%) compared with 44 of 5,969 (0.7%) who did not require tracheostomy (p < 0.001). Morta lity in tracheostomy patients was 24.7% (20 of 81) compared with 5.2% in pa tients not requiring tracheostomy (316 of 5,969; p < 0.001). Patients not d eveloping mediastinitis had tracheostomy placement an average of 25 days af ter CABG compared with 18.7 days for those developing mediastinitis (p = 0. 141). Conclusions. Tracheostomy after CABG is associated with increased incidence of mediastinitis and mortality. In this review, the time interval between CABG and tracheostomy was not predictive of mediastinitis. A larger sample size would be required to be confident that there is no correlation. (C) 20 01 by The Society of Thoracic Surgeons