BackgroundAcute mediastinitis is a serious complication; it occurs after esophageal perforation and thoracic surgery and is rarely due to infections. Clinical and computed tomographic scan signs may be nonspecific, especially in postoperative patients.DesignWe prospectively evaluated the value of transesophageal endosonography with guided fine-needle aspiration in the diagnosis and identification of etiologic agents in critically ill patients with suspected posterior mediastinitis.SettingUniversity hospital.Patients and MethodsTransesophageal endosonography/fine-needle aspiration was performed at the bedside in the intensive care unit with a Pentax 34UX echo-endoscope and a portable Hitachi console (EUB 525). Eighteen patients with clinically suspected mediastinitis were examined with intensive care team support.ResultsComputed tomography was performed before transesophageal endosonography in all 18 patients and was inconclusive in 9. Transesophageal endosonography detected mediastinal lesions in 16 (89%) of 18 patients and was more accurately diagnostic than computed tomography (p= .0082). Fifteen patients had undergone surgery (11 esophagectomy, 1 other esophageal surgery, 1 head/neck cancer surgery, 1 complication after dilatational tracheostomy, and 1 with intervention after polytrauma). Three patients were suspected to have nonpostoperative mediastinitis. In 16 patients, infectious organisms were detected (bacterial, n = 14; fungal, n = 1; tuberculosis, n = 1). Culture and sensitivity of transesophageal endosonography/fine-needle aspiration specimens led to appropriate drug therapy. In two patients, methicillin-resistantStaphylococcus aureuswas detected, leading to isolation care. Twelve patients improved; six died. Of the two patients in whom transesophageal endosonography did not detect a mediastinitis, one was false negative on autopsy. There were no complications.ConclusionBedside transesophageal endosonography/fine-needle aspiration of posterior mediastinal lesions in critically ill patients was an effective and relatively noninvasive way to detect mediastinitis and provide material to identify the etiologic agent. It was particularly useful in postesophagectomy patients.