Acute mediastinitis: evaluation of clinical risk factors for death in surgically treated patients.

Background: Acute mediastinitis (AM) is the most lethal form of infection within the thorax. The authors of this study, using statistical tools, made an attempt to determine the most important clinical risk factors in retrospective material of patients treated surgically due to AM.

Methods: A total of 44 consecutive patients with AM were subjected to surgery. The aetiology was differentiated: iatrogenic (19), traumatic (11), descending mediastinitis (9) and neoplastic (5). A statistical analysis was performed using chi-square test with Yates correction and analysis of variance test to investigate the correlation between mortality and selected risk factors such as age, gender, aetiology, microbiology, delay between the diagnosis and surgery, coexisting diseases and the kind and number of post-operative complications.

Results: The general death rate was 31.82%. Aetiology was associated with mortality: neoplastic (100%), descending (33.3%), iatrogenic (26.3%) and post-traumatic (9.1%). The following types of bacteria were isolated: aerobes (65.9%), anaerobes (25%) and mixed flora (9.1%). The prognosis was not related to age, gender or the kind of the pathogen. The risk of death increased depending on the number of preoperative co-morbidities (P = 0.0446), particularly on the occurrence of a neoplasm (P = 0.0104). Early qualification for surgery (<24 h) resulted in lower death rate (P = 0.085). Manifestation of more than two post-operative complications (P = 0.0007) should be listed as one of the most negative risk factors.

Conclusions: The knowledge of negative prognostic factors can appear to be a crucial tool enabling one to work out a better therapeutic strategy for high-risk patients with AM.