Risk factors for mediastinitis and mortality in pneumomediastinum

Introduction: Pneumomediastinum (PM) is a self-limiting disease with a good prognosis. Mediastinitis is a rare but potentially fatal complication of PM. Identification of risk factors for mediastinitis is essential for better management.
Methods: This is a single-center, retrospective study conducted in a university hospital. Adult patients with PM between January 2016 and June 2020 were involved in the study. The data about age, gender, symptoms, signs, treatment, development of mediastinitis, hospital stay, and mortality were investigated.
Results: In total, 79 patients with PM were analyzed. The most common symptom was dyspnea(58;73.4%) and the most common sign was subcutaneous emphysema (48;60.7%). Thirty(37.9%) of them were iatrogenic PM (IPM), while 22 (27.9%) were spontaneous PM (SPM) and27 (34.2%) were traumatic PM (TPM). Mediastinitis developed in 17 (12 from IPM, 4 from TPM,1 from SPM) patients, and 11 (58.8%) of these patients died. The incidence of mediastinitis in the IPM group was significantly higher than in the TPM and SPM group (respectively, P=0,03,P=0,01). There was no significant difference between the age, gender, symptoms, and signs of those with or without mediastinitis. Mortality was lower in TPM and SPM than IPM (respectively,P=0,05, P=0,03), and hematological malignancy was remarkably common in patients who died from mediastinitis in the TPM and SPM group.
Conclusion: Mediastinitis and mortality were significantly higher in IPM, while hematological malignancy was remarkably prevalent in patients deceased from mediastinitis in TPM and SPM.