THORACIC AND RESPIRATORYDISORDERSEXAM
■ Crepitus suggestive of subcutaneous air is the most common finding.
■ Hamman signis a crunching sound that is synchronous with the heart
beat. It is uncommonly seen, but when present, it is highly suggestive of
pneumomediastinum.
■ Often there is no physical abnormality.
DIAGNOSIS
■ CXR: Most easily seen on lateral view; a thin line of radiolucency that out-
lines the heart and mediastinal structures
■ CT: More sensitive than CXR; may also provide the etiology of the air, eg,
esophageal perforation
■ Esophagoscopy if esophageal perforation is suspected
■ Bronchoscopy if tracheobronchial perforation is suspected
TREATMENT
■ Most cases resolve spontaneously.
■ Admission or observation is indicated if symptoms are severe or if there is
suspicion for pneumothorax, tension pneumothorax, or mediastinitis.
■ Surgery is rarely needed.
■ Antibiotics are indicated if esophageal perforation is suspected.
COMPLICATIONS
Pneumothorax, tension pneumothorax, mediastinitis
MEDIASTINITIS■ A very serious, life-threatening condition that usually occurs after a med-
ical procedure, eg, cardiac surgery, endoscopy, or bronchoscopy
■ Can also result from esophageal perforation, trauma, upper respiratory
infection, or an odontogenic infection (resulting in descending necrotiz-
ing mediastinitis)
■ Risk factors include malignancy, immunocompromise, autoimmune dis-
ease, diabetes, and illicit drug use.
■ S. aureusandS. epidermidisaccount for the majority of cases (70–80%)
after cardiac surgery. Anaerobic organisms are common in non-iatrogenic
infections. Mixed infections, including Pseudomonas, are common. Rarely,
Histoplasmosisinfection may cause a fibrosing mediastinitis.
SYMPTOMS
■ Chest pain often worsened by inspiration radiating to the neck or upper
back
■ Dyspnea
■ Confusion
■ Sore throat or dental pain if odontogenic
■ Drainage from surgical site
EXAM
■ Fever and tachycardia
■ Audible click of an unstable sternum
■ Subcutaneous emphysema