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Pneumomediastinum. Tyler Bagley October 17, 2006. Objectives. 1. Recognize the causes of pneumomediastinum 2. Recognize the presentation 3. Identify common radiological signs 4. Discuss when to order additional tests 5. Treatment.
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Pneumomediastinum Tyler Bagley October 17, 2006
Objectives • 1. Recognize the causes of pneumomediastinum • 2. Recognize the presentation • 3. Identify common radiological signs • 4. Discuss when to order additional tests • 5. Treatment
Rupture of the alveolus with air dissection along the peribronchial vascular sheaths into the hilum and mediastinum Ruptured bleb with peripheral extension Sudden rise in intrapulmonary pressure Asthma, vomiting, forceful coughing, crying, shouting, Valsalva maneuver, artificial ventilation, closed chest trauma, sudden drop in atmospheric pressure, foreign body aspiration Pulmonary Causes:
Trauma • Rupture of trachea or mainstem bronchus, usually via accidental trauma • Trauma to the neck • Boerhaave’s Syndrome • Barotrauma
Mediastinum Connections • The mediastinum communicates with the submandibular space, retropharyngeal space and vascular sheaths within the neck • Also can communicate with the retroperitoneum via sternocostal attachments to the diaphragm, as well as the periaortic and periesophageal fascial planes
Presentation • Infants-typically none • Adults- • May complain of retrosternal chest pain radiating down both arms that is exacerbated by respiration and swallowing • Dyspnea-in association with asthma, tension PM or pneumothorax • Fever-due to cytokine release with an air leak • Throat or jaw pain, dysphonia, dysphagia, neck swelling and torticollis
Physical Exam • Subcutaneous Air • Associated Pneumothorax • Oxygen Saturations • Hamman’s Sign- • “Crunching” sound heard over the apex of the heart with the cardiac cycle
Extrapleural Sign • Air from the mediastinum can extend laterally between the parietal pleura and the diaphragm to produce the extrapleural sign
Double Bronchial Sign • Air in the mediastinum and left main bronchus allows visualization of both sides of the bronchial wall.
Spinnaker Sign (Thymic Sail Sign) With sufficient mediastinal air, the thymus can become elevated, creating the Thymic Sail Sign, or Spinnaker Sign.
Diagnostic Procedures • Chest tube in coexisting pneumothorax • Bronchoscopy if tracheobronchial perforation is suspected • Esophagoscopy if an esophageal perforation is suspected
Treatment • Mechanical ventilation with low pressure or tidal volumes • Mediastinoscopy to alleviate life-threatening pneumomediastinum • Percutaneous placement of mediastinal drains