Pneumomediastinum
Background
- Also known as mediastinal emphysema
- Definition: air present in the mediastinum
- Usually occurs due to sudden increase in intra-alveolar pressure causing alveolar rupture → air dissects into pulmonary interstitium and then into mediastinum, neck, or pericardium[1]
- Life threatening causes include esophageal rupture or tension pneumothorax
- If no hemodynamic or airway compromise present, spontaneous pneumomediastinum is not a life threatening condition
Causes
- Recreational drug use (via inhalation) - cocaine, methamphetamine, marijuana[2]
- Hydrocarbon inhalation
- Asthma/COPD (Spontaneous or secondary to forceful coughing in the setting of bronchospasm)
- Influenza A[1]
- Esophageal rupture
- Thoracic trauma
- Bowel rupture or other cause of air in abdominal cavity (tracts up into the chest)
- Mycoplasma pneumoniae pneumonia
- Environmental pulmonary barotrauma (e.g. scuba diving, flight)
- Iatrogenic - e.g. thoroscopy, VATS, bronchoscopy, colonoscopy or endoscopy
- Blast injury
Clinical Features
- Chest pain
- Dyspnea
- Voice change, cough, stridor
- Subcutaneous emphysema, especially of face, neck, and chest.[3]
- "Crunching" sound on auscultation during systole (Hamman's crunch)
- May mimic cardiac tamponade[4]
Differential Diagnosis
Chest pain
Critical
- Acute coronary syndromes (ACS)
- Aortic dissection
- Cardiac tamponade
- Coronary artery dissection
- Esophageal perforation (Boerhhaave's syndrome)
- Pulmonary embolism
- Tension pneumothorax
Emergent
- Cholecystitis
- Cocaine-associated chest pain
- Mediastinitis
- Myocardial rupture
- Myocarditis
- Pancreatitis
- Pericarditis
- Pneumothorax
Nonemergent
- Aortic stenosis
- Arthritis
- Asthma exacerbation
- Biliary colic
- Costochondritis
- Esophageal spasm
- Gastroesophageal reflux disease
- Herpes zoster / Postherpetic Neuralgia
- Hypertrophic cardiomyopathy
- Hyperventilation
- Mitral valve prolapse
- Panic attack
- Peptic ulcer disease
- Pleuritis
- Pneumomediastinum
- Pneumonia
- Rib fracture
- Stable angina
- Thoracic outlet syndrome
- Valvular heart disease
- Muscle sprain
- Psychologic / Somatic Chest Pain
- Spinal Root Compression
- Tumor
Thoracic Trauma
- Airway/Pulmonary
- Cardiac/Vascular
- Musculoskeletal
- Other
Diagnosis
- CXR
- AP/PA - Ring around right pulmonary artery, air along L heart border, air in upper chest/neck soft tissue
- Lateral - air along anterior heart border
- CT Chest
Management
- Supportive care[2]
- Pneumomediastinum typically reabsorbs over 1-2 weeks.
- Treat underlying cause, if identified
Disposition
- Depends on underlying cause and severity of condition
- Most patients with spontaneous pneumomediastinum without trauma or life-threatening condition (e.g. esophageal rupture or tension pneumothorax) can be safely discharged
See Also
External Links
References
- ↑ 1.0 1.1 Niehaus M, Rusgo A, Roth K, Jacoby JL. Retropharyngeal air and pneumomediastinum: a rare complication of influenza A and asthma in an adult. Am J Emerg Med. 2015 Jun 14. pii: S0735-6757(15)00495-7. doi: 10.1016/j.ajem.2015.06.020.
- ↑ 2.0 2.1 Johnson JN, Jones R, Wills BK. Spontaneous Pneumomediastinum. Western Journal of Emergency Medicine. 2008;9(4):217-218.
- ↑ Quresi SA, Tilyard A (2008). "Unusual Presentation of Spontaneous Mediastinum: A Case Report". Cases Journal 1:349. doi:10.1186/1757-1626-1-349
- ↑ Beg MH, Reyazuddin, Ansari MM (1988). "Traumatic tension Pneumomediastinum Mimicking Cardiac Tamponade". Thorax 43:576-677. doi: 10.1136/thx.43.7.576.