Pneumomediastinum: Difference between revisions
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==Background==
==Background==
*usually occurs with sudden increase in intra-alveolar pressure causing alveolar rupture, air dissects into pulmonary interstitium and then into mediastinum, neck, or pericardium
*Also known as mediastinal emphysema
*life threatening cause is [[Esophageal Perforation|esophageal rupture]]
*Definition: presence of free air in the mediastinum
*if no hemodynamic or airway compromise present, spontaneous pneumomediastinum is not a life threatening condition 
*Can be Spontaneous or secondary (to violation of aerodigestive tract)<ref name="Bakhos">Bakhos CT, Pupovac SS, Ata A, et al. Spontaneous pneumomediastinum: an extensive workup is not required. J Am Coll Surg. 2014 Oct;219(4):713-7. doi: 10.1016/j.jamcollsurg.2014.06.001.</ref>
*Spontaneous pneumomediastinum 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<ref name="Niehaus">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.</ref>
*Life threatening causes include [[esophageal rupture]] or [[tension pneumothorax]]


==Causes==
===Causes===
*illegal drug use
*Primary (spontaneous) pneumomediastinum
**[[Asthma]]/[[COPD]] (Spontaneous or secondary to forceful coughing in the setting of bronchospasm) - most common co-morbidity<ref name="Bakhos" />
**Recreational drug use (via inhalation) - cocaine, methamphetamine, marijuana<ref name="Johnson">Johnson JN, Jones R, Wills BK. Spontaneous Pneumomediastinum. Western Journal of Emergency Medicine. 2008;9(4):217-218.</ref>
**Hydrocarbon inhalation
**Influenza A<ref name="Niehaus" />
**Environmental [[pulmonary barotrauma]] (e.g. [[Scuba diving emergencies|scuba diving]], [[Commercial in-flight medical emergencies|flight]])
**Bowel rupture or other cause of air in abdominal cavity (tracts up into the chest)
**[[Mycoplasma pneumoniae]] [[pneumonia]]
**[[Esophageal rupture]] (rare)
*Secondary pneumomediastinum
**Iatrogenic - e.g. thoroscopy, VATS, bronchoscopy, colonoscopy or endoscopy
**Blast injury
**[[Thoracic trauma]]


#inhaling cocaine
==Clinical Features==
#smoking cocaine
*[[Chest pain]]
#smoking marijuana
*[[Dyspnea]]
*[[Subcutaneous emphysema]], especially of face, neck, and chest.<ref>Quresi SA, Tilyard A (2008). "Unusual Presentation of Spontaneous Mediastinum: A Case Report". ''Cases Journal'' 1:349. doi:10.1186/1757-1626-1-349</ref>
*Voice change, cough, stridor
*"Crunching" sound on auscultation during systole (Hamman's crunch)
*Severe cases (generally after trauma) may mimic [[cardiac tamponade]]<ref>Beg MH, Reyazuddin, Ansari MM (1988). "Traumatic tension Pneumomediastinum Mimicking Cardiac Tamponade".  ''Thorax'' 43:576-677. doi: 10.1136/thx.43.7.576.</ref><ref>Jennings S, Peeceeyen S, Horton M. Tension pneumomediastinum after blunt chest trauma. ANZ J Surg. 2015 Jan;85(1-2):90-1. doi: 10.1111/ans.12378.</ref>


*vomiting
==Differential Diagnosis==
*retching
{{Template:Chest Pain DDX}}
*asthma
*coughing
*esophageal rupture
*recent endoscopy
*trauma
**Search for other more serious injuries (larynx, bronchus, esophagus)


==Clinical Features==
{{Thoracic trauma DDX}}
*chest pain
**voice change, cough, stridor
*subQ&nbsp;emphysema in chest wall, neck, face, abdomen, scrotum
*"Hamman's Crunch" - crunching sound of heart during systole


==Workup==
==Evaluation==
*ABCs
[[File:PMC3047855 12245 2010 205 Fig1 HTML.png|thumb|Pneumomediastinum from nasal insufflation of cocaine.]]
*CXR
[[File:PneumoMediastinum2008.jpg|thumb|Traumatic pneumomediastinum and right sided pneumothorax with first rib fracture.]]
*Rule-out esophageal rupture by hx and exam or with esophagoscopy if indicated
[[File:Pneumomediastinum-003.jpg|thumb|Pneumomediastinum with Angel wing sign]]
[[File:Subcutaneous emphysema chest cropped.jpg|thumb|Pneumomediastinum with subcutanous emphysema on CT.]]
*CT Chest (preferred diagnostic test)
*[[CXR]]
**AP/PA - Ring around right pulmonary artery, air along left heart border, air in upper chest/neck soft tissue
**Lateral - air along anterior heart border
**Lateral neck - may see mediastinal air in neck
**30% with spontaneous pneumomediastinum will have normal CXR<ref name="Bakhos" />


==Management==
==Management==
*supportive
*Supportive care<ref name="Johnson" />
*no specific therapy for spontaneous pneumomediastinum
**Pneumomediastinum typically reabsorbs over 1-2 weeks.
*treat underlying cause
*Treat underlying cause, if identified


==Disposition==
==Disposition==
*depends on underlying cause and severity of condition
*Spontaneous pneumomediastinum
*most pt's with spontaneous pneumomediastinum, not caused by trauma or&nbsp;esophageal rupture, can&nbsp;be safely discharged
**Benign and self-limited disease
**Generally does not require repeat imaging, and can be managed conservatively on an outpatient basis<ref name="Bakhos" /><ref>Fitzwater JW, Silva NN, Knight CG, et al. Management of spontaneous pneumomediastinum in children. J Pediatr Surg. 2015 Jun;50(6):983-6. doi: 10.1016/j.jpedsurg.2015.03.024.</ref><ref>Smith BA, Ferguson DB. Disposition of spontaneous pneumomediastinum. Am J Emerg Med. 1991 May;9(3):256-9.</ref>
*Secondary pneumomediastinum<ref>de Virgilio C, Kim DY. Pneumomediastinum Following Blunt Trauma: Are We Closer to Unlocking Its Significance? JAMA Surg. 2015 Jun 24. doi: 10.1001/jamasurg.2015.1146.</ref>
**Most cases are benign, but a minority of cases require additional testing and intervention.
**Have lower threshold for additional testing and admission.


==See Also==
==See Also==
*[[Pneumothorax (main)]]
*[[Thoracic Trauma]]
*[[Thoracic Trauma]]
*[[Mediastinitis]]
*[[Mediastinitis]]


==Sources==
==External Links==
Harwood-Nuss, Rosens
 
==References==
<references/>


[[Category:Pulm]]
[[Category:Pulmonary]]

Revision as of 05:59, 22 May 2017

Background

  • Also known as mediastinal emphysema
  • Definition: presence of free air in the mediastinum
  • Can be Spontaneous or secondary (to violation of aerodigestive tract)[1]
  • Spontaneous pneumomediastinum 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[2]
  • Life threatening causes include esophageal rupture or tension pneumothorax

Causes

  • Primary (spontaneous) pneumomediastinum
  • Secondary pneumomediastinum
    • Iatrogenic - e.g. thoroscopy, VATS, bronchoscopy, colonoscopy or endoscopy
    • Blast injury
    • Thoracic trauma

Clinical Features

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Thoracic Trauma

Evaluation

Pneumomediastinum from nasal insufflation of cocaine.
Traumatic pneumomediastinum and right sided pneumothorax with first rib fracture.
Pneumomediastinum with Angel wing sign
Pneumomediastinum with subcutanous emphysema on CT.
  • CT Chest (preferred diagnostic test)
  • CXR
    • AP/PA - Ring around right pulmonary artery, air along left heart border, air in upper chest/neck soft tissue
    • Lateral - air along anterior heart border
    • Lateral neck - may see mediastinal air in neck
    • 30% with spontaneous pneumomediastinum will have normal CXR[1]

Management

  • Supportive care[3]
    • Pneumomediastinum typically reabsorbs over 1-2 weeks.
  • Treat underlying cause, if identified

Disposition

  • Spontaneous pneumomediastinum
    • Benign and self-limited disease
    • Generally does not require repeat imaging, and can be managed conservatively on an outpatient basis[1][7][8]
  • Secondary pneumomediastinum[9]
    • Most cases are benign, but a minority of cases require additional testing and intervention.
    • Have lower threshold for additional testing and admission.

See Also

External Links

References

  1. ↑ 1.0 1.1 1.2 1.3 Bakhos CT, Pupovac SS, Ata A, et al. Spontaneous pneumomediastinum: an extensive workup is not required. J Am Coll Surg. 2014 Oct;219(4):713-7. doi: 10.1016/j.jamcollsurg.2014.06.001.
  2. ↑ 2.0 2.1 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.
  3. ↑ 3.0 3.1 Johnson JN, Jones R, Wills BK. Spontaneous Pneumomediastinum. Western Journal of Emergency Medicine. 2008;9(4):217-218.
  4. ↑ Quresi SA, Tilyard A (2008). "Unusual Presentation of Spontaneous Mediastinum: A Case Report". Cases Journal 1:349. doi:10.1186/1757-1626-1-349
  5. ↑ Beg MH, Reyazuddin, Ansari MM (1988). "Traumatic tension Pneumomediastinum Mimicking Cardiac Tamponade". Thorax 43:576-677. doi: 10.1136/thx.43.7.576.
  6. ↑ Jennings S, Peeceeyen S, Horton M. Tension pneumomediastinum after blunt chest trauma. ANZ J Surg. 2015 Jan;85(1-2):90-1. doi: 10.1111/ans.12378.
  7. ↑ Fitzwater JW, Silva NN, Knight CG, et al. Management of spontaneous pneumomediastinum in children. J Pediatr Surg. 2015 Jun;50(6):983-6. doi: 10.1016/j.jpedsurg.2015.03.024.
  8. ↑ Smith BA, Ferguson DB. Disposition of spontaneous pneumomediastinum. Am J Emerg Med. 1991 May;9(3):256-9.
  9. ↑ de Virgilio C, Kim DY. Pneumomediastinum Following Blunt Trauma: Are We Closer to Unlocking Its Significance? JAMA Surg. 2015 Jun 24. doi: 10.1001/jamasurg.2015.1146.
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