Pneumomediastinum: Difference between revisions

No edit summary
(16 intermediate revisions by 5 users not shown)
Line 1: Line 1:
==Background==
==Background==
*Also known as mediastinal emphysema
*Also known as mediastinal emphysema
*Definition: air present in the mediastinum
*Definition: presence of free air in the mediastinum
**Usually occurs with sudden increase in intra-alveolar pressure causing alveolar rupture, air dissects into pulmonary interstitium and then into mediastinum, neck, or pericardium
*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>
*Life threatening cause is [[esophageal rupture]]
*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>
*If no hemodynamic or airway compromise present, spontaneous pneumomediastinum is not a life threatening condition
*Life threatening causes include [[esophageal rupture]] or [[tension pneumothorax]]


===Causes===
===Causes===
*Illegal drug use
*Primary (spontaneous) pneumomediastinum
**Inhaling cocaine
**[[Asthma]]/[[COPD]] (Spontaneous or secondary to forceful coughing in the setting of bronchospasm) - most common co-morbidity<ref name="Bakhos" />
**Smoking cocaine
**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>
**Smoking marijuana
**[[Hydrocarbons|Hydrocarbon]] inhalation
*Vomiting
**[[Influenza]] A<ref name="Niehaus" />
*Retching
**Environmental [[pulmonary barotrauma]] (e.g. [[Scuba diving emergencies|scuba diving]], [[Commercial in-flight medical emergencies|flight]])
*Coughing
**Bowel rupture or other cause of air in abdominal cavity (tracts up into the chest)
*[[Asthma]]/[[COPD]]
**[[Mycoplasma pneumoniae]] [[pneumonia]]
*Esophageal rupture
**[[Esophageal rupture]] (rare)
*[[Thoracic trauma]]
*Secondary pneumomediastinum
**Search for other more serious injuries (larynx, bronchus, esophagus)
**Iatrogenic - e.g. thoracoscopy, VATS, bronchoscopy, colonoscopy or endoscopy
*Bowel rupture or other cause of air in abdominal cavity (tracts up into the chest)
**[[Blast injury]]
*[[Mycoplasma pneumoniae]] [[pneumonia]]
**[[Thoracic trauma]]
*Environmental [[barotrauma]] (e.g. [[Scuba diving emergencies|scuba diving]], [[Commercial in-flight medical emergencies|flight]])
*Iatrogenic (e.g. during thoroscopy/VATS) or endoscopy


==Clinical Features==
==Clinical Features==
*[[Chest pain]]
*[[Chest pain]]
*[[Dyspnea]]
*[[Dyspnea]]
*Voice change, cough, stridor
*[[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>  
*[[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)
*"Crunching" sound on auscultation during systole (Hamman's crunch)
*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>
*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>


==Differential Diagnosis==
==Differential Diagnosis==
Line 36: Line 34:
{{Thoracic trauma DDX}}
{{Thoracic trauma DDX}}


==Diagnosis==
==Evaluation==
[[File:PMC3047855 12245 2010 205 Fig1 HTML.png|thumb|Pneumomediastinum from nasal insufflation of cocaine.]]
[[File:PneumoMediastinum2008.jpg|thumb|Traumatic pneumomediastinum and right sided pneumothorax with first rib fracture.]]
[[File:PneumoMediastinum2008.jpg|thumb|Traumatic pneumomediastinum and right sided pneumothorax with first rib fracture.]]
[[File:Pneumomediastinum-003.jpg|thumb|Pneumomediastinum with Angel wing sign]]
[[File:Pneumomediastinum-003.jpg|thumb|Pneumomediastinum with Angel wing sign]]
*[[CXR]] or chest CT
[[File:Subcutaneous emphysema chest cropped.jpg|thumb|Pneumomediastinum with subcutanous emphysema on CT.]]
**AP/PA - Ring around right pulmonary artery, air along L heart border, air in upper chest/neck soft tissue
*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 - air along anterior heart border
*Rule-out esophageal rupture by hx and exam or with esophagoscopy if indicated
**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 patients with spontaneous pneumomediastinum, not caused by trauma or esophageal rupture, can 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==
Line 63: Line 69:
<references/>
<references/>


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

Revision as of 16:14, 17 September 2019

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

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.