AUTHOR AND EDITOR INFORMATION

Section 1 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

INTRODUCTION

Section 2 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Background

Mediastinitis is an infection involving the mediastinum. It is a surgical emergency with a high mortality rate. Mediastinitis may begin primarily from structures in the mediastinum, or it may be the result of an infection extending downward from the oropharynx, in which case it is called descending necrotizing mediastinitis.

The criteria for the diagnosis of descending necrotizing mediastinitis include the following:

• Clinical evidence of severe oropharyngeal infection
• Characteristic radiographic features of mediastinitis
• Documentation of necrotizing mediastinal infection at operation or at postmortem
• Establishment of the relationship between the descending necrotizing mediastinitis and the oropharyngeal infection

Pathophysiology

Infection of the mediastinum is typically polymicrobial in nature resulting from a disruption of normal mucosal and tissue barriers. Infection may result from a rupture of the esophagus or trachea or from surgical intervention. When infection extends from the head and neck downward into the mediastinum, the condition is described as descending necrotizing mediastinitis because the infection uses the fascial planes in the neck to gain access to the mediastinum. It is necrotizing, as the infection is often polymicrobial in etiology with gas-producing organisms. The potential spaces that can allow infections from the head or neck to enter the mediastinum include the following:

Carotid space

The carotid sheath is a thick, matted, fibrous investment over the main longitudinal vessels of the neck. Lymph nodes are contained within the sheath, and infection in these nodes potentially could spread downward into the mediastinum. The carotid sheath extends from the arch of the aorta to the base of the skull.

Prevertebral space

This space is bounded anteriorly by the prevertebral fascia, which overlies the prevertebral muscles in the neck. The prevertebral fascia extends from the base of the skull to the lower limit of the longus colli muscle, which is approximately at the level of T3 vertebra.

Danger space

This potential space lies between the alar and prevertebral fasciae. It is patent from the skull base to the diaphragm. Its upper part is the retropharyngeal space, which lies between the prevertebral fascia and the buccopharyngeal fascia on the outer surface of the pharynx. Lymph nodes are present in this space.

Pathological walling-off of infection usually occurs in the retropharyngeal space, but no anatomical barrier exists to the spread of infection downward into the mediastinum. The lower part of this potential space extends behind the esophagus, through the superior mediastinum, and into the posterior mediastinum.

More than 90% of cases of acute mediastinitis are caused by esophageal rupture. This may be due to trauma (eg, MVA, chicken bone), neoplasm, surgery, or endoscopy. See Esophageal Perforation, Rupture and Tears for more detail on this subject.

Comorbid conditions (eg, diabetes) may make certain patients highly susceptible to spreading cellulitis. Mediastinitis may also result from direct extension from an adjacent source of infection including osteomyelitis of the sternoclavicular junction. Pulmonary infections may also extend into the mediastinal space. Mediastinitis may also result from extension of granulomatous disease from mediastinal lymph nodes.

Pathogens

This is often a mixed infection, with facultative and strict aerobes acting together. Obligate anaerobes usually outnumber facultative organisms by 10:1. Streptococcus species are the most common facultative organisms, while Bacteroides species are the most common strict aerobes. Other organisms implicated include Pseudomonas aeruginosa and species of Fusobacterium, Peptostreptococcus, and Staphylococcus. Case reports have identified Eikenella corrodens and species of Prevotella, Haemophilus, and Salmonella as responsible pathogens. Histoplasmosis and tuberculosis have also been implicated in mediastinitis. As the incidence of iatrogenic mediastinitis rises compared with infections acquired outside the hospital, methicillin-resistant Staphylococcus aureus infections become a cause for great concern.

Candidal species and even aspergillus have been implicated in cases of meningitis.

Frequency

United States

Esophageal rupture is the most common cause of mediastinitis currently. Descending necrotizing infection is relatively rare in the era of antibiotic use.

International

In developing countries, mediastinitis still is a common devastating potential complication of head and neck infections.

Mortality/Morbidity

• Data suggest an overall mortality rate of 19-47%.
• In the presence of comorbid conditions, the mortality rate for patients presenting with established infections may be as high as 67%.
• Patients often require prolonged intensive care stay and long period of recovery.

Sex

Prevalence is higher among males than females, with a male-to-female ratio of 6:1.

Age

• Mediastinitis appears to be a disease of young men with a mean age in the mid fourth decade of life.
• Most persons with mediastinitis are in their third to fifth decades of life; however, case reports have documented mediastinitis in patients as young as 2 months and as old as the eighth decade.

CLINICAL

Section 3 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

History

Patients usually have experienced symptoms for a few days before presentation to the ED. Occasionally, patients present with a fulminant course and symptoms that have lasted only a few hours.

• Common symptoms and signs of patients with mediastinitis include the following:
• • History of an upper respiratory tract infection or a recent dental infection (common), or thoracic surgery/instrumentation 
  • Fever, chills
  • Pleuritic, retrosternal chest pain radiating to the neck or interscapular pain
  • Shortness of breath
  • Confusion
  • Sore throat
  • Swelling in the neck
• History may be significant for recent endoscopy, bronchoscopy, intubation, or surgery.
• Some patients are at an increased risk for mediastinitis. Obtaining the patient's medical history, which should include explicit questions about diabetes, possible immunocompromise (eg, malignancy/chemotherapy, HIV, autoimmune disease), and drug abuse, is very important.

Physical

A complete examination of the head and neck, including the oral cavity, is essential. Such an examination may yield findings such as the following:

• Ill appearance
• Fever
• Edema of the neck and face
• Crepitus of chest or neck

Causes

• Pharyngitis
• Tonsillitis
• Sinusitis
• Otitis media
• Dental infections
• Sialadenitis
• Suppurative thyroiditis
• Endotracheal intubation  
• • Perforation of the hypopharynx or esophagus during intubation may cause mediastinitis.
  • This is particularly likely to occur if the intubation was difficult and required the use of a rigid stylet.
  • Patients usually develop symptoms and signs in the immediate postintubation period, although delayed presentations are reported. Consider this complication if a patient's condition deteriorates in the postintubation period and if signs of sepsis or cardiovascular compromise are observed.
• Fibrosing mediastinitis  
• • This very rare entity is an excessive fibrotic reaction in the mediastinum. It is usually observed as a result of histoplasmosis or other granulomatous disease.
  • Patients usually present with symptoms of compression or occlusion of mediastinal structures.
  • Presenting symptoms include cough, superior vena caval obstruction, shortness of breath, chest pain, or hemoptysis.
  • The onset is usually insidious.
• Other causes  
• • Tuberculous mediastinitis may occur after the rupture of a tuberculous lymph node into the mediastinum. The diagnosis may be difficult to make because some patients initially may have few symptoms or signs. Radiographic findings may indicate a mediastinal mass, and the diagnosis may not be made until further investigations, including an MRI, are completed.
  • Mediastinitis may present as a delayed nosocomial infection following coronary artery bypass surgery.
  • Fungal infection, usually caused by Candida species, is observed after cardiothoracic surgery in 0.3% of cases.
  • Iatrogenic mishap following endoscopy or endoscopic ultrasonographic-guided transesophageal biopsy may be a cause.
  • Ingestion of a sharp object and esophageal perforation may be a cause.
  • Recently, mediastinitis has been described as a complication of laparoscopic cholecystectomy.

DIFFERENTIALS

Section 4 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Other Problems to be Considered

Ludwig angina

WORKUP

Section 5 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Lab Studies

• The diagnosis of mediastinitis is often a clinical one. No single laboratory investigation can confirm the diagnosis; however, studies that may help in the diagnosis of mediastinitis include the following:
• • WBC count may be significantly elevated.
  • Electrolytes and glucose measurements may reveal anion gap or indication of underlying diabetes.
  • Blood cultures
  • Swab from any site of infection
• It is important to notify the laboratory of the possible presence of anaerobic organisms and the strong possibility of mixed growth.
• • Many laboratories routinely report only a single predominant organism.
  • Close coordination with the laboratory is vital to optimize the antibiotic regimen.

Imaging Studies

• Plain-film radiography  
• • Soft tissue radiography of the neck may show widening of the precervical and retropharyngeal soft tissues.
  • Any patient who presents with gas in the soft tissues of the neck and concern for possible mediastinitis probably should undergo further investigation (ie, CT, MRI) to determine if mediastinal spread of the infection has occurred.
  • Plain-film chest radiographs may show widening of the paratracheal soft tissues.
  • The lateral chest radiograph may show an anterior bulge on the posterior wall of the trachea.
  • Pleural effusions and lower lobe consolidation are not unusual findings.
• Head CT  
• • The head CT scan may demonstrate abnormalities while the chest radiograph still appears normal.
  • Abscess and soft tissue swelling are usually visible.
  • Repeated head CTs are essential to follow the progress of therapy.
• Chest CT: Chest CT should be rapidly performed in the ED and may help to determine the mode of surgical approach for drainage. Chest CT can also be used to follow the course of treatment in patients who are not surgically drained.
• Neck CT  
• • Neck CT documents the path of descending infections.
  • It may be used to plan an operative approach for surgical drainage.
• MRI: Use of MRI to confirm the diagnosis of mediastinitis is becoming more frequent.

TREATMENT

Section 6 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Prehospital Care

Mediastinitis may result in airway compromise. Protection of the airway is vital. Since patients may present in septic shock, adequate volume resuscitation is essential.

Emergency Department Care

• Ensure an adequate airway.
• • Do not allow a patient who is potentially unstable to be placed into the CT scanner without ensuring that the airway is adequately protected.
  • Intubation may be difficult because of soft tissue swelling. Fiberoptic assistance may be required and the patient may need an emergent cricothyrotomy or tracheostomy.
  • In addition to the usual complications of intubation, it may be further complicated by trauma to the retropharyngeal wall, laryngospasm, or aspiration of purulent material.
• Antibiotic therapy should be initiated without delay.
• Fluid resuscitation and management of sepsis are essential.

Consultations

• Immediately make arrangements for surgical consultation.
• • Extensive and aggressive debridement of necrotic tissues with exploration of all mediastinal fascial spaces may be required.
  • Controversy exists about whether the cervical approach or the transthoracic approach is best. Some physicians support a combination of the two approaches. In some case series, the combination approach has been associated with a lower mortality rate.
  • Depending upon the resources available, consultations may include otorhinolaryngology, cardiothoracic surgery, and general surgery.
• The necessity for extensive drainage may mandate the transfer of some patients to a tertiary referral center.

MEDICATION

Section 7 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Because mediastinitis usually is a mixed growth infection, wide antimicrobial coverage is required. The cause of infection should be determined. Extension of a Staphylococcus aureus osteomyelitis should be managed differently from an esophageal rupture; however, in the absence of a source and definitive microbiological data, broad-spectrum therapy is indicated. Combinations such as piperacillin-tazobactam with vancomycin or ceftazidime with vancomycin or vancomycin with a fluoroquinolone and clindamycin should be used. An aminoglycoside may be added to broaden gram-negative coverage.

Drug Category: Antibiotics

Therapy must cover all likely pathogens in the context of the clinical setting.

FOLLOW-UP

Section 8 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Further Inpatient Care

• As for any abscess, the essential management of this condition involves extensive surgical debridement.
• The use of hyperbaric oxygen for this condition is controversial.
• Recent studies have looked at the use of intravenous immunoglobulins for mediastinitis, particularly when the condition arises as a complication of cardiothoracic surgery.
• Broad-spectrum antibiotics are necessary. Antibiotics should be capable of treating aerobes, anaerobes, and gram-positive and gram-negative infection.

Transfer

• Optimal treatment of this disease requires extensive surgical debridement. This may require the services of cardiothoracic surgeons and otorhinolaryngologists and may necessitate a transfer if these services are not available.
• These patients often require highly skilled intensive care. Some patients may require referral to a tertiary care center if these resources are not available at the presenting hospital.

Complications

• Pericarditis
• Sepsis
• Multiorgan system failure

Prognosis

• This condition, once established, has a high mortality rate (up to 50%), despite intensive care management.
• Early diagnosis and aggressive therapy seem to provide the best chance for recovery.

MISCELLANEOUS

Section 9 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Medical/Legal Pitfalls

• Consider the possibility of mediastinitis if evidence indicates that gas is present in the soft tissues of the neck.
• Consider a diagnosis of mediastinitis in patients with upper respiratory tract infections who present with signs or symptoms that appear to be out of proportion to the initial findings.

Special Concerns

• If a patient has had recent cardiothoracic surgery, be sure to consider the possibility of a fungal etiology. Send blood for fungal cultures.
• Most recommendations for therapy are based on retrospective case series, literature reviews, and personal experience.

ACKNOWLEDGMENTS

Section 10 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

The authors and editors of eMedicine gratefully acknowledge the contributions of previous author, Martin J Carey, MD, to the development and writing of this article.

MULTIMEDIA

Section 11 of 12  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

Media file 1:  Chest radiograph of a patient presenting with mediastinitis secondary to esophageal perforation by a chicken bone. Image courtesy of Mark Silverberg, MD, FACEP, and Rafi Israeli, MD.
	View Full Size Image
Media type:  Radiograph

Media file 2:  Chest CT of same patient showing gas-filled mediastinal abscess and widened esophagus. Image courtesy of Mark Silverberg, MD, FACEP, and Rafi Israeli, MD.
	View Full Size Image
Media type:  CT

REFERENCES

Section 12 of 12

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Acknowledgments
• Multimedia
• References

• Akman C, Kantarci F, Cetinkaya S. Imaging in mediastinitis: a systematic review based on aetiology. Clin Radiol. Jul 2004;59(7):573-85. [Medline].
• Becker M, Zbaren P, Hermans R, Becker CD, Marchal F, Kurt AM, et al. Necrotizing fasciitis of the head and neck: role of CT in diagnosis and management. Radiology. Feb 1997;202(2):471-6. [Medline].
• Brook I, Frazier EH. Microbiology of mediastinitis. Arch Intern Med. Feb 12 1996;156(3):333-6. [Medline].
• Brunelli A, Sabbatini A, Catalini G, Fianchini A. Descending necrotizing mediastinitis. Surgical drainage and tracheostomy. Arch Otolaryngol Head Neck Surg. Dec 1996;122(12):1326-9. [Medline].
• Bulut M, Balci V, Akkose S, Armagan E. Fatal descending necrotising mediastinitis. Emerg Med J. Jan 2004;21(1):122-3. [Medline].
• Clancy CJ, Nguyen MH, Morris AJ. Candidal mediastinitis: an emerging clinical entity. Clin Infect Dis. Sep 1997;25(3):608-13. [Medline].
• Corsten MJ, Shamji FM, Odell PF, Frederico JA, Laframboise GG, Reid KR, et al. Optimal treatment of descending necrotising mediastinitis. Thorax. Aug 1997;52(8):702-8. [Medline].
• Gamlin F, Caldicott LD, Shah MV. Mediastinitis and sepsis syndrome following intubation. Anaesthesia. Oct 1994;49(10):883-5. [Medline].
• Haraden BM, Zwemer FL Jr. Descending necrotizing mediastinitis: complication of a simple dental infection. Ann Emerg Med. May 1997;29(5):683-6. [Medline].
• Isaacs LM, Kotton B, Peralta MM Jr, Shekar R, Meden G, Brown LA, et al. Fatal mediastinal abscess from upper respiratory infection. Ear Nose Throat J. Sep 1993;72(9):620-2, 624-6, 631. [Medline].
• Kiernan PD, Hernandez A, Byrne WD, Bloom R, Dicicco B, Hetrick V, et al. Descending cervical mediastinitis. Ann Thorac Surg. May 1998;65(5):1483-8. [Medline].
• Marty-Ané CH, Berthet JP, Alric P, Pegis JD, Rouvière P, Mary H. Management of descending necrotizing mediastinitis: an aggressive treatment for an aggressive disease. Ann Thorac Surg. Jul 1999;68(1):212-7. [Medline].
• Marty-Ane CH, Alauzen M, Alric P, Serres-Cousine O, Mary H. Descending necrotizing mediastinitis. Advantage of mediastinal drainage with thoracotomy. J Thorac Cardiovasc Surg. Jan 1994;107(1):55-61. [Medline].
• Mathisen DJ, Grillo HC. Clinical manifestation of mediastinal fibrosis and histoplasmosis. Ann Thorac Surg. Dec 1992;54(6):1053-7; discussion 1057-8. [Medline].
• Nielsen TR, Clement F, Andreassen UK. Mediastinitis-a rare complication of a peritonsillar abscess. J Laryngol Otol. Feb 1996;110(2):175-6. [Medline].
• Nomori H, Horio H, Kobayashi R. Descending necrotizing mediastinitis secondary to pharyngitis. A case report. Scand Cardiovasc J. 1997;31(4):233-5. [Medline].
• Pasaoglu I, Arsan S, Yorgancioglu AC, Yüksel Bozer A. A simple management of mediastinitis. Int Surg. Jul-Sep 1995;80(3):239-41. [Medline].
• Sugata T, Fujita Y, Myoken Y, Fujioka Y. Cervical cellulitis with mediastinitis from an odontogenic infection complicated by diabetes mellitus: report of a case. J Oral Maxillofac Surg. Aug 1997;55(8):864-9. [Medline].
• Watanabe M, Ohshika Y, Aoki T, Takagi K, Tanaka S, Ogata T. Empyema and mediastinitis complicating retropharyngeal abscess. Thorax. Nov 1994;49(11):1179-80. [Medline].
• Iwama S, Kato Y, Nakayama S. Acute suppurative thyroiditis extending to descending necrotizing mediastinitis and pericarditis. Thyroid. Mar 2007;17(3):281-2. [Medline].
• Misthos P, Katsaragakis S, Kakaris S, Theodorou D, Skottis I. Descending necrotizing anterior mediastinitis: analysis of survival and surgical treatment modalities. J Oral Maxillofac Surg. Apr 2007;65(4):635-9. [Medline].
• Kaira K, Yasuoka H, Ichikawa T, Oh-I S, Hisada T, Ishizuka T, et al. Descending necrotizing mediastinitis after upper gastrointestinal endoscopy. Endoscopy. Feb 2007;39 Suppl 1:E29. [Medline].
• Allotey J, Duncan H, Williams H. Mediastinitis and retropharyngeal abscess following delayed diagnosis of glass ingestion. Emerg Med J. Feb 2006;23(2):e12. [Medline].
• Reddy SL, Grayson AD, Smith G, Warwick R, Chalmers JA. Methicillin resistant Staphylococcus aureus infections following cardiac surgery: incidence, impact and identifying adverse outcome traits. Eur J Cardiothorac Surg. Jul 2007;32(1):113-7. [Medline].
• Diez C, Koch D, Kuss O, Silber RE, Friedrich I, Boergermann J. Risk factors for mediastinitis after cardiac surgery - a retrospective analysis of 1700 patients. J Cardiothorac Surg. 2007;2:23. [Medline].
• Savides TJ, Margolis D, Richman KM, Singh V. Gemella morbillorum mediastinitis and osteomyelitis following transesophageal endoscopic ultrasound-guided fine-needle aspiration of a posterior mediastinal lymph node. Endoscopy. Feb 2007;39 Suppl 1:E123-4. [Medline].
• Scaglione M, Pinto A, Giovine S, Di Nuzzo L, Giuliano V, Romano L. CT features of descending necrotizing mediastinitis--a pictorial essay. Emerg Radiol. Jun 2007;14(2):77-81. [Medline].

Article Last Updated: Apr 2, 2008