Mediastinitis describes an inflammation of the mediastinum and can occur after an injury or the spread of an infection from adjacent structures in the head and neck. It is a medical emergency that requires immediate treatment.
Presentation
Patients with mediastinitis usually report a recent upper respiratory tract infection, surgery in the thorax, infection of the teeth, pain with swallowing, altered mental status, dyspnea, sore throat and shortness of breath [8].
Symptoms of mediastinitis usually start a few days before the patient presents to the emergency department. Nonetheless, in selective cases, the symptoms may appear suddenly and last only a few hours.
History is very important in establishing a diagnosis for the condition. Relevant history includes a recent bronchoscopy, endoscopy, cancer in the thorax or ingestion of a chicken or a fish bone.
Sudden development of mediastinitis may indicate a history of drug abuse in patients who cannot recall that they have vomited forcefully or among children who possibly ingested a harmful substance.
Chronic diseases such as diabetes, autoimmune diseases and chemotherapy may also predispose for mediastinitis. In addition, patients with a history of drug abuse are at an increased risk.
Entire Body System
- Wound Infection
Deep sternal wound infection Deep sternal wound infection is a process in which the mediastinum becomes infected due to a deep wound infection after sternotomy, which is used primarily in heart surgery. [news-medical.net]
Patients with a mediastinal infection secondary to an infected median sternotomy wound may have signs of wound infection on examination 2. [radiopaedia.org]
Negative pressure wound therapy has revolutionised the ward-based management of deep sternal wound infections. [cardiothoracicsurgery.biomedcentral.com]
They comprise sternal dehiscence, deep sternal wound infections and mediastinitis, which will be treated as varying expressions of a singular pathology for reasons explained in the text. [ncbi.nlm.nih.gov]
- Fatigue
If patients are symptomatic, the most common complaints are fever, sore throat, fatigue, and enlarged lymph nodes. [jcm.asm.org]
The patient has been feeling more fatigued and tired for last few months. On admission, vitals were normal. On physical examination, he was anxious and appeared to be in distress, rest of the systemic examination was unremarkable. [cureus.com]
Most patients recover without treatment, but some of them remain dyspneic and fatigued for months. Conversely, chronic pulmonary histoplasmosis follows exposure in patients with underlying lung diseases. [hindawi.com]
The following day, he started to feel fatigued with fevers, anorexia, odynophagia, and nausea but denied vomiting. His medical history included hypertension and he had no surgical history. He had recent prolonged traveling. [journals.lww.com]
Patients may present with shortness of breath (dyspnea), fatigue or loss of stamina, cough with blood (hemoptysis) or without, chronic chest (pleuritic) pain, recurrent pulmonary infections or pneumonias, difficulty swallowing (dysphagia), or swelling [rarediseases.org]
- Intravenous Administration
Despite the drainage of the submandibular abscess, the extractions of first and second mandibular molars and the intravenous administration of antibiotics, the patient remained systemically unwell and the swelling extended to the anterior neck. [nature.com]
Even with a rapid intravenous administration of broad-spectrum antimicrobial agents, death is likely without immediate and comprehensive surgical treatment. [journals.sagepub.com]
The prophylactic antibiotic regimen in both centers included the intravenous administration of 2 g Cefotiam one hour preoperatively and six hours postoperatively. [cardiothoracicsurgery.biomedcentral.com]
However, MR imaging performed with flow-sensitive pulse sequences can be useful for assessment of vascular stenoses in patients for whom intravenous administration of contrast material is contraindicated (,47,,57). [pubs.rsna.org]
- Multiple Organ Dysfunction Syndrome
Complications Complications of DNM were recorded in 12 patients (70.6%) and included multiple organ dysfunction syndrome (MODS) in 6 (35%), of whom 5 initially presented in a state of septic shock. [doi.org]
- Candidiasis
As possible local predisposing factors, in terms of site of entry of infection, one patient suffered from chronic tonsillitis and severe oral candidiasis and another from an intubation injury of the larynx that occurred 4 weeks previously. [doi.org]
Respiratoric
- Stridor
Given lack of stridor, shortness of breath, or inability to tolerate secretions, there was no immediate concern for airway compromise. [hindawi.com]
Symptoms commonly referred to are fever, pain and sepsis; cranial nerve deficits are common, as is trismus and stridor; erosion into adjacent hypopharynx, oesophagus or vascular structures may occur. [academic.oup.com]
Stridor ( n = 1), swelling of the face ( n = 1), thoracic pain ( n = 1) and shoulder pain ( n = 1) were rarely reported. The main clinical findings were fever in all patients and swelling/redness of the pharynx/larynx ( n = 14, 82%). [doi.org]
Idiopathic fibrosing mediastinitis in a 38-year-old man with intermittent stridor. Linear tomogram shows diffuse narrowing of the trachea and both main bronchi and a soft-tissue mass encasing the distal trachea. Figure 13a. [pubs.rsna.org]
- Tracheal Deviation
View Figure 2 Figure 3: Disease progression seen on PA chest X-ray with tracheal deviation. View Figure 3 Figure 4: PA chest x-ray showing complete destruction of right lung and progressive fibrosis of left lung. [clinmedjournals.org]
Later, tracheal deviation, jugular venous distention, and other signs of compression of mediastinal structures may appear. 5. [de.slideshare.net]
Conventional thoracic radiography can highlight the indirect signs of mediastinitis such as subcutaneous emphysema, lateral or anterior tracheal deviation, and pleural fluid collections [4, 31]. [content.sciendo.com]
Gastrointestinal
- Abdominal Pain
He denied smoking, drinking alcohol, excessive caffeine consumption, substance use, recent travel, cough, fever, chills, night sweats, hemoptysis, weight loss, joint pain, rash, nausea, vomiting, abdominal pain and syncopal episodes. [cureus.com]
Cardiovascular
- Hypotension
He had high fever, chest pain with tachypnea, tachycardia, hypotension, and showed signs of occasional disorientation. [ncbi.nlm.nih.gov]
[…] obtained if mediastinitis is suspected findings mediastinal gas and fluid Differential Acute pericarditis distinguishing factor may present with pleuritic chest pain and a friction rub Cardiac tamponade distinguishing factor may present with Beck triad (hypotension [step2.medbullets.com]
[…] diabetes mellitus immunosuppression factors which could contribute to increased postoperative complications, such as 2,3: advanced age obesity smoking Patients may experience retrosternal pain and exhibit systemic signs such as fever, tachycardia or hypotension [radiopaedia.org]
Patients may present with hypotension and clinical signs of sepsis (rare with empyema alone). Chest radiographs will demonstrate a pleural effusion, pneumomediastinum or an enlarged cardiac silhouette (pericarditis). [cancertherapyadvisor.com]
- Retrosternal Chest Pain
Symptoms: 1) Acute mediastinitis presents as severe retrosternal chest pain that intensifies with breathing or coughing; tenderness around the sternum and sternocostal joints; symptoms of pneumomediastinum and subcutaneous emphysema; and symptoms of inflammation [empendium.com]
Retrosternal chest pain, usually described as pleuritic, may radiate to the neck or back. There may be a sensation of soreness or congestion in the neck if the condition is due to descending infection. [patient.info]
Face, Head & Neck
- Subcutaneous Emphysema of the Neck
The first imaging test is a posteroanterior and lateral thoracic X-ray, in which we find radiological signs which may guide us: widening of the mediastinum, pneumomediastinum and subcutaneous emphysema of the neck associated with pneumothorax and pleural [posterng.netkey.at]
Urogenital
- Kidney Failure
In limited cases, complications can arise, including rupture of the spleen, myocarditis, pancreatitis, acute kidney failure, or neurological disorders ( 1 ). [jcm.asm.org]
Kidney failure. Obesity. Peripheral artery disease (PAD). Smoking and tobacco use also raise your risk of post-surgery complications. [my.clevelandclinic.org]
These triggering conditions are more aggressive if associated with factors such as age, smoking, chronic pulmonary disease, diabetes mellitus, chronic kidney failure, immunosuppression treatment with corticosteroids, and generalised atherosclerosis [12 [content.sciendo.com]
Workup
Mediastinitis can be diagnosed clinically based on history and clinical presentation. A computed tomography (CT scan) or a chest x-ray can also confirm the diagnosis [9].
Patients with a history of thoracic surgery may undergo a needle aspiration biopsy; a procedure in which a needle is inserted through the sternum to retrieve fluid that can be sent for culture and examination under a microscope.
X-Ray
- Atelectasis
Hydropneurnothorax 3 Hydrothorax 4 Hemothorax 5 Chylothorax 388 Tumors of the pleura 389 PART III 203 Diseases of the Lungs 205 Haemoptysis 216 DISEASES OF THE PERICARDIUM 245 Alveolar emphysema of the lungs 3 Interlobular emphysema of the lungs 257 Pulmonary atelectasis [books.google.dk]
Chest x-rays generally demonstrate the following: [1] [2] [3] Calcification ( mediastinal and/or hilar ) Widening of the mediastinum (especially on the right side) Increased right hilar bronchovascular bundles Enlargement of the right paratracheal area Atelectasis [wikidoc.org]
Hamman-Rich syndrome · Interstitial lung disease Suppurative and necrotic conditions of lower respiratory tract Lung abscess · Pleural effusion · Empyema Other Pneumothorax · Hemothorax · Hemopneumothorax · Mendelson's syndrome · Respiratory failure · Atelectasis [bionity.com]
Computed tomography (CT) of the chest revealed right-sided hydropneumothorax with adjacent crescent atelectasis, patchy bilateral airspace consolidation, fluid collections throughout the anterior and superior mediastinum and extending to the base of the [pubs.sciepub.com]
Serum
- Hyponatremia
Tolvaptan may be useful for correcting hyponatremia and volume overload in patients under LVAD support. [ncbi.nlm.nih.gov]
Metabolic measurements are often normal but may reveal anion gap, hyponatremia, hypoglycemia or hyperglycemia, or hypoproteinemia Blood cultures Swab from any site of infection It is important to notify the laboratory of the possible presence of anaerobic [emedicine.medscape.com]
Fungi Candida albicans Paraclinical diagnosis is not specific for acute mediastinitis, since it determines leukocytosis, respectively increased inflammatory markers (C-reactive protein, VSH, procalcitonin), which can cause blood sugar imbalances and hyponatremia [content.sciendo.com]
Microbiology
- Eikenella
Case reports have also identified Eikenella corrodens and species of Prevotella, Stenotrophomonas, Propionibacterium, Candida, Aspergillus, and Salmonella as responsible pathogens. [3, 5] As the incidence of iatrogenic mediastinitis rises compared with [emedicine.medscape.com]
Peptostreptococcus Actinomyces Lactobacillus Eubacterium Veillonella Bacteroides Prevotella Porphyromonas Fusobacterium Aerobic Streptococci (including beta-hemolytic and S. viridans group), Staphylococci Corynebacterium Moraxella Enterobacteriaceae Eikenella [content.sciendo.com]
Gram-positive cocci – Streptococci (including beta-hemolytic and S. viridans group), Staphylococci Fungi – Candida albicans (unusual) Gram-positive bacilli – Corynebacterium Gram-negative cocci – Moraxella Gram-negative bacilli – Enterobacteriaceae, Eikenella [infectiousdiseaseadvisor.com]
- Gram-Positive Rods
Bacteriology cultures showed gram-positive anaerobic cocci and rods and Staphylococcus haemolyticus. Consequently, vancomycin, to which the organisms are sensitive, was prescribed in place of neomycin. [ncbi.nlm.nih.gov]
Streptococcus milleri Bacteroides melaninogenicus Enterobacter spp.,* Pseudomonas aeruginosa 5 Staphylococcus epidermidis* Bacteroides intermedius Streptococci Enterobacter spp., Escherichia coli Pseudomonas aeruginosa 6 Staphylococcus epidermidis* Anaerobic gram-positive [jtcvs.org]
Treatment
Protection of the respiratory airway is one of the most important initial goals of treatment. The patient should not be placed in the CT scanner if the airway has not been secured. Unfortunately, swelling in the soft tissue can impede airway protection and may require fiber-optic aid. Intubation can also be further complicated by laryngospasm, trauma to the retropharyngeal wall or aspiration of pus. Urgent cricothyrotomy or tracheostomy are other options in case of severe complications.
Septic shock is common and patients require extensive fluid resuscitation upon presentation, in addition to antibiotic administration and the enforcement of sepsis protocols.
The most important part of management in the emergency setting is the prompt diagnosis. The latter can considerably improve outcomes. The differential diagnosis of mediastinitis is broad and clinical symptoms are not always clear cut. Other potential diseases that can explain the clinical picture include pneumonia, pharyngitis, acute cardiovascular disease and isolated pharyngeal abscess.
After stabilization, patients need to be transferred as soon as possible from the emergency department for surgical operation. The goal of surgery is the removal of all necrotic tissue, as well as the examination of the structures and organs within the mediastinum. Surgery is performed with a cervical approach and consists of a thoracotomy [10]. Pus and necrotic substance should be drained and any esophageal rupture needs to be closed.
Prognosis
Mediastinitis has elevated mortality, with figures ranging from 11.1% up to 50% in some case series, and reaching 67% in patients with comorbidities. Descending necrotizing mediastinitis tends to be more severe with mortality levels between 11.1% and 34.9%.
Prognosis can be improved if the disease is caught early and treated immediately and aggressively. Preventive measures can also help in avoiding the development of the condition, particularly following surgeries in the thorax area [1].
Etiology
Mediastinitis has a wide range of causes. These include esophageal rupture, ingestion of a foreign body such as a fish or a chicken bone, infection subsequent to surgery in the thorax as well as medical errors during procedures involving the esophagus or the trachea such as upper endoscopy, surgery in the esophagus, dilatation of the esophagus, transesophageal biopsy, dilatation of the trachea, bronchoscopy and transbronchial biopsy. Infections of the head and neck that can also cause mediastinitis usually affect the pharynx, the sinuses, the teeth or the tonsils [2] [3]. The disease may also very rarely be seen as a complication of laparoscopic cholecystectomy.
It can sometimes result when performing an intubation procedure and the esophagus or the hypopharynx is perforated. In these cases, symptoms appear directly after intubation or, in rare instances, they may manifest much later. The condition should be suspected if the state of the patient worsens significantly with circulatory collapse and evidence of sepsis.
Although the most commonly involved organisms are bacteria, mediastinitis can also be caused by infections with fungi, particularly candida species. Infection with candida occurs in 0.3% of all cases of cardiothoracic surgery.
Mediastinitis caused by tuberculosis should be suspected in patients with a history of the disease. It usually takes place when a lymph node ruptures within the mediastinum. Diagnosis is challenging since patients are commonly asymptomatic initially or may present with very few signs and symptoms. It is usually established with imaging modalities such as MRI.
Fibrosing mediastinitis is a very rare disease, caused by an exaggerated fibrotic reaction. It follows granulomatous disease or histoplasmosis. Typical symptoms result from pressure over structures and organs present within the mediastinum and include shortness of breath, cough, obstruction of the superior vena cava, pain in the chest and hemoptysis.
Epidemiology
Mediastinitis has become a rare disease in the developed world after the introduction of antibiotics and appears almost exclusively in patients who have undergone cardiothoracic surgery, particularly heart transplants. Nonetheless, the condition can still be commonly encountered in developing nations among patients who suffer from infections in the head and neck area.
One study suggests that in a sample of 10,000 subjects with a history of cardiothoracic surgery, the incidence of the condition was reported to be 1% [4]. Other studies report that it is six times more common among males than females, and tends to affect patients in their third and fifth decades, although cases involving patients who are as young as 2 months and older than 80 years have been also described.
Pathophysiology
Infections in the mediastinum can only take place if there is a breach to the normal structures and organs contained in it. This commonly occurs after injury to the trachea, the sternum, the bronchi and the esophagus. It can also take place when infections from the cervical and pharyngeal regions spread in a downward direction.
Descending necrotizing mediastinitis refers to an extension of the infection from the cervical and head area into the mediastinum and is usually the most common cause in the developing world. Some common descending infections involved in mediastinitis are sinusitis, pharyngeal abscess, odontogenic infections and various other ear, nose and throat infections.
The infectious spread is the most devastating form of mediastinitis. The infection has a tendency to spread in the downward direction because of the effects of gravity, negative intrathoracic pressure, and normal breathing. The condition is very prevalent in the developing world because of poor access to medical care, resulting in ineffective treatment of the infection [5] [6].
Causes of direct injury are diverse and include ingestion of foreign bodies such as chicken or fish bones, a motor vehicle accident, malignancy, surgery in the thorax, Boerhaave syndrome, dilatation of the trachea or the esophagus, bronchoscopy, endoscopy and endotracheal intubation.
The infection associated with mediastinitis is polymicrobial in nature, with the involvement of both aerobic and anaerobic organisms. However, obligates anaerobes are 10 times more common than aerobes. Bacteroides species is the most frequently involved anaerobe and streptococcus is the most common one. A range of other species has been implicated such as fusobacterium, staphylococcus, escherichia coli, haemophilus influenzae, enterobacter cloacae, peptostreptococcus, pseudomonas aeruginosa, and histoplasmosis. Mediastinitis with methicillin-resistant staphylococcus aureus has been recently identified, raising great concern [7].
Prevention
It is important to follow medical advice after surgery. In case a wound opens or there is associated swelling and fluctuance, the patient needs to be in immediate contact with his surgeon. The patient should also measure regularly his temperature and report any abnormalities to the medical team.
Individuals with diabetes should have their blood sugar levels very well controlled. Even patients normally on oral medication may need insulin injections to decrease the risk of infections.
Patients who receive radiation therapy after surgery are also at increased risk. They require continuous monitoring and follow-up to detect any infection or a breakdown in the wound. This is essential in the prevention of severe complications.
Other preventive measures include wearing a supporting bra, especially for obese patients or female patients with large breasts. Increased weight can lead to elevated stress over the wound, increasing the risk of poor wound healing.
Patients should also not use any creams, ointments or lotions before receiving appropriate medical advice. Antibacterial products are not recommended and may actually worsen the healing process. In addition, patients are generally advised to restrict movement and the lifting of heavy weights.
Summary
Mediastinitis is an infection of the mediastinum that can result from either a damage to the structures within it or from a spread of the infection from the head and neck region. In the developing world, the most common cause is an uncontrolled infection, most frequently involving the teeth and oral cavity, and spreading in a downward fashion to the mediastinum [1]. In contrast, most cases in the developed countries occur after an injury; for example, a surgery in the thorax or a motor vehicle accident. Patients develop symptoms gradually before presenting to the emergency department. History taking is the most critical step in establishing the diagnosis, in addition to the overall clinical picture. Nonetheless, magnetic resonance imaging (MRI) can be used to confirm the diagnosis. Mediastinitis requires urgent treatment with fluid resuscitation and antibiotic administration, after securing the airway. Patients are eventually referred for surgical management, which consists of debridement and exploration of the mediastinal area. Mediastinitis has a high mortality rate, especially when comorbidities are also present.
Patient Information
Mediastinitis is a severe infection of the mediastinum that can occur after injury or after the spread of infection from the head and neck area into the mediastinum. In the developing world, the condition most commonly occurs in conjunction with an infection in the hand and neck, most frequently in the teeth and the oral cavity. In contrast, an injury is the most common cause of mediastinitis in the developed world especially following surgery in the thorax. Patients generally develop gradual symptoms such as shortness of breath, confusion, fever and chills, swelling in the neck, pain in the chest and upon swallowing. They frequently have a history of infection, surgery in the thorax, a motor vehicle accident or an interventional procedure such as an endoscopy (a procedure used to visualized the digestive tract), bronchoscopy (procedure employed to look into the respiratory airways) or malignancy. Treatment of the condition is emergent and the doctors pay particular attention to securing the respiratory airway, sometimes with intubation. Fluid resuscitation is also very important since many patients may show signs of collapse due to the severity of the infection (sepsis). Patients should also be referred for surgery, in which necrotic tissue is removed and the thorax is explored to ensure the status of critical organs and structures in the area. The development of mediastinitis can be prevented if patients follow medical advice and recommendation after surgery and if they closely monitor incision wounds. Prevention of risk factors of infections such as diabetes and cardiovascular disease can also greatly help. Mediastinitis has a poor prognosis, but can be treated if diagnosis and management are prompt and aggressive.
References
- Papalia E, Rena O, Oliaro A, et al. Descending necrotizing mediastinitis: surgical management. Eur J Cardiothorac Surg. 2001 Oct; 20(4):739-42.
- Sichel JY, Attal P, Hocwald E, et al. Redefining parapharyngeal space infections. Ann Otol Rhinol Laryngol. 2006 Feb; 115(2):117-23.
- Collin J, Beasley N. Tonsillitis to mediastinitis. J Laryngol Otol. 2006 Nov; 120(11):963-6. Epub 2006 Jul 6.
- Eklund AM, Lyytikainen O, Klemets P, et al. Mediastinitis after more than 10,000 cardiac surgical procedures. Ann Thorac Surg. 2006 Nov; 82(5):1784-9.
- Scaglione M, Pezzullo MG, Pinto A, et al. Usefulness of multidetector row computed tomography in the assessment of the pathways of spreading of neck infections to the mediastinum. Semin Ultrasound CT MR. 2009 Jun; 30(3):221-30.
- Cirino LM, Elias FM, Almeida JL. Descending mediastinitis: a review. Sao Paulo Med J. 2006 Sep 7; 124(5):285-90.
- Simsek Yavuz S, Sensoy A, et al. Methicillin-Resistant Staphylococcus aureus Infection: An Independent Risk Factor for Mortality in Patients with Poststernotomy Mediastinitis. Med Princ Pract. 2014 Aug 12.
- Rehman SM, Elzain O, Mitchell J, et al. Risk factors for mediastinitis following cardiac surgery: the importance of managing obesity. J Hosp Infect. 2014 Jul 21.
- Scaglione M, Pinto A, Giovine S, et al. CT features of descending necrotizing mediastinitis--a pictorial essay. Emerg Radiol. 2007 Jun; 14(2):77-81.
- Chen KC, Chen JS, Kuo SW, et al. Descending necrotizing mediastinitis: a 10-year surgical experience in a single institution. J Thorac Cardiovasc Surg. 2008 Jul; 136(1):191-8.