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.
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 .
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.
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 .
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.
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.
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 . Pus and necrotic substance should be drained and any esophageal rupture needs to be closed.
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 .
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  . 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.
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% . 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.
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  .
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 .
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.
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.
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 . 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.
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.