MANAGEMENT
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합병증 발생 여부에 따라 치료 달라짐
Uncomplicated
Uncomplicated SPM is managed conservatively in the outpatient setting with analgesia, rest, and avoidance of maneuvers that increase pulmonary pressure (Valsalva or forced expiration, including spirometry) [61,62]. Asthma or other underlying lung disease is treated as indicated.
●Disposition – For patients with mild and stable symptoms and no respiratory distress and normal oxygenation, it is reasonable to discharge after several hours of observation in the emergency department, provided that any underlying triggers (asthma, vomiting) are well controlled. This approach is supported by several large case series, which document the benign clinical course for such patients [3,13,62]. As an example, in a series of 183 patients with SPM (both primary and secondary), only six returned within 96 hours of discharge and none of these had a complication requiring intervention [3].
Patients with moderate to severe symptoms or progression should be admitted to the hospital for further monitoring. For this group, therapy with high-concentration oxygen has been used in an effort to enhance nitrogen washout [63,64]. However, if such patients have underlying chronic lung or airway disease that predisposes to atelectasis, 100% oxygen therapy should be administered with caution because it may lead to absorptive atelectasis [65].
●Follow up – Patients who are discharged from the emergency department should generally be reevaluated as an outpatient within 24 to 48 hours. Repeat imaging is generally not needed for patients with uncomplicated SPM unless new or worsening symptoms develop.
●Air travel – There are little data to support specific recommendations regarding air travel in an infant or child who has experienced a recent SPM. The interval after SPM when a child is at risk for recurrence during air travel has not been established, especially for children of different ages or for different underlying clinical conditions. The risk is uncertain but is probably low once the air leak has resolved. Some clinicians permit air travel approximately two weeks after radiographic resolution of SPM, provided that any underlying disease, such as asthma, is well controlled. This advice is based upon guidelines for patients with pneumothorax, about which the evidence is also quite limited [66]. (See "Pneumothorax and air travel".)
●Diving – SCUBA diving is generally contraindicated in patients with a history of SPM, with or without pneumothorax. These patients are at risk for recurrence while SCUBA diving, with potentially devastating consequences. However, there is substantial uncertainty about several aspects of this risk, including whether the risk of recurrence decreases years or decades after a first episode of SPM [67]. For patients with recurrent SPM, SCUBA diving is absolutely contraindicated. (See "Complications of SCUBA diving".)
Complicated
●Pneumothorax with pneumomediastinum is managed similarly to isolated pneumothorax (see "Spontaneous pneumothorax in children")
●Esophageal perforation (Boerhaave syndrome) with secondary pneumomediastinum requires intensive medical or surgical management (see "Boerhaave syndrome: Effort rupture of the esophagus")
●For tension pneumomediastinum, limited mediastinotomy may be performed to drain the pneumomediastinum [33] (see "Thoracic trauma in children: Initial stabilization and evaluation")
●Pneumopericardium occasionally occurs with SPM [30,31]; management requires vigilance for the possibility of cardiac tamponade (see "Diagnosis, management, and prevention of pulmonary barotrauma during invasive mechanical ventilation in adults", section on 'Others')
OUTCOME
The prognosis of pneumomediastinum is much worse when it occurs in association with pneumothorax, measles, or an underlying lung disease other than asthma [23,44]. With respect to measles, SPM might be considered a marker for more severe underlying disease, rather than a direct contributor to mortality.
SUMMARY AND RECOMMENDATIONS
●Definition – Spontaneous pneumomediastinum (SPM) is the presence of gas in the mediastinum in the absence of trauma and is generally benign and self-limited. (See 'Definition' above.)
●Triggers – SPM mainly affects children and young adults. Triggers for SPM include respiratory conditions (such as asthma, respiratory tract infections, Valsalva maneuver, inhalation of illicit drugs, etc), gastrointestinal disorders (such as vigorous vomiting or perforation of the esophagus, stomach, colon, etc) or other etiologies (intense physical effort, seizure, etc) (table 1). (See 'Predisposing conditions or triggers' above.)
●Clinical presentation and diagnosis – SPM typically presents with the sudden onset of retrosternal chest pain, subcutaneous emphysema, and, sometimes, dyspnea. Physical examination can show a subcutaneous crepitus of the neck and upper chest. The heart examination may reveal a characteristic crunching sound that is synchronous with systole (Hamman sign) (movie 1). The diagnosis is confirmed by plain films of the chest (image 4). (See 'Evaluation' above and 'Diagnosis' above.)
●Further evaluation – In addition to establishing the diagnosis of SPM, the goals of the evaluation are to assess potential triggers (eg, asthma or vomiting), exclude other causes of the presenting symptoms (pneumothorax, esophageal perforation), and evaluate for complications (tension pneumomediastinum). Complicated SPM is rare in the absence of trauma. (See 'Differential diagnosis' above and 'Physical examination' above.)
●Management – Treatment for uncomplicated SPM is supportive, consisting of analgesia, rest, and avoidance of maneuvers that increase pulmonary pressure (Valsalva or forced expiration, including spirometry). Asthma or other underlying lung disease is treated as indicated. Most patients recover without sequelae within a few days, and recurrence is rare. (See 'Management' above and 'Outcome' above.)
