Pneumomediastinum in Children
Belching-Related Pneumomediastinum
JOHN BISHARA, DO, THOMAS O’DONNELL, MD, CATHERINE CARONIA, MD, and RAJESH SAVARGAONKAR, MD
Good Samaritan Hospital Medical Center, West Islip, New York
A 16-year-old boy presented to the pediatric emergency department with a 1-day history of progressively worsening neck and chest pain. He described his neck pain as a squeezing tightness near the sternal notch that intensified with swallowing and coughing. He denied hoarseness, vocal change, shortness of breath, or dyspnea. Interestingly, the patient volunteered that he had participated in a “belching competition” 36 hours before presentation.
Figure 1 – A lateral chest radiograph showed the presence of air in the retrosternal and prevertebral spaces of a 16-year-old boy, indicating pneumomediastinum.
On physical examination, the boy’s vital signs were normal and stable. He was in no acute distress and spoke in full sentences. No crepitus or subcutaneous emphysema was appreciated, and the lungs were clear to auscultation, with good air entry bilaterally.
Radiographs (Figures 1 and 2) and computed tomography (CT) scans of the chest and neck were ordered (Figures 3 and 4) and confirmed pneumomediastinum but failed to identify an etiology. Because spontaneous pneumomediastinum is uncommon, the patient was admitted to the pediatric floor for further workup and evaluation. Otolaryngology was consulted.
Figure 2 – A cervical radiograph showed the presence of air in the retropharyngeal space.
The otolaryngologist performed flexible fiberoptic nasopharyngolaryngoscopy and discovered a ruptured laryngeal vestibule, which likely had resulted from the excessive belching and likely had caused the pneumomediastinum. The patient’s respiratory status remained stable, and he was discharged home with instructions to avoid forceful belching. He was advised that the pneumomediastinum would resolve spontaneously in a few days.
DISCUSSION
Pneumomediastinum is uncommon in pediatric patients, and its etiology is multifactorial. Spontaneous pneumomediastinum is not associated with chest trauma, lung disease, mechanical ventilation, or other invasive procedures. It is, however, associated with activities that lead to an elevation in alveolar pressure, such as forceful coughing, vomiting, Valsalva maneuvers, playing musical wind instruments, and using inhaled illicit drugs.1 The unique cause of our patient’s pneumomediastinum was a vestibular rupture secondary to belching.
Figure 3 – A chest CT scan revealed the presence of air in the paratracheal region.
The typical development of pneumomediastinum is described in a sequence of events known as the Macklin effect: alveolar rupture, air dissection along the bronchovascular sheath, and free air reaching the mediastinum.2 The dissection of free air may not be confined to the mediastinum. Because the mediastinum communicates with the spaces of the neck, air that once had been within the mediastinum may dissect through tissue planes, causing pneumopericardium and pneumothorax.3 With a vestibular rupture, air tracks along the retropharyngeal space where it may communicate with the mediastinum.
Our patient likely had a congenital defect in the laryngeal ventricle, which predisposed him to a dehiscence with the increased pressure of belching. The amount of air tracking along the retropharyngeal space was not large enough to produce subcutaneous emphysema.
Figure 4 – A sagittal CT scan of the neck showed the presence of air in the paratracheal space.
Chest radiography can reveal air within the mediastinal space and usually is the first step in identification of pneumomediastinum. The typical features of pneumomediastinum on chest radiography are a result of air outlining the anatomic structures in the mediastinum (ie, margins of the heart, retrosternal space, trachea).3 Chest CT can provide additional diagnostic information about the presence of coexisting illness or major injury to the pulmonary and digestive tracts.4 Nevertheless, the etiology of the pneumomediastinum may not be revealed on radiographs or CT scans, and further workup may be needed.
Medical therapy depends on the patient’s clinical status. Management is conservative and typically consists of treating the underlying cause (if identified), rest, analgesics, clinical monitoring, and follow-up. Maneuvers that increase pulmonary pressure should be avoided. Obtaining a thorough history may help identify the cause or contributory factors. Predisposing factors should be identified and controlled to prevent recurrence. Most children with pneumomediastinum are asymptomatic, and the natural course of the condition is spontaneous resolution.5
REFERENCES:
1. Chalumeau M, Le Clainche L, Sayeg N, et al. Spontaneous pneumomediastinum in children. Pediatr Pulmonol. 2001;31(1):67-75.
2. Macklin CC. Pneumothorax with massive collapse from experimental local over-inflation of the lung substance. Can Med Assoc J. 1937;36(4):414-420.
3. Zylak CM, Standen JR, Barnes GR, Zylak CJ. Pneumomediastinum revisited. Radiographics. 2000;20(4):1043-1057.
4. Dissanaike S, Shalhub S, Jurkovich GJ. The evaluation of pneumomediastinum in blunt trauma patients. J Trauma. 2008;65(6):1340-1345.
5. Macia I, Moya J, Ramos R, et al. Spontaneous pneumomediastinum: 41 cases. Eur J Cardiothorac Surg. 2007;31(6):1110-1114.
Asthma-Related Pneumomediastinum
SHAHNAWAZ AMDANI, MD, ADITYA BADHEKA, MD, THAIS QUELIZ, MD, and MAGDA MENDEZ, MD
Lincoln Medical and Mental Health Center, Bronx, New York
A 12-year-old boy with a history of early-onset, moderate, persistent asthma came to the emergency department with complaints of chest tightness and difficulty breathing. On arrival, he was tachycardic (heart rate, 124 beats per minute) and tachypneic (respiratory rate, 28 breaths per minute) with normal oxygen saturation (96% on room air). On examination, the patient had decreased air entry bilaterally with intercostal and subcostal retractions.
A complete blood count (CBC), a basic metabolic panel, and chest radiography were done. The CBC showed leukocytosis with neutrophilia, the metabolic panel was normal, and chest radiographs showed retrocardiac consolidation (Figure 5).
Figure 5 – Initial chest radiograph showed the presence of pneumomediastinum and subcutaneous emphysema in a 12-year-old boy with a history of asthma.
The patient was given nebulized albuterol and ipratropium bromide and intravenous methylprednisolone and magnesium sulfate. He had one episode of nonbilious, nonbloody vomiting. He was admitted to the pediatric intensive care unit (PICU) for further management.
On arrival to the PICU, he was tachypneic (respiration rate, 40 breaths per minute) and hypoxic (90% oxygen saturation on room air). He was started on continuous albuterol (20 mg/hour for 4 hours) and bilevel positive airway pressure (BPAP) respiratory ventilation. The patient gradually required more oxygen, with markedly decreased air entry bilaterally. Repeat chest radiography showed pneumomediastinum and subcutaneous emphysema of the chest wall and soft tissue of the left neck (Figure 6). BPAP was discontinued immediately. Subsequent radiographs showed worsening pneumomediastinum and subcutaneous emphysema along the left chest wall and bilateral neck.
Figure 6 – Chest radiograph showed worsening of pneumomediastinum and subcutaneous emphysema with BPAP ventilation.
The patient had no signs of hemodynamic compromise. He was managed with nebulized albuterol, corticosteroids, antibiotics, and high-flow oxygen. The child responded well to treatment during the 3-day stay in the PICU. Serial chest radiographs showed resolution of pneumomediastinum before discharge (Figure 7).
DISCUSSION
Pneumomediastinum is rare in children, but when it does occur, asthma exacerbations and infections are among the most common medical causes.1 Patients with asthma are at higher risk for pneumomediastinum because of mucous plugging, which can be compounded by ventilatory efforts (eg, Valsalva maneuver, BPAP).
Figure 7 – Chest radiograph before discharge showed resolving pneumomediastinum and subcutaneous emphysema.
Patients with pneumomediastinum may be asymptomatic, or, like our patient, they may have chest pain or dyspnea.2 The most common signs and symptoms are subcutaneous emphysema, sore throat or neck pain, and the Hamman sign (precordial crunching on auscultation, synchronous with each heartbeat).1 These signs, along with diminished oxygen saturation, should heighten suspicion of pneumomediastinum.
Chest radiography confirms the diagnosis; treating the underlying cause, rest, analgesics, and clinical monitoring comprise management.3,4
Among the possible sequelae of pneumomediastinum are pneumothorax, pneumoperitoneum, pneumoretroperitoneum, and pneumopericardium, the latter of which can impede venous return, leading to cardiac arrest. Nevertheless, complications of pneumomediastinum are exceedingly rare. That nearly all patients recover uneventfully suggests that early recognition and treatment may be sufficient in most instances of pneumomediastinum.
REFERENCES:
1. Damore DT, Dayan PS. Medical causes of pneumomediastinum in children. Clin Pediatr (Phila). 2001;40(2):87-91.
2. Bejvan SM, Godwin JD. Pneumomediastinum: old signs and new signs. AJR Am J Roentgenol. 1996;166(5):1041-1048.
3. Scichilone N, Buttacavoli M, Camarda G, Marchese M, Bellia M, Spatafora M. A 15-year-old boy with anterior chest pain, progressive dyspnea, and subcutaneous emphysema of the neck. J Allergy (Cairo). 2009;2009:496890.
4. Chalumeau M, Le Clainche L, Sayeg N, et al. Spontaneous pneumomediastinum in children. Pediatr Pulmonol. 2001;31(1):67-75.