Swollen neck and crepitus after bouts of cough

Case History

A 68-year-old Malay man, a chronic smoker with underlying chronic obstructive airway disease (COAD), hypertension, diabetes mellitus and history of pulmonary tuberculosis (more than 30 years ago), complained of sudden onset of neck swelling after he had bouts of cough in the morning. It was associated with difficulty in breathing and a change in voice. The swelling was increasing in size with each successive coughing episode. He admitted having a mild non-productive cough 1 week prior to presentation. On examination, the neck swelling extended superiorly to the cheek and inferiorly to the upper chest wall. Palpation at the swollen area revealed the presence of crepitus. A chest radiograph was performed (Figure 1).

Figure 1.

Questions

1. Describe the abnormalities in the chest radiograph.

2. What is the diagnosis?

3. Explain the pathophysiological changes of this patient clinical manifestation.

4. State the important points in the history to suggest the diagnosis.

5. What is the next step of management?

Answers

1. Extensive subcutaneous emphysema involving the neck region and extended to right anterior soft tissue of the chest. The right paratracheal outline becomes more conspicuous suggestive of pneumomediastinum. Diffuse lung fibrotic changes are seen predominantly at biapical regions with multiple small subpleural bullae. Subsegmental collapse of the right lower lobe with elevated right hemidiaphragm was noted. The elevated right hemidiaphragm and deviated trachea (to the right) could be due to right upper lobe fibrosis. There is airspace between the right hemidiaphragm and the inferior border of the heart. Compensatory hyperinflation of the left lung was evident.

2. The diagnosis is spontaneous pneumomediastinum with extension to the subcutaneous spaces in the neck, cheek and chest (Macklin effect). Compared to the subcutaneous emphysema, spontaneous pneumomediastinum is rare. The free air that originates from the rupture of alveoli tracks along peribronchial vascular sheaths towards the hilum of the lung before it extends proximally within the mediastinum.1 In a series of 62 consecutive adults patients diagnosed to have spontaneous pneumomediastinum in Mayo Clinic, 44% had one or more pre-existing lung disorders such as interstitial lung disease, asthma, bronchiolitis obliterans syndrome, bronchiectasis, COAD, bronchogenic or metastatic cancer and cystic lung lesions.2

3. Pathophysiological changes:

   • Bouts of cough could have caused alveoli rupture

   • This results in air leaks

   • Air escaped into the mediastinum through the bronchovascular sheaths

   • From there, air dissects through the planes of perivascular fascia into the subcutaneous spaces in the neck and the chest

4. Important points in the history:

   • History of bouts of cough

   • Dyspnoea and change in voice

   • Presence of risk factor such as COAD

   • Subcutaneous emphysema

   • Chest radiograph changes

   Besides cough and dyspnoea, common presenting complaints also include chest pain (63% of patients), light-headedness, dysphagia and dysphonia.2

5. The patient should be referred urgently to monitor the symptoms and signs of impending upper airway compromise. Besides breathing pattern and oxygen saturation, measurement of neck circumference is one of the reliable methods of monitoring. However, most of the cases will resolve spontaneously by conservative treatment in 1 to 2 weeks.3,4 Treatment of chest infection should be started and reactivation of old pulmonary tuberculosis should be screened. Continuous monitoring of oxygen saturation, respiratory rate, blood pressure and pulse rate may also be useful to detect complications such as reduced venous return and pneumopericardium.