Blunt or penetrating chest trauma to the intrathoracic airways, foreign body in the intrathoracic airways, procedures like bronchoscopy, bronchial brushing, transbronchial biopsy, needle aspiration and neoplasms of the intrathoracic airways can cause pneumomediastinum. Dolutegravir chemical structure Pneumomediastinum can also be caused by direct disruption

of alveoli (penetrating trauma, surgery) or spontaneous alveolar rupture (between alveolus and adjacent bronchovascular sheath). Esophageal perforation, pneumoperitoneum or pneumoretroperitoneum (gastric or intestinal perforation, diverticulitis, pneumatosiscystoidesintestinalis, endoscopy, biopsy, and infection) may also give rise to pneumomediastinum.

Penetrating trauma to neck or chest like surgical procedures (tracheotomy, mediastinoscopy), chest tube insertion, acute bacterial mediastinitis and head ATM/ATR phosphorylation and neck infections with gas producing organisms may also cause pneumomediastinum.1 When pressure gradient becomes sufficient to rupture alveolar walls, air may enter the pulmonary interstitium and bronchovascular sheath. This air may pass through the fascial planes which connect cervical soft tissues with the mediastinum and retroperitoneum, permitting aberrant air arising in any Cell press one of these areas to spread elsewhere.2, 3 and 4 Subcutaneous emphysema may be observed in association with pneumothorax or pneumomediastinum as a result of pathological changes in the respiratory

tract. Spontaneous pneumomediastinum has been reported in several forms of pulmonary tuberculosis like miliary, silico tuberculosis and cavitary tuberculosis.5 and 6 Spontaneous subcutaneous emphysema from caverno–pleuro–subcutaneous fistula is rare.7 and 8 In our case the CT scan revealed a communication of pulmonary cavity to the subcutaneous tissue (caverno–pleuro–soft tissue fistula). The cavity was probably under tension that allowed passage of bronchial air through a tear to create subcutaneous emphysema. Subcutaneous emphysema may result in cosmetic deformity and can rarely be associated with airway compromise, respiratory failure and death. Treatment involves treating the underlying condition. Sometimes decompression may be done by making bilateral 3-cm infraclavicular incisions down to the pectoralis fascia.9 Fenestrated catheters have been used in the treatment of subcutaneous emphysema.10 The author had no conflict of interest to disclose. “
“In recent years, increased attention has received obstructive sleep apnea/hypopnea syndrome (OSA/HS).