For example, foreign body aspiration, in which someone inhales an object, can cause pneumomediastinum (and lead to subcutaneous emphysema) by puncturing the airways or by increasing the pressure in the affected lung(s) enough to cause them to burst.Subcutaneous emphysema of the chest wall is commonly among the first indications that barotrauma, damage caused by excessive pressure, has occurred; it suggests that the lung was subjected to significant barotrauma. Thus the phenomenon may occur in diving injuries.Trauma to parts of the respiratory system other than the lungs, such as rupture of a bronchial tube, may also cause subcutaneous emphysema. Air may travel upward to the neck from a pneumomediastinum that results from a bronchial rupture, or downward from a torn trachea or larynx into the soft tissues of the chest. It may also occur with fractures of the facial bones, neoplasms, during asthma attacks, when the Heimlich maneuver is used, and during  childbirth.Injury with pneumatic tools, those that are driven by air, is also known to cause subcutaneous emphysema, even in extremities (the arms and legs). It can also occur as a result of rupture of the esophagus; when it does, it is usually as a late sign. Medical treatment
Subcutaneous emphysema is a common result of certain types of surgery; for example it is not unusual in chest surgery. It may also occur from surgery around the esophagus, and is particularly likely in prolonged surgery. Other potential causes are positive pressure ventilation for any reason and by any technique, in which its occurrence is frequently unexpected.
If identified early, before presumed intestinal wall ischemia has resulted in tissue breakdown and necrosis, the cecal volvulus can be detorsed laparoscopically. It has been associated to several diseases, including Huntingtons disease. Other
Laparotomy for other forms of volvulus, especially anal volvulus. References
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CT of an abdomen with sigmoid volvulus