Subcutaneous emphysema can be spontaneous or traumatic, but is associated with avoidable causes such as inadequate chest tube drainage, particularly due to poor tube placement, anchorage and blockage, and also with side-port migration into the subcutaneous tissue. It is associated with an increased morbidity and mortality, and may indicate the need for urgent chest tube replacement.

These results fail to demonstrate a benefit of intramuscular atropine as premedication for fibreoptic bronchoscopy.