Pneumomediastinum can occur in healthy adults in the absence of trauma if a triggering event occurs.
Patient selection: healthy adult without trauma
Mechanism: increased intra-alveolar pressure
Pneumomediastinum can be clinically overlooked if:
(1) it is mild
(2) soft tissue and subcutaneous emphysema are absent
(3) imaging studies (CT or MRI scan) are not performed
Risk factors:
(1) Valsalva maneuver
(2) asthma
(3) cough
(4) emesis (postoperative, pregnancy, other)
(5) barotrauma
Differential diagnosis:
(1) pneumomediastinum following penetrating trauma
(2) soft tissue emphysema and pneumomediastinum following dental surgery
