I want to talk about one interesting finding on CXR that I came across while rounding in ICU. How often do we see a spontaneous pneumomediastinum (SPM) with SQ emphysema? The patient was a young female admitted earlier with asthma exacerbation. The patient reported coughing and shortness of breath on admission. No significant chest pain was reported. On hospital day 2 she developed some chest discomfort. Portable CXR revealed evidence of the spontaneous pneumomediastinum and SQ emphysema (see image above with arrows pointing to subcutaneous air). Literature search came up with a review paper from CHEST. The mechanism of SPM is terminal alveolar rupture with dissection of air into hilum, then mediastinum and later into the tissues of the neck along the fascial planes. Very interesting! It could even happen while straining, sneezing or inflating party balloons. Many of those patients do, though, have some precipitating conditions like Asthma. Illicit drug users (specifically inhalational drugs) are at higher risk as well. The most common presentation is chest pain and shortness of breath.
The patient in ICU did fine and went home several days later.