A 70 y.o. woman comes in with COPD has acute SOB
Her xray is shown
what do you notice on the xray?
This was not a pneumothorax although it can sometimes be difficult to tell. What looks like the edge of the lung is actually white where in a pneumothorax it would be dark. There are several conditions seen recently in the ED causing “pneumothorax mimics”. A chest tube is not indicated in these situations.
1.SKIN FOLD MIMICKING A PNEUMOTHORAX
2.PNEUMOTHORAX EX VACUO
This is a patient with an endobronchial valve causing pneumothorax ex vacuo; seen best on the lateral. No chest tube is indicated but rather relief of the obstruction.
Pneumothorax ex-vacuo was first described as the result of gas being drawn into the pleural space due to an actual endobronchial obstruction with lobar collapse. The treatment is NOT a chest tube but rather to relieve the obstruction.
Currently, endobronchial valves are sometimes placed to collapse a part of the lung which is emphysematous and there by shunting air to less diseased parts of the lung. They cause a functional collapse of the lobe distal to the valve . There is a marked increase in negative intrapleural pressure around the collapsed lobe and nitrogen gas diffuses into the pleural space mimicking a pneumothorax.
This phenomenon can occur after thoracentesis if the underlying lung fails to expand. Acute bronchial obstruction from mucous plugs, aspirated foreign bodies or a malpositioned endotracheal tube have all been shown to cause this phenomenon.
3. PREVIOUS SURGERY MIMICKING A PNEUMOTHORAX
The Clagett procedure can be confusing on CXR
A clagett is much easier to see on exam or CT.. Fortunately in humans the pleural spaces do not connect. However, the pleural spaces do connect in buffalo making them easy to kill with an arrow to one chest cavity.
Our patient had LLL collapse and was bronched showing no endobrochial lesion but thick mucous obstructing the LLL and present in the LUL and lingula. Lavage studies grew E coli. She was discharged on a 7 day couse of levofloxacin.
Our patient had LLL pneumonia and collapse explaining the marked volume loss on the L.
Kim Y, Susanto I, Lazar C, et al. BMC Pulmonary Medicine. Pneumothorax Ex-vacuo or “trapped lung” in the setting of hepatic hydrothorax. 2012 ,78: https://doi.org/10.1186/1471-2466-12-78. Dec 17 2012be dark.
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Bayes A, Wilson J, Chiu R, et al. Clagett open-window thoracostomy in patients with empyema who had and had not undergone neumonectomy. 1987 Can J Surg. Sep;30(5):329-31.
Klooster K, Slebos D. Endobroncial valves for the treatment of advanced emphysema. Chest 2021 May;1599(5):1833-1842.