Pneumopericardium represents gas (usually air) within the pericardium, thus surrounding the heart.
Underlying causes include:
- positive pressure ventilation
- thoracic surgery/pericardial fluid drainage
- penetrating trauma
- blunt trauma (rare)
- infectious pericarditis with gas-producing organisms
- between the pericardium and an adjacent air-containing organ (i.e. stomach or esophagus)
Plain radiograph and CT
On both chest radiographs and CT, appearances are characteristic, the heart being partially or completely surrounded by gas, with the pericardium sharply outlined by gas density on either side. Continuous diaphragm sign may be present.
Treatment and prognosis
A pneumopericardium can usually be distinguished from pneumomediastinum, since gas in the pericardial sac should not rise above the anatomic limits of the pericardial reflection on the proximal great vascular pedicle. Also on radiographs obtained with the patient in the decubitus position, gas in the pericardial sac will shift immediately, while gas in the mediastinum will not shift in a short interval between films.
Occasionally, it may not be possible to distinguish pneumopericardium from pneumomediastinum on plain film.
- 1. Mirvis SE, Indeck M, Schorr RM et-al. Posttraumatic tension pneumopericardium: the "small heart" sign. Radiology. 1986;158 (3): 663-9. Radiology (abstract) - Pubmed citation
- 2. Karoui M, Bucur PO. Images in clinical medicine. Pneumopericardium. N. Engl. J. Med. 2008;359 (14): e16. doi:10.1056/NEJMicm074422 - Pubmed citation
- 3. Capizzi PJ, Martin M, Bannon MP. Tension pneumopericardium following blunt injury. J Trauma. 1995;39 (4): 775-80. J Trauma (link) - Pubmed citation