Post-surgical hydropneumopericardium: a case report of dramatic increase in the apparent size of pericardial effusion with positional changes

BACKGROUND: Pneumopericardium is an uncommon clinical finding. It most commonly occurs after chest trauma but can also emerge as a complication following interventional or surgical procedures and can result in life-threatening complications. A high index of clinical suspicion should be present and once the condition is recognized, it should be managed promptly. Paucity of literature on pneumopericardium makes outlining any new case of paramount importance to emphasize the aspects of diagnosis and management of this rare condition. CASE SUMMARY: A 59-year-old woman with severe mitral valve and moderate tricuspid valve regurgitation underwent mitral and tricuspid valve repair with uneventful post-operative in-hospital stay. She presented 10 days after discharge with progressive shortness of breath. Chest X-ray revealed right hydropneumothorax. Transthoracic echocardiography (TTE) performed in the emergency department showed an apparently small pericardial effusion with patient in supine position; the effusion size increased substantially when imaging in left lateral decubitus, with presence of intrapericardial air bubbles. Computed tomography scan of the chest confirmed the presence of right hydropneumothorax and hydropneumopericardium, with a communicating pleuro-pericardial tract. The patient underwent chest tube placement which successfully decompressed both pleural and pericardial space. DISCUSSION: Hydropneumopericardium is a rare post-operative complication. Comprehensive TTE with imaging from multiple acoustic windows is mandatory when evaluating the extent of pericardial effusion. Presence of cardiac tamponade is crucial in determining the management plan.