A case of cardiac tamponade with a "small" pericardial effusion and superior vena cava syndrome.

In this article, we report a case of a previously healthy 11-year-old male who presented to our university hospital with a mediastinal mass, a left and right pleural effusion, and a small pericardial effusion of 5 mm, detected on computed tomography scan and echocardiography. On assessment, he had all the clinical features of superior vena cava syndrome and tamponade, including muffled heart sounds, tachycardia, and pulsus paradoxus. The patient developed increasing respiratory distress requiring tracheal intubation and mechanical ventilation, and despite drainage of his larger pleural effusion, continued to experience symptoms of respiratory distress. Finally, the small pericardial effusion was confirmed on echocardiography and drained after a clinical diagnosis of cardiac tamponade, leading to dramatic improvement in the patient's cardiovascular status. Curiously, on pericardiocentesis, much less fluid was obtained than expected for his presenting symptoms and clinical course.