In this case, as the patient had recent thoracic surgery, the presence of both a pericardial effusion and the pleural effusion raised concern about a possible fistula formation. After operative report review, the thoracic surgeon felt this was unlikely. As either or both the pericardial and the pleural effusion could have theoretically been causing the patient’s hemodynamic instability, both a pericardiocentesis and a thoracentesis were considered. Ultimately, the tube thoracostomy was a faster and lower risk procedure and resolved the patient’s tamponade physiology. The pericardial effusion was determined to be physiologic.  

The benefit of using POCUS to establish a diagnosis in a patient with hemodynamic instability or respiratory distress is multifold and has been shown to significantly affect immediate patient care. The bedside lung ultrasound in emergency (BLUE) protocol describes investigation of thoracic and pulmonary pathology using POCUS reliably to  provide an accurate diagnosis within three minutes.² POCUS also enables the provider to re-assess the patient’s hemodynamics, cardiac function, and pulmonary pathology throughout a resuscitation and after specific interventions, such as in this case where the patient is seen to have resolution of his tamponade after chest thoracostomy, avoiding potential further diagnostic uncertainty regarding the etiology of his tamponade physiology, or hemodynamic collapse should he have been laid supine for additional imaging.  

We have described an uncommon case of tamponade physiology caused by the lesser-known tension hydrothorax and not the patient’s associated pericardial effusion. This patient’s POCUS-guided resuscitation was followed by clinical and sonographic resolution of cardiac tamponade after tube thoracostomy. 

Teaching Points: 

• Tension hydrothorax resulting from a pleural effusion is a rare manifestation of tension physiology. 

• Consider extracardiac causes of tamponade in patients without pericardial effusion or small pericardial effusion unlikely to have rapidly developed, and treat the underlying cause of obstructive shock. 

• POCUS allows for efficient, real-time diagnosis of life-threatening conditions in both patients with hemodynamic instability and respiratory distress and allows clinicians to monitor response to resuscitation after intervention. 

Dr. Lynch is an Advanced Emergency Ultrasound Fellow at UPMC, where she recently graduated from emergency medicine residency as a chief resident. 

Dr. Lovallo is an associate professor of emergency medicine at the University of Pittsburgh School of Medicine and Medical Director of the Freedom House 2.0 Program.  

Ms. Bulova is a current third-year medical student at the University of Pittsburgh School of Medicine. 

References 

1. Gelmann D, Slagle D, Seaback J, et al. Advanced critical care ultrasound: use of mitral valve inflow velocity variation in evaluation of cardiac tamponade. https://www.emra.org/emresident/article/CCUS-mv-variation. Published June 12, 2024. Accessed December 6, 2024.
2. Lichtenstein DA, Mezière GA. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol [correction appears in Chest. 2013;144(2):721]. Chest. 2008;134(1):117-125.