The parietal pericardium is a sac that encloses the heart, it usually contains less than 50ml of a serous fluid that acts to lubricate the sac around contracting heart. The sac is relatively rigid and when filled with excessive fluid, it can compress the cardiac chambers, compromising filling pressure and contractility resulting in significant unstable vital signs including severe tachycardia and hypotension, known as cardiac tamponade. This excessive fluid can be hemorrhagic from trauma, aneurysmal rupture or aortic dissection, or due to medical etiologies such as cancer, nephrotic syndrome, tuberculosis, etc.
Patients typically present with shortness of breath, hypotension and clear lungs. Physical exam is often unreliable for diagnosis, but the classic Beck Triad includes increased JVD, hypotension and muffled heart sounds. Pulsus paradoxus is also a common finding.
Bedside echocardiography is the most important imaging for diagnosis of cardiac tamponade. Findings include pericardial fluid with diagnostic collapse of the right atrium and ventricle. CXR may show an enlarged cardiac silhouette (the “water-bottle shaped heart”). However, acute causes of cardiac tamponade may present without an enlarged cardiac silhouette. EKG can show low voltage and electrical alternans, although these are not very specific for the diagnosis of cardiac tamponade.
Pericardiocentesis can be performed via a subcostal, left parasternal or apical approach. This module focuses on the subcostal approach, where a needle is inserted from the subcostal approach into the anterior aspect of the pericardium.
This module addresses emergent pericardiocentesis, in the setting of an unstable patient with cardiac tamponade. If a patient is stable, cardiology or cardiothoracic surgery should be consulted for OR percutaneous drainage or placement of a pericardial window.
- Patient positioning and preparation
- Insertion of needle
- Aspiration of fluid
- Removal of needle
- Aftercare including confirmation of removal of pericardial fluid, resuscitation and chest X-ray
For a subcostal pericardiocentesis, a needle is inserted under the costal margin into the anterior surface of the pericardium to drain the fluid. The liver, lung and diaphragm are also located in the area and can be damaged during the procedure, however generally the emergence of the procedure takes precedence over these risks.
Cardiac tamponade due to either traumatic or medical etiologies.
There are no absolute contraindications to pericardiocentesis when it is indicated as an emergency. However, if a patient is stable for a more definitive treatment such as pericardial window or OR percutaneous drainage, these alternative treatments should be considered.
Relative contraindications include coagulopathy, when an effusion is associated with aortic dissection of myocardial rupture. However, if a patient is severely unstable the risks of pericardiocentesis to improve hemodynamic stability may outweigh the benefits.
As this is an emergent procedure there is no specific local or general anesthetic provided.
Patients with cardiac tamponade are admitted to the hospital after pericardiocentesis. Emergent cardiology or cardiothoracic surgery consultation is necessary to determine if pericardial window is indicated to prevent recurrent cardiac tamponade.
Immediate complications include cardiac arrest, cardiac chamber laceration, coronary vessel laceration, lung laceration, pneumothorax, dysrhythmia, air embolism, pneumopericardium and failure to relieve the tamponade.
Additionally, the needle may pass through the liver to reach the pericardium, but the rate of significant hemorrhage is low. Perforation of hollow viscus is theoretically possible but rarely reported.
Delayed complications include pulmonary edema and pericardia-pleural shunt.
- Garg, M and Ufberg J (2013) Cardiovascular and Neurologic Oncologic Emergencies In James Adam (Ed.) Emergency Medicine: Clinical Essentials (pp1679-1684). Philadephia, PA: Elsevier/Saunders.
- Heffner, Alan C. Emergency pericardiocentesis. UpToDate, 23 June 2015. Web. 4 Dec 2015.