Pericardiocentesis - emergency drainage of the pericardial space
Pericardiocentesis is the percutaneous aspiration of fluid from the pericardial cavity to relieve cardiac tamponade and restore cardiac output. It is an uncommon, high‑acuity, low‑occurrence emergency procedure.
Where possible it should be performed under ultrasound guidance; blind (landmark) techniques are reserved only for immediate life‑threatening situations when ultrasound or surgical options are unavailable (Resus UK).
Clinical urgency
- Indication: haemodynamically significant pericardial effusion causing shock, severe hypotension, cardiac arrest or impending arrest; immediate decompression should not be delayed when tamponade is suspected (Resus UK).
- In traumatic haemopericardium with cardiac arrest or penetrating chest trauma, surgical options (resuscitative thoracotomy or mini‑thoracotomy) may be preferred depending on setting and expertise (Resus UK).
Pathophysiology - why tamponade occurs
- Normal pericardial fluid is small (approximately 20 ml).
- Tamponade results when accumulation of fluid (volume and/or rate) raises intrapericardial pressure enough to impair diastolic filling and reduce stroke volume.
- The rate of accumulation is critical: slow effusions may reach large volumes before causing tamponade, whereas rapid haemorrhage may cause severe tamponade with relatively small volumes (commonly cited ~200 ml for rapid collections, but clinical context varies).