• Cardiac tamponade (Chapter 54). Echocardiography must be done first to confirm the presence of a pericardial effusion unless there is cardiac arrest from presumed tamponade.
• Pericardial effusion due to suspected bacterial pericarditis (p. 342).
• To establish the cause of a moderate or large pericardial effusion, when other investigations have failed to do so.

Contraindications

• Pericardial effusion of less than 2cm thickness without haemodynamic compromise: discuss management with a cardiologist.
• Bleeding disorder/coagulopathy (including platelet count <50×10⁹/L, INR >1.5, or receiving oral anticoagulant or anticoagulant-dose heparin): discuss management with a haematologist.
• Associated aortic dissection or myocardial rupture: drainage may aggravate bleeding.

Potential complications (incidence in patients without contraindications <5%)

• Penetration of a cardiac chamber (usually right ventricle) (may result in acute tamponade).
• Laceration of an artery (coronary, left internal thoracic, intercostal, intraabdominal (may result in acute tamponade)).
• Arrhythmia
• Pneumothorax
• Perforation of stomach or colon (with subcostal approach)
• Vasovagal reaction
• Failure of the procedure
• Infection