Is there a pericardial effusion?

Presence, size and distribution (circumferential or loculated) of pericardial fluid

Be aware that a pleural effusion or dilated right ventricle may be misdiagnosed on echocardiography as a pericardial effusion

Are there echocardiographic signs of cardiac tamponade in a spontaneously breathing subject?

Diastolic collapse of the free wall of the right ventricle

A fall in mitral inflow velocity or aortic velocity by >25% on inspiration

Engorgement of the inferior vena cava with no respiratory variation

Reduction in LV cavity size on inspiration

Is pericardiocentesis feasible and safe? Which approach is preferred? (Chapter120)

Subcostal drainage (Chapter 120) is safest and there should usually be >20 mm fluid in the subcostal approach.

Drainage may be difficult if the fluid is dense or there are multiple loculations.

Echocardiography can be used to guide pericardiocentesis by confirming the position of the needle tip from the presence of intra-pericardial bubbles on re-injection of the initial fluid sampled, and should be repeated after drainage to assess the size of any residual effusion.