Table 3.

SHOCK: a practical mnemonic for the differential diagnosis of the spectrum of hemodynamic instability, shock, and pulseless electrical activity arrest

Type of shock	Goal-directed echocardiographic features
Septic/distributive	Less severe shock - hyperdynamic. Severe shock - can be hypodynamic
Hypovolemic	Collapsing IVC, small ventricles, may be hyperdynamic
Obstructive	Tamponade: pericardial effusion, tamponade physiology
	Pulmonary embolism: large RV, septal shift/diastolic flattening
Cardiogenic	Decreased LV (±RV) function, dilated ventricles
K	Combinations (for example, septic plus hypovolemic, septic plus cardiogenic, and so on)
	Other kinds (adrenal insufficiency, neurogenic, and so on). This broader category is raised by the question ‘What does not fit?’

IVC, inferior vena cava; LV, left ventricle; RV, right ventricle.