When you are unsure of why your patient is hemodynamically unstable, use the RUSH exam: Rapid Ultrasound for Shock and Hypotension. Using the curvilinear or phased array probes, obtain these views to look for potential causes:

I. Pump: Evaluate the pericardium for Tamponade/Effusion, LV size for failure / cardiogenic shock, and RV size for failure/PE.
(1) Parasternal Sternal Long Axis view
(2) Apical 4-chamber view
II. Tank
(3) Inferior Vena Cava view
Collapsible → Hypovolemic shock
Plethoric → Cardiogenic shock/failure or Obstructive shock/PE
(4) Morrison pouch with hemothorax view
(5) Splenorenal recess with hemothorax view
(6) Bladder – Free fluid or blood
(8) & (9) Lung views – Tension Pneumothorax, effusion
III. Pipes
(7) Aortic views – AAA, rupture, dissection / Long and short-axis views
Note: If clinical suspicion is high, consider evaluating for ectopic pregnancy or DVT.