Ultrasound: In Shock and Hypotension


  • A bedside ultrasound paradigm for differentiating differentiating shock states (cardiogenic, obstructive, hypovolemic, distributive)
    • Tailor specific protocol to the patient at hand
  • RUSH Protocol was conceived in 2008 and looks are 3 basic aspects of physiology[1][2]
  1. The Pump
  2. The Tank
  3. The Pipes

The Protocol

Step 1: The Pump
Step 2: The Tank
Step 3: The Pipes

Rapid Ultrasound for Shock and Hypotension(RUSH) using the HI-MAP approach[3]

  • H - Heart (parasternal and four-chamber views)
  • I - Inferior Vena Cava (for volume responsiveness)
  • M - Morison’s pouch (i.e., FAST exam) and views of thorax (looking for free fluid)
  • A - Aortic Aneurysm (ruptured abdominal aneurysm)
  • P - Pneumothorax (i.e., Tension pneumothorax)


Technique: see Cardiac ultrasound

  • Pericardial Effusion
    • May be most obvious with PLAX or subxiphoid views[4]
      • In PLAX, pericardial fluid is anterior to descending aorta, while pleural fluid is posterior to it
    • Isolated anterior anechoic areas may be an anterior fat pad
    • Assess for tamponade physiology including diastolic collapse of RA or RV; see Pericardial effusion and tamponade
  • LV squeeze
    • PLAX and PSAX are good views to estimate contractility
    • Change in size <30% between sys and dia = poor LV function
    • Hyperdynamicity, as determined by walls moving >90% or touching at end of systole, may indicate hypovolemia or sepsis
    • May direct fluid therapy
  • RV strain
    • In 4-chamber view, RV should be <60% of LV; if dilated/larger think RV strain
    • While chronic RV strain (ex. cor pulmonale) may cause RVH, massive PE will not have time to cause RVH


Technique: see IVC ultrasound

  • Measure 2cm caudally from RA-IVC junction
  • If IVC <2.1cm and collapses >50% on inspiration then RAP/CVP is low[5]
  • If IVC >2.1cm and collapses <50% then RAP/CVP is high
    • Suggests fluid unresponsive; patient requires inotropes
  • IVC measurements may be altered in patients receiving vasoactive medications or positive pressure ventilation


Technique: see FAST exam

  • Assess for free fluid
    • Morison's pouch (hepatorenal space)
    • Splenorenal
    • Bladder, including retrovesicular space
    • As part of E-FAST, when in hepatorenal or splenorenal views, aim/slide probe above diaphragm to assess for pleural effusion
  • Note that while ascitic fluid often appears anechoic, blood may appear with mixed echogenicity due to the presence of clots


Technique: see Aortic ultrasound

  • Steady pressure with probe can displace bowel gas, improving view
  • If >5cm assume ruptured AAA until proven otherwise
  • In PLAX, aortic root >3.8cm may be seen in proximal aortic dissection or aortic aneurysm[6]


Technique: see Ultrasound: Lungs

  • Assess for subpleural interstitial edema
    • Look for multiple comet tail artifacts or "B lines"(a few, 3-4, are OK)
      • If multiple found, there is interstitial pulmonary edema
  • Assess for pneumothorax
    • Scan longitudinally in anterior 2nd-3rd IC space, mid-clavicular line, looking for echogenic pleural line
    • On M-mode, look for lack of pleural sliding, aka "Barcode sign"
    • Presence of lung point is highly specific for PTX


Classic Ultrasound Findings For Critically Ill Patients

Disease IVC Cardiac Lung (Phased Array) Lung (Linear)
MI Focal WMA
Mod/Poor squeeze
NL or B-lines Sliding
Tamponade RA collapse with filling
RV collapse with filling
NL Sliding
PTX NL or Hyperdynamic Lung point
Consolidated lung
Absent lung sliding
Sepsis Hyperdynamic squeeze NL (see pneumonia) Sliding
Pneumonia NL or ↓ Hyperdynamic squeeze Unilateral B-lines Sliding
Decompensated HF Mod/Poor squeeze Bilateral B-lines Sliding
McConnell's sign
NL or Unilateral B-lines Sliding

See Also

External Links


  1. Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll. Emerg Med Clin North Am. 2010 Feb;28(1):29-56, vii. doi: 10.1016/j.emc.2009.09.010. PMID: 19945597.
  2. Weingart - https://emcrit.org/rush-exam/
  3. Dina Seif. Bedside Ultrasound in Resuscitation and the Rapid Ultrasound in Shock Protocol Critical Care Research and Practice Vol 2012 http://downloads.hindawi.com/journals/ccrp/2012/503254.pdf
  4. Alerhand S, Carter JM. What echocardiographic findings suggest a pericardial effusion is causing tamponade? Am J Emerg Med. 2019 Feb;37(2):321-326. doi: 10.1016/j.ajem.2018.11.004. Epub 2018 Nov 17. PMID: 30471929.
  5. Rudski LG, Lai WW, Afilalo J, Hua L, Handschumacher MD, Chandrasekaran K, Solomon SD, Louie EK, Schiller NB. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010 Jul;23(7):685-713; quiz 786-8. doi: 10.1016/j.echo.2010.05.010. PMID: 20620859.
  6. Seif D, Perera P, Mailhot T, Riley D, Mandavia D. Bedside ultrasound in resuscitation and the rapid ultrasound in shock protocol. Crit Care Res Pract. 2012;2012:503254. doi: 10.1155/2012/503254. Epub 2012 Oct 24. PMID: 23133747; PMCID: PMC3485910.