Focus on POCUS · Clinician education
Point-of-care ultrasound turns undifferentiated hypotension into a picture you can act on, at any bedside in the state.
Early recognition is the first link in the NMCSN activation pathway. POCUS is how a bedside clinician sees the physiology behind a shock call — pump, tank and pipes — before advanced imaging or transfer is available. This page covers the RUSH exam, the cardiac windows, and how to read the four shock states.
Pooled estimates from Keikha et al., Bulletin of Emergency and Trauma 2018;6(4):271–278 — a meta-analysis of five reports, two of them case reports. Accuracy is highest in hypovolaemic and obstructive shock and lowest in distributive and mixed presentations. Read these as a guide to where the protocol is strong and where it is blind, not as a performance guarantee.
Why it matters here
Hypotension drives a large share of rapid-response and ICU calls, and the physical examination alone is often misleading. Bedside ultrasound visualises the physiology directly, shortens time to diagnosis, and helps a clinician at a referring site decide quickly whether this is a shock call. In a hub-and-spoke system built on early recognition and rapid transfer, a shared POCUS approach gives every site — from a rural emergency department to the CVICU — one common language for the first minutes of shock care.
You never need a confirmed diagnosis to activate. Cardiogenic shock is frequently missed at the referring site; it presents as sepsis, acute kidney injury, or simply a patient who looks unwell. POCUS sharpens the picture, but undifferentiated shock is always reason enough to make the call. Nothing on this page should delay an activation.
The RUSH exam
A three-part physiologic roadmap — pump, tank, pipes — for classifying undifferentiated hypotension at the bedside. Start with the heart and the IVC, then tailor the remaining views to the clinical picture. Also remembered as HI-MAP: Heart, IVC, Morison's pouch and FAST, Aorta, Pneumothorax.
Window guide
Four windows used to interrogate the pump, and what each one is best at. Use this to orient before hands-on scanning; the images come from the probe in your hand.
Left atrium, mitral and aortic valves, left ventricle and the LVOT line up in one plane. First-line view for global function, for tracking a pericardial effusion posterior to the LV, and for a quick read on contractility.
Look for Effusion posterior to the LV, a poorly contracting dilated ventricle, or a small hyperdynamic chamber.
The same view on a compact point-of-care system — the machine the shock team actually carries to a rapid response. Depth and gain behave differently from cart-based echo, so learn to read both.
Look for The same anatomy at lower resolution. Set depth to include the descending aorta so you can distinguish pericardial effusion from pleural fluid.
Weighs right against left ventricular size. A dilated RV pressing on the septum raises pulmonary embolism or acute cor pulmonale. A useful fallback when the long-axis window is limited by body habitus or lung.
Look for RV to LV size ratio, septal flattening or a D-shaped LV, and regional wall motion.
Uses the liver as an acoustic window and keeps hands clear of the chest during compressions. The fastest look for pericardial effusion and gross function in a peri-arrest patient, and it sets up the IVC sweep for the tank.
Look for Circumferential effusion with RV collapse, gross biventricular function, then slide to the IVC.
A network library of de-identified teaching loops, captured at NMCSN scanning sessions with model consent, is in development. This guide is written to stand on its own until then.
Putting it together
Integrating findings across the three domains narrows undifferentiated hypotension to a working diagnosis and starts targeted therapy in the first minutes of resuscitation.
| Shock type | Pump | Tank | Pipes |
|---|---|---|---|
| Hypovolaemic | Hyperdynamic LV, small chamber | Small or collapsing IVC; free fluid or blood may be present | Look for aneurysm or ruptured aorta as the source |
| Cardiogenic | Poor LV function, dilated chamber | Plethoric IVC; B-lines and pulmonary oedema; effusions | Usually normal |
| Obstructive | Effusion with tamponade, or a strained dilated RV | Plethoric IVC; absent lung sliding in pneumothorax | DVT suggesting pulmonary embolism |
| Distributive | Hyperdynamic early; depressed in late sepsis | Variable IVC; peritoneal or pleural fluid as a source | Normal vessels; hunt for the source |
At the bedside
One repeatable sequence, adaptable to the patient in front of you.
Start with the pump. Phased-array probe on the heart — subxiphoid or parasternal first, whichever the patient's body allows. Rule in tamponade, gauge LV function, size the RV.
Assess the tank's volume. Sweep the IVC just below the diaphragm; note calibre and respiratory collapse to estimate filling and fluid tolerance.
Check the tank for leaks and overload. FAST views for free fluid, then anterior and lateral lung zones for B-lines, effusion and lung sliding.
Inspect the pipes. Abdominal aorta for aneurysm or dissection; add the proximal leg veins when pulmonary embolism is on the differential.
Integrate and act. Combine the three domains into a working category, document images to the chart, start targeted resuscitation — then reassess.
New to scanning? The step-by-step tutorial walks through all seven windows — where to put the probe, what you should see, what you are looking for, and where people go wrong — with a self-check question for each.
Evidence base
Core protocol descriptions and diagnostic-accuracy evidence for the RUSH exam.
Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam: Rapid Ultrasound in Shock in the evaluation of the critically ill. Emerg Med Clin North Am. 2010;28(1):29–56.
Perera P, Mailhot T, Riley D, Mandavia D. The RUSH exam 2012: Rapid Ultrasound in Shock in the evaluation of the critically ill patient. Ultrasound Clin. 2012;7(2):255–278.
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.
Keikha M, Salehi-Marzijarani M, Soldoozi Nejat R, et al. Diagnostic accuracy of Rapid Ultrasound in Shock (RUSH) exam: a systematic review and meta-analysis. Bull Emerg Trauma. 2018;6(4):271–278.
Ghane MR, Gharib M, Ebrahimi A, et al. Accuracy of early rapid ultrasound in shock (RUSH) examination performed by emergency physician for diagnosis of shock etiology in critically ill patients. J Emerg Trauma Shock. 2015;8(1):5–10.
Elbaih AH, Housseini AM, Khalifa MEM. Accuracy and outcome of rapid ultrasound in shock and hypotension in Egyptian polytrauma patients. Chin J Traumatol. 2018;21(3):156–162.
Shokoohi H, Boniface KS, Pourmand A, et al. Bedside ultrasound reduces diagnostic uncertainty and guides resuscitation in patients with undifferentiated hypotension. Crit Care Med. 2015;43(12):2562–2569.
Atkinson PR, Milne J, Diegelmann L, et al. Does point-of-care ultrasonography improve clinical outcomes in emergency department patients with undifferentiated hypotension? A randomised controlled trial (SHoC-ED). Ann Emerg Med. 2018;72(4):478–489.
Volpicelli G, Lamorte A, Tullio M, et al. Point-of-care multiorgan ultrasonography for the evaluation of undifferentiated hypotension in the emergency department. Intensive Care Med. 2013;39(7):1290–1298.
Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: a consensus statement of the American Society of Echocardiography and the American College of Emergency Physicians. J Am Soc Echocardiogr. 2010;23(12):1225–1230.
Via G, Hussain A, Wells M, et al. International evidence-based recommendations for focused cardiac ultrasound. J Am Soc Echocardiogr. 2014;27(7):683.e1–683.e33.
Get involved
Whether you want to host a scanning session at your site, train your team, or build ultrasound into your shock programme — we would like to hear from you.
