BloodSweatxED
PRN Education · No. 014 · POCUS Series

RUSH
Exam.

Rapid Ultrasound for Shock and Hypotension takes the undifferentiated hypotensive patient and sorts them into a shock category in about two minutes — without pausing the resuscitation. Three questions: how's the pump, how full is the tank, are the pipes intact?

RUSH is not a new scan — it's a sequence of scans you already know, assembled into one decision framework.

Source

Curated from the POCUS 101 RUSH Exam Ultrasound Protocol: Step-By-Step Guide. Their walkthrough of each component with matched clips is the best way to see the framework assembled.

When to scan

One indication, one caution

Reach for the probe

  • Undifferentiated shock or unexplained hypotension
  • Sorting the four shock categories at the bedside
  • Guiding early resuscitation: fluids vs. pressors vs. procedure
  • Reassessing the patient who isn't responding as expected
  • Peri-arrest evaluation for reversible causes

Know the limits

  • RUSH narrows and prioritizes — it does not replace the full workup, labs, or definitive imaging.
  • Shock is often mixed (e.g. septic plus cardiogenic). The exam finds contributors; it does not always crown a single cause.
  • Each component carries its own pitfalls — see the linked individual exams. Garbage views yield garbage categories.

The framework

Pump · Tank · Pipes

Pump

The heart

Effusion / tamponade, global squeeze (EF), and RV size. See TTE Basics and Echo for PE.

Tank

The volume

IVC fullness, plus the eFAST spaces and lungs for where volume has gone or leaked. See Lung and eFAST.

Pipes

The vessels

Aorta for aneurysm/rupture, and the leg veins for DVT. See Aorta and DVT.

The scan

Three components, in sequence
RUSH · PUMP / TANK / PIPES PUMP • Pericardial effusion   / tamponade • LV contractility (EF) • RV strain (PE) views: PLAX, A4C, subxiphoid TANK • IVC size + collapse • Lungs: B-lines,   PTX, effusion • eFAST: free fluid views: IVC, lung zones, FAST spaces PIPES • Aorta: AAA   / rupture • Femoral + popliteal   veins: DVT views: aorta sweep, 2-region compression
Fig. 1 — The RUSH framework. Each column is a scan you already know; RUSH is the order and the synthesis.

Pump — the heart

Parasternal, apical, and subxiphoid cardiac views

Answer three questions in order of lethality: Is there a pericardial effusion with tamponade? Is the LV hyperdynamic, normal, or severely reduced? Is the RV enlarged (acute cor pulmonale suggesting massive PE)?

  • Tamponade → obstructive shock, pericardiocentesis
  • Poor squeeze → cardiogenic shock, pressors/inotropes, careful with fluids
  • Big RV + D-sign → consider massive PE

Tank — the volume

IVC, then lungs, then the FAST windows

The IVC estimates the tank's fullness: flat and collapsing suggests an empty tank (hypovolemic/distributive), plump and fixed suggests a full or obstructed one (cardiogenic/obstructive). Then check whether the tank is leaking (free fluid on FAST) or overflowing (diffuse B-lines) or compromised (pneumothorax, large effusion).

Synthesis: a flat IVC with a hyperdynamic heart points toward hypovolemia or distributive shock; a plump IVC with a poor squeeze points toward the pump.

Pipes — the vessels

Abdominal aorta sweep, then leg vein compression

Interrogate the aorta for an aneurysm (a ruptured AAA is a rapidly fatal cause of hypotension), then the femoral and popliteal veins for DVT — which, with a strained RV on the pump exam, supports massive PE as the cause.

Don't skip the pipes. A ruptured AAA or a massive PE can present as "undifferentiated" shock and is missed if the exam stops at the heart and IVC.

Reading the pattern

Four shock categories
Shock typePumpTank (IVC)Pipes / other
HypovolemicHyperdynamic, small chambersflat, collapsingFree fluid (hemorrhage) or normal
Distributive (septic)Hyperdynamic early; may depress lateflat / normalSource-dependent; lungs may show pneumonia
CardiogenicPoor contractilityplump, fixedDiffuse B-lines (pulmonary edema)
ObstructiveTamponade, or big RV (PE)plump, fixedEffusion; PTX; DVT + RV strain = PE

The categories overlap and shock is often mixed — use the pattern to prioritize the next intervention, then reassess. RUSH is a starting hypothesis, not a final diagnosis.

Pearls & pitfalls

Where this framework goes wrong
Pearl

Lethal-first ordering

Structure the pump exam by what kills fastest: tamponade, then pump failure, then RV strain. You can act on tamponade before you've finished the rest of the scan.

Pearl

The IVC is a piece, not the answer

IVC assessment is crude and confounded by ventilation, PEEP, and RV failure. Read it alongside the heart and lungs, never in isolation, and prefer trends over a single still.

Pitfall

Anchoring on one cause

Finding a flat IVC and stopping there misses the concurrent tamponade or the ruptured AAA. Complete all three components before committing to a category.

Pitfall

Mixed shock read as pure

A septic patient can also have cardiac dysfunction; a trauma patient can have both hemorrhage and tension physiology. Let the exam show more than one contributor.

Pearl

Don't interrupt the resuscitation

RUSH is designed to run alongside ongoing care. Scan during natural pauses, keep it under a couple of minutes, and never let the probe delay compressions, blood, or the airway.

Pearl

Repeat after every intervention

The value is in the trend. Rescan the pump and tank after the fluid bolus, the pressor, or the pericardiocentesis to confirm the response and catch the evolving second cause.

Sample Epic documentation

Copy · edit · attest

A starting template for a RUSH procedure note. Fields in blue are wildcards to complete. Build it as a SmartPhrase, then edit every field to match the actual study.

.pocusRUSH
POINT-OF-CARE ULTRASOUND: RUSH EXAM

Indication: undifferentiated shock / hypotension [***]
Exam type: Focused / limited, bedside, during resuscitation
Operator: @ME@   Interpretation: independent, real-time
Probe: phased array + curvilinear
Consent: emergent, not obtained / [***]

PUMP (heart)
- Pericardial effusion: {none : present [***], tamponade physiology {no : yes}}
- LV function: {hyperdynamic : normal : moderately reduced : severely reduced}
- RV size: {normal : enlarged, D-sign {no : yes}}

TANK (volume)
- IVC: {flat, >50% collapse : normal : plethoric, <50% collapse}
- Lungs: {A-lines / dry : diffuse B-lines : effusion : pneumothorax [side ***]}
- FAST windows: {no free fluid : free fluid [***]}

PIPES (vessels)
- Aorta: {normal caliber <3 cm : aneurysm [*** cm]}
- Leg veins: {compressible / no DVT : non-compressible / DVT [side ***] : not assessed}

IMAGE QUALITY: adequate / limited by [***]
Images saved and archived to [PACS / Qpath / ***].

IMPRESSION: findings most consistent with {hypovolemic : distributive :
cardiogenic : obstructive : mixed} shock. [***]
Resuscitation adjusted accordingly; reassessment planned.

I personally performed and interpreted this study in real time.
Electronically signed: @ME@  @TD@ @NOW@

Sample template only — not a validated institutional SmartPhrase. Verify wording, image-archival, and attestation requirements against your department's POCUS credentialing, coding, and compliance policies before clinical use. Documentation supports, but does not replace, the medical record and QA workflow.

PRN Education · POCUS Series

Keep scanning