RUSH

Here’s a concise summary and breakdown of the AEUS Narrated Lecture on the RUSH exam (Rapid Ultrasound for Shock and Hypotension) for quick study or teaching:

Overview:

RUSH Protocol is a point-of-care ultrasound (POCUS) tool used in undifferentiated shock (non-trauma) to rapidly assess the cause and guide early intervention. It is structured and efficient, aiming to identify life-threatening conditions quickly.

Learning Objectives:

By the end of the session, you should be able to:

Identify indications for performing a RUSH exam.
List and perform the components of a RUSH exam.
Interpret key sonographic findings in the context of shock.

1. Indications for RUSH Exam:

Hypotension
Altered mental status of unclear etiology
Syncope or collapse
Tachycardia without a clear cause
Concern for undifferentiated shock (e.g., obstructive, cardiogenic, hypovolemic, distributive)

2. Components of the RUSH Exam:

The RUSH exam can be remembered with the mnemonic: HI-MAP or Pump, Tank, Pipes.

Pump (Heart)

Parasternal long/short axis
Apical 4-chamber
Subxiphoid
Assess:
- LV contractility (EF)
- RV strain (suggests PE)
- Pericardial effusion (tamponade)

Tank (Volume status)

IVC diameter and respiratory variation
Free fluid in Morison’s pouch, splenorenal space, pelvis
Lung ultrasound:
- B-lines (pulmonary edema)
- Absent lung sliding (pneumothorax)

Pipes (Vessels)

Aorta: look for aneurysm or dissection
Femoral/Popliteal veins: compressibility to rule out DVT (suggests PE if positive)

3. Image Interpretation Highlights:

Pericardial effusion with diastolic RV collapse → Cardiac tamponade
Hyperdynamic LV with collapsed IVC → Hypovolemic or distributive shock
Poor LV contractility → Cardiogenic shock
Dilated RV with septal bowing and normal LV → Obstructive shock (e.g., massive PE)
Enlarged aorta with mural thrombus or flap → AAA or dissection

Clinical Impact:

Expedites diagnosis and management
Improves triage decisions
Reduces time to definitive therapy

https://www.youtube.com/watch?v=1rU6hOusHA0&t=1s

Here is a concise summary of teaching points from the narrated AEUS lecture on the RUSH (Rapid Ultrasound in Shock and Hypotension) protocol:

Core Teaching Points

Purpose of Resuscitative Ultrasound (RUSH)

Used in undifferentiated shock to rapidly identify life-threatening causes and guide early treatment.
Shock is a mismatch between oxygen supply and demand and must be quickly assessed and reversed.
POCUS provides real-time physiologic insights when history or physical exam is limited.

Structured Approach: HI-MAP Mnemonic

Helps evaluate:

H: Heart (contractility, tamponade, RV strain)
I: IVC (volume status, collapsibility)
M: Morrison’s pouch and abdomen (free fluid, hemorrhage)
A: Aorta (AAA, dissection)
P: Pulmonary (pneumothorax, B-lines, consolidation)

Cardiac Assessment

Look for pericardial effusion → may suggest tamponade (obstructive shock)
- Look for RV collapse in diastole, swinging heart motion.
RV strain → suggests PE
- RV:LV ≥ 1:1 is concerning; look for septal bowing.
LV function (qualitative): assess contractility
- Poor squeeze → cardiogenic shock
- Hyperdynamic LV → early sepsis or hypovolemia

IVC Evaluation

Assess diameter and collapsibility
- <1.5 cm = volume down
- 2.5 cm = volume up
Collapsibility Index: (max - min)/max
- 50% = low CVP → fluid responsive
- <50% = high CVP → likely not fluid responsive
Reverse interpretation in ventilated patients

Abdominal and Aortic Views

Morrison’s pouch, pelvis, splenorenal recess → look for free fluid = possible hemorrhage
Evaluate aorta from epigastrium to bifurcation
- AAA = aorta >3 cm; >5 cm = rupture risk
- 50% of AAAs are infrarenal

Pulmonary Ultrasound

Evaluate for pneumothorax: absence of lung sliding
Identify B-lines = pulmonary edema
Identify hepatized lung = pneumonia/consolidation

DVT Scan (Optional Add-on)

If RV strain or PE suspected, check common femoral vein for DVT (non-compressibility = positive DVT)

Case-Based Pearls

Case 1: Hypovolemic Shock

Hyperdynamic LV + Flat, collapsible IVC → initiate fluids
No abdominal fluid or AAA → suggests volume loss (dehydration, sepsis, etc.)

Case 2: Cardiogenic Shock

Poor LV squeeze + Plethoric IVC + B-lines → CHF
Management: diuresis, afterload reduction, noninvasive ventilation

Summary Points

RUSH exam is a powerful diagnostic tool in hypotension.
Use HI-MAP to evaluate shock systematically, but flexibility in scan order is key.
Findings guide immediate intervention before labs or imaging return.
Serial ultrasound can track response to therapy.

The correct answer is: Hypovolemic shock.

Here's why:

Collapsible IVC → Suggests low central venous pressure (CVP), consistent with volume depletion.
Hyperdynamic heart → Seen in early stages of hypovolemia or sepsis, where the heart is compensating for low preload.
Hepatization of the lung → This usually indicates consolidation (e.g., pneumonia), which can lead to sepsis and secondarily to hypovolemic or distributive shock.

However, when combined with collapsible IVC and hyperdynamic heart, the overall picture most closely aligns with hypovolemic shock, especially in the early phase of septic hypovolemia (fluid losses due to capillary leak or insensible losses in severe infection).

If the stem had said B-lines instead of hepatization, cardiogenic shock would be more likely. But hepatization alone does not equal pulmonary edema.

Final Answer: Hypovolemic

actually septic distributive shock?

Correct Answer: Distributive Shock (Septic Shock)

Why?

Collapsible IVC → Low intravascular volume or low CVP, common in early sepsis due to vasodilation and capillary leak.

Hyperdynamic heart → Classic in early septic shock, as the heart tries to compensate for decreased systemic vascular resistance.

Hepatization of the lung → Suggests consolidation, as seen in pneumonia, which is a common source of sepsis.

Teaching Pearl:

In early septic shock, patients may appear volume-depleted (collapsible IVC) and hyperdynamic as part of the body's compensatory response.

Pulmonary consolidation helps localize the source to the lungs — making sepsis from pneumonia the likely culprit.

Thanks again — great clinical reasoning!

Correct diagnosis: Distributive shock (septic shock from pneumonia).

Incorrect! This patient likely has septic (distributive) shock from pneumonia

Correct! IVC gives the providers and idea about volume responsiveness but not volume status. Remember the IVC has many external factors that effect it. IVC > 50 collapsible is likely volume responsive. A plethoric IVC does not mean the patient does not need fluids.

Key Clarification:

IVC collapsibility is best used to assess volume responsiveness — Will the patient increase their cardiac output if given fluids?
It does not reliably measure absolute volume status.

Clinical Reminders:

IVC >50% collapsible (in spontaneous breathing) → likely fluid responsive.
Plethoric IVC (dilated, non-collapsible) → May indicate high right-sided pressures, but not always a contraindication to fluids.
- Example: Obstructive shock (e.g., tamponade, PE)
- Cardiogenic shock — patient may still benefit from careful volume loading in specific contexts (e.g., RV infarct).

Pearl:

Always integrate IVC findings with cardiac ultrasound, lung views, clinical exam, and the overall clinical picture.

Incorrect! The gestalt of LV function is the aim of POCUS one

does not need to calculate EF but rather estimate normal, depressed, or severely depressed.

Correct! In mechanically ventilated patients, increased intrathoracic pressure during inspiration causes a decrease in venous return to the right atrium and a transient increase in IVC diameter and collapse during expiration.

Explanation – IVC in Ventilated Patients:

In spontaneously breathing patients, the IVC collapses during inspiration due to negative intrathoracic pressure pulling blood into the chest.

In mechanically ventilated patients, the physiology is reversed:

Positive pressure increases intrathoracic pressure during inspiration, which impedes venous return.
As a result, the IVC distends during inspiration and may collapse during expiration.

Summary Table:

Breathing Type	IVC Collapses During	IVC Distends During
Spontaneous breathing	Inspiration	Expiration
Mechanical ventilation	Expiration	Inspiration

Correct! Circumferential effusion, impaired RV filling, Obstructed outflow of the RV, and hemodynamic compromise. To assist with determining phase of the cardiac cycle consider evaluating systolic vs. diastolic phases with M-mode: Position in PSL view with M-mode line through where RV appears to collapse Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS) Correct! Circumferential effusion, impaired RV filling, Obstructed outflow of the RV, and hemodynamic compromise. To assist with determining phase of the cardiac cycle consider evaluating systolic vs. diastolic phases with M-mode: Position in PSL view with M-mode line through where RV appears to collapse Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS) Correct! Circumferential effusion, impaired RV filling, Obstructed outflow of the RV, and hemodynamic compromise.

To assist with determining phase of the cardiac cycle consider evaluating systolic vs. diastolic phases with M-mode: Position in PSL view with M-mode line through where RV appears to collapse Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS) Correct! Circumferential effusion, impaired RV filling, Obstructed outflow of the RV, and hemodynamic compromise. To assist with determining phase of the cardiac cycle consider evaluating systolic vs. diastolic phases with M-mode: Position in PSL view with M-mode line through where RV appears to collapse Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS) Correct! Circumferential effusion, impaired RV filling, Obstructed outflow of the RV, and hemodynamic compromise. To assist with determining phase of the cardiac cycle consider evaluating systolic vs. diastolic phases with M-mode: Position in PSL view with M-mode line through where RV appears to collapse Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS)

Key Diagnostic Features of Tamponade (Ultrasound)

Circumferential Pericardial Effusion
- Must surround the heart (not loculated).
Impaired Right Heart Filling
- Seen as:
  - RA systolic collapse
  - RV diastolic collapse ← most specific
  - Plethoric, non-collapsible IVC
Obstructed RV Outflow
- Leads to reduced preload → decreased cardiac output → hemodynamic compromise
Hemodynamic Compromise

Hypotension, tachycardia, pulsus paradoxus, altered mental status, etc.

Advanced Tip: Using M-mode to Confirm Diastolic RV Collapse

View: Parasternal long axis (PSL)
M-mode line: Through RV free wall where it collapses
Also pass through: Tip of anterior mitral valve leaflet
- Why? Because the anterior MV leaflet hits the septum in diastole
- This gives you a timing marker to identify collapse in diastole (tamponade-specific)

This is just like EPSS (E-point septal separation), but applied for tamponade physiology.

If you're not sure when RV collapse is occurring — use M-mode to time it relative to MV motion. If collapse aligns with diastole, that's tamponade.

Correct! While OB and DVT can be added to a protocol to further narrow the diagnosis they are not part of the standard approach HI MAP Heart, IVC, Morissons Pouch, Aorta, Pneumothorax We often expand PTX to include Pulmonary edema and pleural effusion Correct! While OB and DVT can be added to a protocol to further narrow the diagnosis they are not part of the standard approach HI MAP Heart, IVC, Morissons Pouch, Aorta, Pneumothorax We often expand PTX to include Pulmonary edema and pleural effusion Correct! While OB and DVT can be added to a protocol to further narrow the diagnosis they are not part of the standard approach HI MAP Heart, IVC, Morissons Pouch, Aorta, Pneumothorax

We often expand PTX to include Pulmonary edema and pleural effusion Incorrect! While OB and DVT can be added to a protocol to further narrow the diagnosis they are not part of the standard approach HI MAP Heart, IVC, Morissons Pouch, Aorta, Pneumothorax We often expand PTX to include Pulmonary edema and pleural effusion Correct! While OB and DVT can be added to a protocol to further narrow the diagnosis they are not part of the standard approach HI MAP Heart, IVC, Morissons Pouch, Aorta, Pneumothorax We often expand PTX to include Pulmonary edema and pleural effusion

Correct Answers for HI-MAP Protocol Components:

Cardiac
IVC
Aorta
Lungs
FAST

HI-MAP Breakdown (Mnemonic for Hypotensive Ultrasound Evaluation):

Letter	Meaning	What it Assesses
H	Heart (Cardiac)	LV function, RV strain, pericardial effusion
I	IVC	Volume status, fluid responsiveness
M	Morrison’s pouch	Part of FAST exam – free fluid (hemoperitoneum)
A	Aorta	Abdominal aortic aneurysm or dissection
P	Pneumothorax/Lungs	Pneumothorax, B-lines (pulmonary edema), effusion

Correct! 3 cm outer to outer (to avoid measuring false lumen) AAA Review: Infrarenal diameter >3cm or >50% increase in size of diameter 85% of cases are infrarenal Male to Female ratio is 4:1 Rupture Risk <4cm: low risk for rupture 4-5cm: 5 year risk 3-12% >5cm: 25-41% Rupture possible at any size, most commonly >5cm Mortality with rupture: 85-90%

not electrical alternans

RV diastolic

Not RV systolic

Pericardial effusion

RA collapse

plethoric IVC

Hemodynamic collapse

not DVT

Uterus

Cardiac

Aorta

FAST

IVC

not lungs

Core ultrasound

SamuelYHuang

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