RUSH protocol: Rapid Ultrasound for Shock and Hypotension

Patients with hypotension or shock have high mortality rates, and traditional physical exam techniques can be misleading. Diagnosis and initial care must be accurate and prompt to optimize patient care. Ultrasound is ideal for the evaluation of critically ill patients in shock, and ACEP guidelines now delineate a new category of ultrasound (US)– “resuscitative.” Bedside US allows for direct visualization of pathology and differentiation of shock states.

The RUSH Protocol was first introduced in 2006 by Weingart SD et al, and later published in 2009. It was designed to be a rapid and easy to perform US protocol (<2 minutes) by most emergency physicians.

How do you perform the RUSH protocol?

What US probes do you need for the RUSH protocol?

• Phased-array probe (3.5 – 5 MHz)
• Linear probe (7.5 – 10 MHz)

What are the components of the RUSH protocol?

• The components of the RUSH exam are: Heart, Inferior vena cava (IVC), Morrison’s/FAST abdominal views, Aorta, and Pneumothorax (HI-MAP).
• A more simple method is to think of:
  • Pump (Heart): Tamponade, LVEF, and RV size
  • Tank (Intravascular): IVC, thoracic and abdominal compartments
  • Pipes (Large Arteries/Veins): Aorta and femoral/popliteal veins

Summary Table

(From Dr. Dina Seif’s handout at the Resuscitation 2013 conference) 

How do you evaluate the PUMP?

• Component: Heart (parasternal long axis view)
• Probe: Phased array probe (3.5 – 5 MHz)
• Location: Just left of the sternum, 3rd and 4th intercostal space
• Finding: Pericardial effusion (tamponade)

• Small effusions are best identified posterior to left ventricle (dependent portion of pericardium)
• Can find compression of the right ventricle (Singh S et al Sens 92%, Spec 100%, PPV 100%)

• Finding: Left ventricular ejection fraction estimation
  • Look at anterior leaflet of mitral valve, which should normally touch septum
  • <30% difference of LV size between systole and diastole indicates severely decreased LV function

• Finding: Right ventricular strain
  • Normally RV should be 60% of LV size (If RV = LV size, this is abnormal)
  • Lodato JC et al: If McConnell Sign (reduction in RV free wall motility with sparing of the apex) is present, specificity for PE is 96%, but sensitivity is 16%.

 

• Component: Heart (Subxiphoid)
• Probe: Phased array probe (3.5 – 5 MHz)
• Location: Subxiphoid, point toward left scapula

How do you evaluate the TANK?

• Component: Inferior Vena Cava
• Probe: Phased array probe (3.5 – 5 MHz)
• Location: Subxiphoid, slide to patient’s right
• Finding: Intravascular volume estimation

• IVC
• IVC >2 cm in diameter and inspiratory collapse less than 50% approximates CVP >10 cmH20
• Not applicable for intubated patients. Spontaneously breathing patients create negative intrathoracic pressure. ventilated patients create positive intrathoracic pressure.

• Component: FAST abdominal views
• Probe: Phased array probe (3.5 – 5 MHz)
• Location: Hepatorenal recess, Splenorenal recess, and bladder
• Finding: Internal blood loss

• Component: Pneumothorax
• Probe: Linear probe (7.5 – 10 MHz)
• Location: Midclavicular line, 3rd – 5th intercostal space
• Finding: Intrathoracic compromise
  • Normal: Should see lung sliding and comet tails. M-Mode will look like “waves on a beach”.
  • Pneumothorax present: NO lung sliding and NO comet tails. M-Mode will look like a “bar graph” (no beach).

 

How do you evaluate the PIPES?

• Component: Aorta
• Probe: Phased array probe (3.5 – 5 MHz)
• Location: Longitudinal and transverse views of aorta at 4 levels (infracardiac, suprarenal, infrarenal, and right at the iliac bifurcation)
  • Measurement >3 cm is abnormal. If >5 cm consider ruptured AAA if no other cause found.
  • Most AAAs located below the renal arteries

Summary

The RUSH protocol is to medical patients what the EFAST exam is to trauma patients.

Special Thank You

I would like to thank Dr. Craig Sisson, Ultrasound Director at UTHSCSA in San Antonio, TX for all the ultrasound images used in this post as well as his countless hours of teaching ultrasound.

References

1. Jones AE et al. Randomized, Controlled Trial of Immediate Versus Delayed Goal-Directed ultrasound to Identify the Cause of Nontraumatic Hypotension in emergency Department Patients. Crit Care Med 2004 Aug; 32 (8): 1703–8. PMID:15286547
2. Perera P et al. The RUSH Exam: Rapid Ultrasound in Shock in the Evaluation of the Critically Ill. Emerg Med Clin N Am 2010; 28: 29–56. PMID:19945597
3. Rose JS et al. The UHP Ultrasound Protocol: A Novel Ultrasound Approach to the Empiric Evaluation of the Undifferentiated Hypotensive Patient. Am J Emerg Med 2001; 19: 299–302. PMID: 11447518
4. Weingart DS. EMCrit Blog

 

Author information

The post RUSH protocol: Rapid Ultrasound for Shock and Hypotension appeared first on ALiEM.