Ultrasound: In Shock and Hypotension

Background

• Several techniques are available for differentiating shock states
• RUSH Protocol was conceived in 2008 and looks are 3 basic aspects of physiology

1. The Pump
   1. RV:LV
   2. Squeeze
   3. Pericardial effusion
2. The Tank
   1. IVC
   2. Pleural effusions
   3. Pulmonary edema
3. The Pipes
   1. AAA
   2. Aortic dissection
   3. DVT

The Protocol

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

• H - Heart (parasternal and four-chamber views)
• I - Inferior Vena Cava (for volume responsiveness)
• M - Morrison’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 PTX)

Heart

Technique: see Ultrasound: Cardiac

• Pericardial Effusion
  • Parasternal long
  • Change in size <30% between sys and dia = poor LV function
• RV collapse
  • In 4-chamber view, RV should be <60% of LV; if larger think RV failure
• Hyperdynamicity
  • Walls move >90% or touch at end of systole
    • May indicate hypovolemia or sepsis

IVC

Technique: see Ultrasound: IVC

• Measure 2cm from RA-IVC junction
• If IVC <1.5cm and collapses on inspiration then CVP is low
• If IVC >2.5cm and noncollapsing then CVP is high
  • Suggests fluid unresponsive; pt requires inotropes

Morison's

Technique: see Ultrasound: FAST

• Assess for free fluid
  • Morison's pouch
  • Splenorenal
  • Bladder

Aorta

Technique: see Ultrasound: Aorta

• If >5cm assume ruptured AAA until proven otherwise

Pulmonary

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 edema
• Assess for pneumothorax
  • Scan longitudinally in anterior 2nd-3rd IC space, mid-clavicular line
  • Look for lack of sliding or "beach sign"

See Also

• Ultrasound (Main)
• Shock

References

• Weingart - http://emcrit.org/ultrasound/The%20RUSH%20Examfinal.htm