Ultrasound: In Shock and Hypotension
Rapid Ultrasound for Shock and Hypotension (RUSH) using the HI-MAP approach
H – Heart
Pericardial effusion can be seen with parasternal long view. LV assessment is also from the parasternal long view. A change in size less than 30% between systole and diastole indicates poor LV function. Alternatively, the LV is hyperdynamic if walls move more than 90% or touch at the end of systole, which can happen with hypovolemia or sepsis.
In four-chamber view, RV should be <60% of LV size – when RV is about the same size or larger than LV, think RV failure.
==I – IVC==
Start with the probe longitudinal and subxiphoid and slide 1-2 cm to the patient’s right. Look at IVC changes to inspiration. If the IVC is less than 1.5 cm and collapses on inspiration, the CVP is low and the patient probably needs fluid. A larger (>2.5cm) noncollapsing IVC suggests high CVP and the patient’s hypotension may require inotropes or reducing afterload.
- Note: IVC assessment in vented patients requires a tidal volume of 10 mL/kg during the exam. A change in [(inspiratory size – expiratory size) / expiratory size] > 18% predicts good response to IVF.
M – Morison's
the familiar Morison’s pouch and FAST views, covered in Ultrasound Basics. Tilting the probe chestward can show fluid at the lung/diaphragm interface.
A – Aorta
The aorta (also covered in ultrasound basics) can be seen in cross section sliding down from the subxiphoid to the umbilicus. If the aorta is larger than 5 cm below the heart or in the suprarenal, infrarenal or bifurcation views, you must assume ruptured AAA.
P – Pneumothorax
PTX can be seen by ultrasound. Using a high-frequency probe, scan longitudinally in both anterior 3rd intercostal spaces
using M-mode. Finding an ocean/beach or seashore sign reassures that there is no pneumothorax under the probe (immobile soft tissue and
muscle on the top of the M-mode image looks like an ocean, and the sliding lung tissue looks on the bottom looks like a beach). If the
whole image looks like the ocean pattern (stratosphere sign), a pneumothorax is likely.
Adapted from Scott Weingart and others -- http://emcrit.org/ultrasound/The%20RUSH%20Examfinal.htm