Ultrasound in resuscitation

Point-of-care ultrasound can rapidly narrow the differential in undifferentiated shock and identify immediately reversible causes of arrest. In resuscitation, its highest value is as a bedside physiologic data point for cardiac function, tamponade, right-heart strain, pneumothorax, and volume tolerance.

Ultrasound for Shock and Arrest

• Undifferentiated shock framing: POCUS is most useful when shock is clinically unclear, helping separate cardiogenic, obstructive, and hemorrhagic patterns quickly enough to change the next test, consultant, and first moves.
• Gross cardiac function check: A rapid look at overall myocardial squeeze is an essential bedside skill in crashing patients, and often gives a faster hemodynamic read than waiting for formal imaging.
• Femoral flow assessment: Femoral artery flow on ultrasound can be more informative than pulse palpation during a code, especially when pulse checks are equivocal. We get into the bedside technique in the episode.
• Myocardial motion in arrest: True myocardial motion matters more than blood swirling in the chambers and is a stronger survival prognostic sign than many clinicians realize.
• Standstill prognostic caution: Cardiac standstill carries a grim prognosis, but it is not absolute; rare patients still survive, so ultrasound findings have to be interpreted in the full clinical context.
• Shockable rhythm limitation: In clearly shockable arrests, ultrasound often adds less because the immediate priority is defibrillation, stabilization, and rapid cath-lab thinking rather than image-driven diagnosis.

Focused Resuscitation Ultrasound Exam

• Core multiorgan survey: A high-yield resuscitation scan pairs the heart with IVC, lungs, and FAST views to look for tamponade, RV enlargement, free fluid, pleural pathology, and fluid tolerance clues.
• Right ventricle clues: An enlarged right ventricle in the right context raises concern for obstructive shock from pulmonary embolism, especially when paired with the rest of the resuscitation exam.
• IVC interpretation limits: IVC size and collapsibility can support fluid decisions, but they are not standalone truth and should never override the broader hemodynamic picture.
• Lung ultrasound yield: Lung views can quickly identify pneumothorax, pleural effusion, and B-lines, giving actionable information during shock without moving an unstable patient.
• Optional DVT extension: A focused DVT study can complement a PE workup when the cardiac views suggest right-heart strain. We walk through when that add-on scan is worth the time in the chapter.
• Outcome reality check: Ultrasound improves diagnostic certainty and resuscitation direction more reliably than mortality, so its value is in sharpening bedside decisions rather than acting as a magic test.

References:

1. Kim DJ, et al. POCUS literature primer: key papers on POCUS in cardiac arrest and shock. CJEM. 2024 Jan;26(1):15-22. Epub 2023 Nov 23. PMID: 37996693.
2. 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.
3. Shokoohi H, et al. Bedside Ultrasound Reduces Diagnostic Uncertainty and Guides Resuscitation in Patients With Undifferentiated Hypotension. Crit Care Med. 2015 Dec;43(12):2562-9. PMID: 26575653.
4. Atkinson PR, et al. Does Point-of-Care Ultrasonography Improve Clinical Outcomes in Emergency Department Patients With Undifferentiated Hypotension? An International Randomized Controlled Trial From the SHoC-ED Investigators. Ann Emerg Med. 2018 Oct;72(4):478-489. PMID: 29866583.
5. Díaz-Gómez JL, Mayo PH, Koenig SJ. Point-of-Care Ultrasonography. N Engl J Med. 2021 Oct 21;385(17):1593-1602. PMID: 34670045.