Ultrasound in Cardiac Arrest

Overview
When you are preparing the room for a cardiac arrest to arrive, don’t forget to bring the ultrasound machine (and if you can, bring a friend to help out). EMRA*Cast host Dustin Slagle, MD, speaks with ultrasound guru Michael Gottlieb, MD, RDMS, about the ways ultrasound can help your resuscitation of a cardiac arrest patient.

TAKE-HOME POINTS

Think of the ultrasound exam for cardiac arrest as two big chunks, with the first being the cardiac assessment itself.

In either the parasternal long axis or subxiphoid view, start your exam (parasternal long axis may be slightly preferred if the situation allows).¹ 

Some of the common findings for pulmonary embolism will not be present during a cardiac arrest (Mcconnell's sign, 60/60 sign, and perhaps D-sign as well) and so the evaluation will include comparison for right to left ventricle ratio, an assessment of right ventricle free wall thickness, and looking for a clot in transit. Clots in the heart can arise in the natural course of a cardiac arrest and so early assessment is necessary.²

The evaluation will also include an assessment for a large pericardial effusion, and if found, an ultrasound cardiac pericardiocentesis can be considered. 

Lastly, a visual check for fibrillatory ventricular activity can possibly detect shockable states that aren’t apparent on the monitor. 

After this cardiac assessment is complete, the second part is to use the ultrasound to check for other diagnoses based on history and arrest characteristics and can also be used for pulse checks and to help complete procedures. 

Ultrasound protocols developed for shock assessment (like the RUSH exam) can be co-opted for cardiac arrest as the differential for these two states overlaps significantly.³

Pro-Tips

1. Don’t delay return to compressions–clip your best view and review the images once compressions have resumed
2. Ultrasound pulse checks have been shown to be faster in a RCT4
3. Bring the ultrasound into all cardiac arrests to normalize its need and benefit to being in the room
4. Quick confirmation of correct I/O placement can prevent ineffective resuscitation 
5. The ultrasound can confirm ETT placement in a situation where ETCO2 may not be accurate

References

1. 1. Gaspari RJ, Gleeson T, Alerhand S, et al. A Multicenter, Prospective Study Comparing Subxiphoid and Parasternal Views During Brief Echocardiography: Effect on Image Quality, Acquisition Time, and Visualized Anatomy. J Emerg Med. 2022 May;62(5):648-656.  
   2. Lau V, Blaszak M, Lam J, German M, Myslik F. Point-of-Care Resuscitative Echocardiography Diagnosis of Intracardiac Thrombus during cardiac arrest (PREDICT Study): A retrospective, observational cohort study. Resusc Plus. 2022;10:100218. 
   3. Weingart SD, Duque D, Nelson B. Rapid Ultrasound for Shock and Hypotension (RUSH-HIMAPP). EMed Home. 2009.
   4. Badra K, Coutin A, Simard R, Pinto R, Lee JS, Chenkin J. The POCUS pulse check: A randomized controlled crossover study comparing pulse detection by palpation versus by point-of-care ultrasound. Resuscitation. 2019;139:17-23.