ULTRASOUND AND PROGNOSIS IN CARDIAC ARREST

Point of care- and portable ultrasound is a silent revolution in emergency care. An article in Academic Emergency Medicine helps me understand what to expect when applying an echo probe in cardiac arrest, and what that means for the patient’s prognosis.

Background
With ultrasound we can reliably identify some potentially reversible causes of cardiac arrest like PE, tamponade and pneumothorax. Ultrasound has also been used in attempts to predict prognosis. The absence of ventricular activity has been promoted as a way to confirm poor prognosis and help the decision to terminate resuscitation. The presence of cardiac motility, on the other hand, could be a cue for prolonged resuscitation or a more aggressive approach.

The study
Ultrasound as predictor of futility and mortality in cardiac arrest has been explored in several studies and case series.  All of them confirms poor prognosis with no contractility on echo. At least one of them exclude functional recovery at all. All of those studies suffer from being very small.

This review is an attempt at a meta-analysis of 8 of those studies.  Out of those 8 studies, the authors extracted 568 cardiac arrest patients where transthoracic echo was performed during cardiopulmonary resuscitation. The clinical question to be answered was ´does detection of cardiac contractility on bedside echo predict ROSC?

Results
The big picture is presented in the table. Overall chance of ROSC in this population is 19%.

According to these numbers:
- approximately 34% (n=190) of cardiac arrests will display cardiac contractility during ongoing CPR.
-Of these 52% (n=98) will achieve ROSC

On the other hand:
-66% (n=378) displayed no cardiac contractility on US.
-In only 2,4% of these patients, ROSC was achieved.

Take-home message
The likelihood of achieving ROSC in a patient with no cardiac activity on echo is minimal but not zero.

Study lives here:
Acad Emerg Med. 2012 Oct;19(10):1119-26. doi: 10.1111/j.1553-2712.2012.01456.x. Epub 2012 Oct 5.
Bedside focused echocardiography as predictor of survival in cardiac arrest patients: a systematic review.
Blyth L, Atkinson P, Gadd K, Lang E.

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2 Responses to ULTRASOUND AND PROGNOSIS IN CARDIAC ARREST

  1. Thanks for mentioning this article, I think it’s highly important to stay up-to-date with the literature in this field since it’s a “point and shoot” procedure of just putting the probe on and even a kid can tell if the heart is beating or not. But as you say – even in standstill there is a slight chance of ROSC and we definitely don’t want to miss these without reversing all possible causes.

    Then there is the more difficult scenario of seeing contractions but deciding to stop resuscitation anyway for example after a very long prehospital code/transport where there in many cases is assumed brain death despite cardiac function (just witnessed one such a few days ago). That brings us to the question how do we emergency physicians evaluate brain death with full certainty in the ED, something I haven’t been trained to do…

    • Thomas D says:

      Thanks for your comment, and we agree, and just as the article says, cardiac movement on ultrasound is not to be used as the only criterium for continuing/stopping resuscitation. You still need to apply your clinical skills and get an overview of the situation, but this quick cardiac ultrasound can be a great help in making the decision. And I suspect the ultrasound will often confirm your gut feeling and help you follow that.

      You can’t really evaluate brain death in a meaningful way in the emergency situation. I’ve seen enough long codes get ROSC and later wake up again with normal brain function when I was sure their brain must’ve been fried, so I’m keeping focus on the patient’s ABC and leave the brain function evaluation for someone else at a later stage.

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