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.
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.
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?
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.
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.