This study demonstrates what many of us have probably suspected – the absence of cardiac activity on ultrasound portends a grave diagnosis; but this study really is so much more.
Utilizing 20 sites across the US and Canada from May 2011-Nov 2014 looked at all nontraumatic in-ED and out of hospital cardiac arrests that arrived to the ED in either PEA or asystole, and whether or not POCUS demonstrated a potential role in resuscitation.
953 patients, 793 used for final analysis (106 not included due to resuscitation under 5 minutes, 8 patients DNR, 1 uninterpretable sono, 3 with incomplete timing data, 42 for no ACLS meds given) – had a cardiac sono at the “beginning and end of ACLS.” The primary outcome was percentage of patients that survived to hospital admission, with secondary outcomes of survival to discharge and ROSC. Unfortunately, neurologic intact survival was not evaluated. The treating EP’s were credentialed in POCUS at their local institutions and unblinded. Digital clips were reviewed by a single reviewer in a blinded fashion for agreement (which was deemed to be “substantial agreement”).
The data (numbers are percentage, such that “28.9” = the percentage of patients with cardiac activity on POCUS during the resuscitation who survived to admission):
Cutting to the chase, this study brings up a number of key points:
-PEA on the monitor may not necessarily be PEA, with a whopping 54% of patients having cardiac activity on POCUS
-asystole on the monitor may not be cardiac standstill, as 10% had cardiac activity on POCUS
– survival to admission with cardiac activity on POCUS is MUCH higher – 28.9% vs 7.2%, but….
– cardiac activity on POCUS for PEA/asystole portends only a 3.8% survival to discharge
-no cardiac activity = poor prognosis, 0.6% of patients survived (3 out of 530). With two of the three patients were Vfib at some point during EMS working on them.
-pericardial effusion was seen in 34 patients (4.3% of those in the final analysis). 15.3% of patients whom had a pericardiocentesis performed survived to discharge.
– only 15 patients received lytics for suspected PE, with only one (6.7%) surviving to discharge. (which was almost the MORTALITY rate of PEAPETT)
Whew. This is a lot to digest. Let’s just say that ultrasound helps you tease out a spectrum of disease and further characterizes what you are dealing with. I’m looking at POCUS in codes as a risk stratification tool. Is there a prolonged time without cardiac activity without a potentially reversible causes? Might want to consider calling it earlier since survival to discharge is abysmally low. And sheesh… 1 out of 25 cardiac arrests had a pericardial effusion??? Wow. Time to brush up on those pericardiocentesis skills.
Caveats- this was done by EP’s credentialed for POCUS, so they’re likely more talented than the rest of us. Dont let that scare you though, rather, this. Perhaps seeing cardiac movement on ultrasound lends a “bridge to hope” and the team puts in a more-heroic-than-usual effort.
And of course, this also leads to more questions- of those 28.9% with cardiac activity that survive to admission, what if they are brought straight to the cath lab? Or started on ECMO? Would this potentially alter survival rates and neurologically intact survival in meaningful ways? Time shall tell. Until then, cut that KT window, pick up the probe, and have your TPA & long pericardiocentesis needle ready.