By Ben Dowdy
A cardiac arrest patient who presents with PEA as their initial rhythm is a challenge to the resuscitation team. The differential diagnosis is wide, and the ACLS algorithm for PEA and asystole doesn’t offer much in the way of guidance. Maybe that’s why patients who present with PEA seem to have worse outcomes than those with shockable rhythms [1,2].
Despite that evidence, successful resuscitation is possible. These patients exemplify the idea that ACLS is a holding pattern, providing organ support while the resuscitation team identifies and fixes the underlying cause. Here are 5 tips to give you a better shot at bringing back a patient with pulseless electrical activity (PEA):
1. Pay attention to the ECG rhythm
The H’s and T’s mnemonic is a somewhat comprehensive listing of possible causes of PEA, but it doesn’t provide much in the way of guidance on which possible causes you should look into first. The ECG rhythm, or more specifically whether the QRS is narrow or wide, can give you some insight into likely reasons this patient arrested. Littmann, Bustin, and Haley have a great article that explains this approach in detail. Here’s a summary [3]:
- Narrow QRS complexes typically indicate an inflow or outflow problem with the right side of the heart. Problems like hypovolemia, tension pneumothorax, or hyperinflation of the lungs decrease inflow of blood into the right atrium and ventricle, reducing stroke volume and cardiac output. Cardiac tamponade or a pulmonary embolism obstructs the right ventricle’s ability to pump blood to the pulmonary circulation and to the left atrium and ventricle.
- Wide QRS complexes typically indicate a metabolic problem (such as hyperkalemia or sodium-channel blockade from a toxic overdose), or left ventricular failure (either acute or chronic).
2. Assess the patient’s medical history
Paying attention to the characteristics of the ECG rhythm can narrow the field of possibilities some, but assessing the patient’s medical history and performing a quick physical exam are still crucial for identifying the cause of PEA. Are there risk factors for PE or hyperkalemia? Any scene indicators that an overdose might have occurred? Jugular venous distension or minimal chest rise that might suggest cardiac tamponade or tension pneumothorax?
Veinity Fair: Evaluating jugular venous distension]
3. Get a 12-lead ECG
If there aren’t any big red flags pointing you towards any of the possible H and T causes, consider stopping CPR for enough time to acquire a 12-lead ECG. Before raising objections, hear me out; you can still place the precordial electrodes appropriately (or very closely) while chest compressions are ongoing, and acquiring a 12-lead ECG only takes about 10 seconds, so there’s no need to pause high-quality CPR for longer than the AHA currently recommends.
And in cases where the likely cause of arrest is elusive, the information from a 12-lead ECG can help immensely. If you’re not up to speed on the suspicious findings for coronary occlusions, hyperkalemia, or pulmonary embolism from a 12-lead ECG, get studying!
4. If it’s PEA from traumatic arrest, hold off on CPR
If your protocols allow field termination or not starting CPR, follow your protocol. If they don’t, what a wonderful topic to research and present to your medical director, especially if the number of providers on scene is limited.
The AHA recommends standard-practice CPR in cases of traumatic cardiac arrest, but offers no evidence that it works, and the survival rate from traumatic cardiac arrest is dismal [4]. The likely causes of PEA in traumatic arrest are hypovolemia, tension pneumothorax, and cardiac tamponade; if the hands can be redirected from chest compressions to a procedure that corrects an underlying cause, like airway management, IV/IO access and a fluid bolus, decompressing a pneumothorax, pericardiocentesis, or binding the pelvis, prioritize that instead of mashing the chest.
Maybe a more polite way to say this is “do not prioritize chest compressions over life-saving interventions.” If none of those interventions work and you decide to transport the patient, or if enough providers are on scene, CPR still may have a role in managing traumatic cardiac arrest, but it’s definitely debatable.
5. Investigate point of care ultrasound
Point of care ultrasonography has a lot of potential uses in the prehospital setting, but use during cardiac arrest is arguably the most useful. Looking at the inferior vena cava can help identify patients who need fluid; looking at the lungs can help identify patients with a tension pneumothorax; looking at the left ventricle during a rhythm check can assess left ventricular function. Ultrasound has a lot to offer the resuscitation team (and the patient) during a PEA arrest.
Cardiac arrest that presents with PEA can be a tough nut to crack, and many times, a bolus of epinephrine every 3-5 minutes just won’t cut it, but these strategies for PEA management can help you dissect your way down to the underlying cause. And at the end of the code, that’s what offers your patient their best chance for survival!
References
1. Nadkarni VM, Larkin GI, Peberdy MA, et al. “First documented rhythm and clinical outcome from in-hospital cardiac arrest among children and adults.” JAMA 2006;295:50-57.
2. Hess EP, Campbell RL, White RD. “Epidemiology, trends, and outcome of out-of-hospital cardiac arrest of non-cardiac origin.” Resuscitation 2007 Feb;72(2):200-6.
3. Littmann L, Bustin DJ, Haley MW. “A simplified and structured teaching tool for the evaluation and management of pulseless electrical activity.” Med Princ Pract 2014;23:1-6. http://www.karger.com/Article/FullText/354195
4. Vanden Hoek TL, Morrison LJ, Shuster M, et al. “Part 12: Cardiac Arrest is Special Situations: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.” Circulation 2010;122:S829-S861
About the Author
Ben Dowdy B.S., NR-P currently works in northern Idaho for a rural/frontier EMS system. His past experiences include work as a field provider, tactical paramedic, paramedic for the National Parks Service, and EMS educator. He is a lead instructor for Wilderness Medical Associates, for whom he has taught medical courses for providers of all levels throughout the US as well as abroad.
This article was originally posted June 29, 2015. It has been updated.