Ultrasound Detection of Pulseless Rhythm with Echocardiographic Motion (PREM) in Prehospital Cardiac Arrest: A Case-Series.

Objectives: This case series highlights the utility of Point of Care Ultrasound (POCUS) during cardiac arrest pulse checks, and how this tool can be used to identify Pulseless Rhythm with Echocardiographic Motion (PREM), also known as pseudo-pulseless electrical activity (PEA), and the potential changes in prehospital resuscitation management based on that finding.

Methods: We've documented four cases of PREM identification in the prehospital field to draw attention to this phenomenon and ideally serve as a blueprint for other agencies to adopt PREM-specific protocols.

Results: This case series demonstrates how cardiac visualization alters patient management in the setting of cardiac arrest. Each of the cases presented is unique in presentation and treatment. The use of POCUS has opened a door to the possibility of adopting prehospital guidelines for the management of PREM in prehospital cardiac arrest and subsequently more tailored treatment of patients.

Conclusions: Use of portable ultrasound in prehospital cardiac arrest highlights a large gap in our understanding and treatment of PREM. While these patients all ultimately died, their cases highlight the opportunity for more appropriate care, both prehospital and in-hospital. Because literature has posited that PEA is a more complex cardiac rhythm than previously thought, we are suggesting that pre-hospital cardiac arrest care guidelines reflect our current body of understanding. These cases emphasize the importance of emergency medical service (EMS) POCUS use and supports a transition to hands-free, or ultrasound-guided, pulse checks during cardiac arrest. More research is needed regarding the etiology of Pulseless Rhythm with Echocardiographic Standstill (PRES) versus PREM, what treatment guidelines would be best in cases of PREM, and how we can implement PREM recognition to health care personnel of all levels on a national scale.