Use the ultrasound in PEA arrest but know the pitfalls:

• If there is cardiac activity, patients may do better with Ultrasound (Resuscitation 2016 trial). 

• Physicians are not reliably able to diagnose cardiac standstill except in certain physician subgroups (Annals 2017). 
• The REASON Trial suggests that patients with organized cardiac activity on a continuous adrenergic drip do better as compared to patients given standard ACLS dosing of drugs. (Resuscitation 2016)
• Routine use of ultrasound in cardiac arrest pulse checks were associated with a longer pause for pulse checks - 23 seconds v. 13 seconds. 

References:

T’Veld, Ultrasound use during cardiopulmonary resuscitation is associated with delays in chest compressions, Resuscitation, 2017.

Hu et al, Variability in Interpretation of Cardiac Standstill among Physician Sonographers, Annals of Emergency Medicine, 2017.

Gaspari et al, Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. Resuscitation 2016.

Gaspari et al, A retrospective study of pulseless electrical activity, bedside ultrasound identifies interventions during resuscitation associated with improved survival to hospital admission. A REASON Study, Resuscitation 2017.