LINCOLN, Neb. — EMS leaders and clinicians warn that patients receiving high-quality CPR, especially from mechanical CPR devices, can achieve some level of consciousness or alertness without a spontaneous heartbeat. That awareness may put the patient, as well as their health care providers, at risk of psychological or physiological consequences.

A letter from Donald Rice, with the Nebraska Office of EMS, in the journal Resuscitation, "CPR induced consciousness: It's time for sedation protocols for this growing population", describes a 55-year-old Nebraska man who experienced out-of-hospital cardiac arrest [1].

A LUCAS 2 Chest Compression System was used on the patient in the field and in the emergency department. The patient achieved ROSC before V-fib reoccurred in the emergency department.

"The patient remained awake, alert, able to speak and engaged in purposeful movements during chest compressions," Rice wrote. "The ED staff was able to communicate to the patient, including warning him when they were going to defibrillate."

The man was sedated with ketamine because of his continued consciousness. After another 23 minutes of resuscitation, he again attained sustained ROSC.

The patient was successfully treated and before discharge he recalled events in the emergency department, while receiving mechanical compressions, up to the point of the ketamine administration.

"An unintended consequence of improving resuscitation techniques may be that we are subjecting 'aware' patients to psychological trauma and the physical pain of CPR with increasing frequency," Rice wrote. "Of additional concern is the physiological response to these factors and their impact on critically ill patients in the pre-, peri- and post-arrest phases."

A multi-year, multi-center, prospective study of the frequency of awareness during resuscitation by interviewing cardiac arrest survivors after discharge found 55/140 of the patients had perceptions of awareness of being alive and even memories that originated during the resuscitation.

Nebraska EMS protocols direct paramedics to administer a ketamine bolus if a patient has any signs of consciousness — spontaneous eye opening, purposeful movement or verbal response to include moaning. Those medics should also consider a midazolam bolus and repeat ketamine boluses or infusion for continued patient sedation.

The letter concludes with a call for more research, education and training in the management of cardiac arrest patients who achieve consciousness because of the high-quality CPR they are receiving.

Reference

1. Rice DT, et al. CPR induced consciousness: It’s time for sedation protocols for this growing population. Resuscitation (2016), http://dx.doi.org/10.1016/j.resuscitation.2016.02.013