CPR-related cognitive activity, consciousness, awareness and recall, and its management: A scoping review

Abstract

Background: There are increasing numbers of reports of cognitive activity, consciousness, awareness and recall related to cardiopulmonary resuscitation (CPR) and interventions such as the use of sedative and analgesic drugs during CPR.

Objectives: This scoping review aims to describe the available evidence concerning CPR-related cognitive activity, consciousness, awareness and recall and interventions such as the use of sedative and analgesic drugs during CPR.

Methods: A literature search was conducted of Medline, Embase and CINAHL from inception to 21 October 2021. We included case studies, observational studies, review studies and grey literature.

Results: We identified 8 observational studies including 40,317 patients and 464 rescuers, and 26 case reports including 33 patients. The reported prevalence of CPR-induced consciousness was between 0.23% to 0.9% of resuscitation attempts, with 48-59% of experienced professional rescuers surveyed estimated to have observed CPR-induced consciousness. CPR-induced consciousness is associated with professional rescuer CPR, witnessed arrest, a shockable rhythm, increased return of spontaneous circulation (ROSC), and survival to hospital discharge when compared to patients without CPR-induced consciousness. Few studies of sedation for CPR-induced consciousness were identified. Although local protocols for treating CPR-induced consciousness exist, there is no widely accepted guidance.

Conclusions: CPR-related cognitive activity, consciousness, awareness and recall is uncommon but increasingly reported by professional rescuers. The data available was heterogeneous in nature and not suitable for progression to a systematic review process. Although local treatment protocols exist for management of CPR-induced consciousness, there are no widely accepted treatment guidelines. More studies are required to investigate the management of CPR-induced consciousness.

Keywords: ALS, Advanced life support; Awareness; CPR, Cardiorespiratory resuscitation; Cardiac arrest; Cardiopulmonary resuscitation; Consciousness; ED, Emergency Department; EMS, Emergency medical service; GCS, Glasgow coma scale; ICU, Intensive care unit; IHCA, In-hospital cardiac arrest; ILCOR, International Liaison Committee on Resuscitation; Near death experience; OHCA, Out-of-hospital cardiac arrest; OR, Odds Ratio; PTSD, Post-traumatic stress disorder; Post-traumatic stress disorder; ROSC, Return of spontaneous circulation; VF, Ventricular fibrillation; VT, Ventricular tachycardia; pVT, pulseless ventricular tachycardia.

Fig. 1

PRISMA flow diagram.