Scientists studying resuscitation say humans aware during minutes after death; call for more research

A research article almost 2 years old is seeing a revival of its own as it describes patients' awareness described by watching doctors and nurses working while they were in cardiac arrest. The team of researchers, from New York's Stony Brook University of Medicine, are working to improve treatment of cardiac arrests and prevent brain injuries during resuscitation, but they're also calling for large-scale investigation of out of body experiences (OBEs) and the explanation of awareness that occurs when the brain is supposedly non-functional.


'near-death experience' (NDE) and 'out of body experiences' (OBEs)

According to patient interview: During cardiac arrest, conscious awareness appeared to have lasted a number of minutes into the period when the brain ordinarily stops functioning and cortical activity ceases. As this recollection also corresponded with real and verifiable events, it appeared incompatible with a hallucination or illusion. Two individuals described 'seeing' and 'hearing' actual events related to the period of Cardiac Arrest compatible with OBEs.

Current research indicates that, regardless of cultural background, adults and young children (<3 years) have described comparable experiences in association with death. These include: feelings of immense peace and love; a sensation of going through a tunnel; seeing a bright warm welcoming light that draws the person toward it; meeting a 'being of light'; a feeling of entering a beautiful 'heavenly' domain; and encountering deceased relatives who are often perceived as greeting and welcoming the individual. A review of the person's life from early childhood onward is another commonly reported experience, as is a sense of separating from the body and looking down from above, while observing events during their resuscitation. This has often been referred to using the ill-defined term of out of body experiences (OBEs).

S. Parnia. Understanding the cognitive experience of death and the near-death experience. QJM: An International Journal of Medicine, Volume 110, Issue 2, 1 February 2017, Pages 67–69,


"post-resuscitation management strategies"

Of the approximately 350,000 out-of-hospital, and 750,000 after in-hospital cardiac arrest (CA) events in the US annually approximately 5-9% and 20% respectively may achieve return of spontaneous circulation (ROSC) after attempted cardiopulmonary resuscitation (CPR). Up to 2/3 of these initial survivors may go on die in the subsequent 24-72 hours after ROSC due to a combination of (1) on-going cerebral injury, (2) myocardial dysfunction and (3) massive systemic inflammatory response. In order to successfully manage patients more effectively, monitoring methods are needed to aid clinicians in the detection and quantification of intra-cardiac arrest and post-resuscitation pathophysiological cerebral injury processes in the intensive care unit.

Over the last few years many modalities have been used for cerebral monitoring during and after CA, these include quantitative pupillometry, transcranial doppler sonography, optic nerve sheath diameter measurements, microdialysis, tissue oxygenation monitoring, intra-cranial pressure monitoring, and electroencephalography. Current studies indicate that these modalities may be used for the purpose of neurological monitoring during cardiac arrest resuscitation as well as in the post-resuscitation period. Multiple overlapping processes, including alterations in cerebral blood flow (CBF), raised intracerebralpressure, disorders of metabolism, imbalanced oxygen delivery and reperfusion injury contribute to cell death during the post-resuscitation period has led to the birth of post-resuscitation management strategies in the 21st century.

Sinha N, Parnia, S. Monitoring the Brain After Cardiac Arrest: a New Era. Curr Neurol Neurosci Rep. 2017 Aug;17(8):62. doi: 10.1007/s11910-017-0770-x.

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"return of spontaneous circulation (ROSC)"

While poorly correlated, Cerebral Oxygen Saturation (rSO2) and End Tital CO2 (ETCO2) have similar diagnostic characteristics. ETCO2 is more sensitive and rSO2 is more specific at predicting ROSC in Out-of-Hospital Cardiac Arrest (OHCA).

Singer AJ, Nguyen RT, Ravishankar ST, Schoenfeld ER, Thode HC Jr, Henry MC, Parnia S. Cerebral oximetry versus end tidal CO2 in predicting ROSC after cardiac arrest. Am J Emerg Med. 2018 Mar;36(3):403-407. doi: 10.1016/j.ajem.2017.08.046. Epub 2017 Aug 25.