Link to AHA 2022 AWARE II abstract
Now to the presentation.
The background looks at the physiological factors around death and resuscitation, and has a slide on the pig study. It then looks at the different types of experience that are recalled, and also the psychological impact of these experiences. The historically low percentage of visual recollections is highlighted and he uses AWARE I as a source of evidence for this. He then moves on to the study itself.
Firstly he states 3 specific hypotheses related to Near Death Experiences:
- Consciousness and awareness - with explicit and implicit learning - and cognitive experiences occur during cardiac arrest
- Cognitive experiences may be related to the quality of brain resuscitation.
- Experiences during states of unconsciousness may impact longer term psychological outcomes in survivors
In subsequent slides he details the design of the study, and there is a new twist to this. Due to the lack of survivors from CA, a sad but inevitable problem that has plagued all his studies, he has decided to include retrospective data from reports of consciousness during CA that did not occur within the prospective AWARE II study. This was to provide qualitative information on experiences. As a researcher myself, I find the inclusion of retrospective data in a prospective study a little troublesome. I get why he might do this, but it makes the research potentially messy. However, thankfully that does not happen when it comes to the presentation of the prospective results.
After this the other techniques are discussed - brain oxymetry, EEG, headphones and a tablet generating audio and visual "clues".
During the study memories that were reported were measured against a 32 point NDE scale, and any visual or auditory reports were collected and cross referenced with computer files listing the clues that were generated at the various timepoints.
As the abstract states 567 patients were "recruited", but only 53 survived to discharge and of these only 28 were interviewed.
This is where I actually want to stop writing this post. It is incredibly disappointing to have such low numbers. In truth after more than 5 years they only obtained a sample of 28 subjects to glean information from. This is less than the number for AWARE I. I am not criticizing Parnia or his team - what they are aiming to do is very hard, and the fact that so few patients survive is the main reason why in my view, and I suspect the view of most who frequent this blog, the study "failed". Given that from previous studies we know that only 2-3% of patients who experience clinical death and are resuscitated report NDEs with visual recollections, I have always said that you would need to have many hundreds, if not thousands, of interviews to stand a chance of getting a hit. The reasons for this are not just related to low percentages having visual recollections, but also to the chances of someone actually seeing and remembering the projected images if they were lucky enough to have a visual OBE. Anyway, I have flogged that horse to death many times here so back to the results.
In terms of patient characteristics, due to the low numbers of patients who were interviewed vs not interviewed, which mainly reflects survival vs non-survival, most differences do not reach statistical significance, except sex with a higher proportion of men being interviewed than women than the proportion reflected in the total study population, and age, with those being interviewed being younger. The first point is interesting since I think that historically women were more likely to report NDEs than men. Oxymetry data shows a trend of higher levels of oxygen in patients who survived. This has been observed before.
In terms of participating sites, the greatest proportion of patients came from the UK.
Now we get to some interesting tidbits...I'd love to post the graphics, but that would be disrespecting the kind chap who provided me with the slides.
There is a flow chart showing % of patients who had a tablet , oximetry and EEG installed, with the key data being for those who survived to interview (28):
- 22 had tablets with files recording what was displayed
- 24 had oximetry with 11 having meaningful files
- Only 6 had EEG installed and if I am reading the flow chart correctly, only 2 of those interviewed had interpretable EEG files.
How many reported awareness?
- 11 of the 28 patients had memories or perceptions.
- 6 reported transcendent experiences of death (he seems to have dropped RED in this manuscript and gone back to TED )
- 2 reported CIPRIC
- 2 had memories post CPR
- 3 had dream or dream-like experiences
The 6/28 is where Parnia get's his 20% having NDEs (21% to be precise). Given the small sample size this is well within the bounds of error of previously reported numbers of 10%. Now for the core bits of data...the OBEs.
- 2 of 28 had auditory OBEs
- 1 of 28 had a visual OBE
- None of 28 were able to identify the correct image including the patient who had a visual recollection - big miss for us on this blog
- 1 subject was able to identify the correct fruit from the auditory stimuli. This is the hit that was first mentioned back in 2019. It's hard to know what to make about this without ECG and/or EEG data correlating with the time of the audio file. It could be a bona fide hit. Either way, this possibly fully verifies his first hypothesis provided the patient was proven to be in CA.
In terms of EEG:
- Absence of measurable cortical brain activity (47% of images)
- Normal/near-normal delta seen in 22% of recordings up to 60 minutes
- Theta activity was seen in 12% of recording up to 60 minutes
- Alpha activity was seen in 6% of recordings, up to 35 mins
However, these are not specific to patients who were interviewed, so all the talk about recollections of consciousness possibly being related to brain activity are 100% pure speculation - UNLESS the 2 EEG files he has from the interviews specifically cross reference recollections with EEG spikes from the 6 patients who had NDEs. However we aren't told this. It is possible that this data was verbally discussed during the presentation or more likely will be presented in the final publication. It is an important piece of data, but given that there are only 2 EEG files for the 28 who survived, even if there is some correlation with one or two of the six, the numbers are way too low to draw definitive conclusions and so I am of the view that Parnia's reference to these recollections of Awareness being related to these is at best speculative.
The last section of the presentation refers to the retrospective study and repeats much of what has been said in the consensus statement and distinguishes REDs (yes, he uses RED here rather than TED) from other CPR related experiences such as CIPRIC.
In summary, in the absence of scientifically verified OBE or EEG data corelating specifically with strong NDEs, or an OBE, we have got nowhere. This is entirely attributable to the low numbers recruited in the study. From the PowerPoint presentation that I have, no hypothesis, either his, or ours, relating to the nature or origin of conscious awareness during CA has been validated or falsified. Given how much hope I once had for this study, I am of course very disappointed, but such is life.
I anticipate lots of questions and a lively discussion!!
Lastly I would like to thank the lab for providing the slides for me to look at and pay my respects to the Parnia lab team, all the research sites, and the patients who took part in this study. It is no one's fault that this study does not satisfy our desire for a "hit", it was an epic effort and the nature of the population always made this outcome more likely than not. Also, there is another study that we still have to hear about...another day. I live in hope!!