Near Death Experiences in Survivors of Cardiac Arrest

© G.M. Woerlee

 

Pim van Lommel is a Dutch cardiologist who performed one of the best and largest studies of near death experiences in survivors of cardiac arrest, as well as the consequences of such experiences. The results of this study were published in the international medical journal "The Lancet" during 2001 (see Near-death experience in survivors of cardiac arrest). This was a study reporting the results of standardized interviews of 344 patients who survived cardiac arrest. The group of Pim van Lommel found that about 18% of people reported undergoing near death experiences during the period of cardiac arrest and cardiopulmonary resuscitation. Subsequently this group studied the psychological effects of these near death experiences upon these survivors for a period of 8 years after the first interview. This was an exceedingly well executed study. It required unbelievable tenacity and effort over many years to complete this study. Yet one aspect of the discussion of the experimental results of this wonderful study in the in the original Lancet article was truly remarkable (see page 2044 of Lommel 2001).

With lack of evidence for any other theories for NDE [near death experiences], the thus far assumed, but never proven, concept that consciousness and memories are localised in the brain should be discussed. How could a clear consciousness outside one's body be experienced at the moment that the brain no longer functions during a period of clinical death with flat EEG? Also, in cardiac arrest the EEG usually becomes flat in most cases within about 10s from onset of syncope.

Astounding! Pim van Lommel and his colleagues apparently did not understand how it was possible for these people to have complex conscious experiences, such as near death experiences, during cardiopulmonary resuscitation for cardiac arrest. These authors seemed to have forgotten, or worse yet, totally misunderstood the very purpose of cardiac massage as applied during cardiopulmonary resuscitation. Pim van Lommel has further developed this unbelievable lack of understanding exhibited in the quote above in a book published at the end of 2007 in the Netherlands called "Eindeloos Bewustzijn" (English translation - "Eternal Consciousness"). He seriously claims in this book that human consciousness is immaterial and functions independently of the body, and that the brain is just the receiver of the signals generated by this consciousness, much as a television is the receiver of signals from a television station. Furthermore, he claims in this book that the otherwise very good study published in the Lancet in 2001 is proof of this claim!

This website examines this remarkable conclusion. Readers will notice that clickable links are distributed throughout the text of this website. These are links to the original medical articles which the interested reader can download, read, and decide for themselves whether what I say on this website is correct. My recent book called The Unholy Legacy of Abraham contains an even more detailed study of these claims, as well as of the biological nature of all aspects of near death experiences. You can download this book for free by clicking the "FREE BOOK" item on the menu above

 

What is a cardiac arrest?

Cardiac arrest is a collective name for the effects of an abnormal , non-functional heartbeat - heartbeat which has stopped, or which is so abnormal that the heart no longer functions as a pump. And the function of the heart is to pump blood, circulating blood around the organs and tissues of the body. The flow of blood into organs transports oxygen, nutrients, hormones, and many other substances into these tissues, while the flow of blood out of the organs removes waste carbon dioxide, waste products of metabolism, hormones, and other substances. All organs and tissues of the body fail and die when this flow of blood ceases, and of all the organs of the body, the eyes and the brain are most sensitive to the effects of failure of the normal flow of blood.

Sudden cessation of the flow of blood to the head as occurs during cardiac arrest causes failure of the eyes and the brain manifesting as blindness and paralysis of all muscles after 3-19 seconds, followed by loss of consciousness after 4-20 seconds (Rossen 1943). This period of consciousness remaining after the heart stops is why some cardiac arrest patients complain bitterly when doctors and nurses begin cardiac massage before they lose consciousness. And this is why some people may remain conscious for several seconds after being shot or stabbed in the heart. Increasing degrees of brain damage occur 3 to 5 minutes after cardiac arrest occurs, and severe brain damage is present after more than 10 minutes cardiac arrest.

 

Cardiopulmonary resuscitation - what is cardiac massage?

A person who develops a cardiac arrest will die unless cardiopulmonary resuscitation is commenced. Cardiopulmonary resuscitation is not a passive affair where physicians and nurses stand back, arms crossed, while calmly observing a person with a cardiac arrest gradually fade away, calmly waiting for that person to spontaneously revive without any activity on their part, except perhaps for interested observation on the part of the observing physicians and nurses. Instead, physicians and nurses in modern Western European hospitals have a very standard reaction pattern when confronted with a person with a manifest cardiac arrest. They sound an alarm summoning a special resuscitation team, while at the same time hurling themselves upon the dying person like a pack of wild dogs. They lie the person flat on their back, place a hard plank under the chest, perform artificial respiration, insert an intravenous line through which medicines necessary to treat the cause of the cardiac arrest can be administered, and perform external cardiac massage.

External cardiac massage consists of vigorous and forceful compression and release of the chest 60-120 times per minute. The heart is a bag made of muscle tissue in which there are four one-way valves. Compression of the chest forces blood out of the heart and the chest, and because of the one-way valves in the heart, this emerges out of the heart into the arteries conducting it into the various organs and tissues of the body. Releasing the chest causes the chest to rebound to its original form, creating a negative pressure within the chest and heart, sucking blood into the chest and the heart. This cycle is repeated 60-120 times per minute, generating a pumping action, circulating blood around the body when the heart no longer does this during cardiac arrest. Circulation of blood generated by cardiac massage provides a flow of blood to the brain and other vital organs, keeping these organs alive until a normal heart rhythm is restored, and the heart pumps blood normally again. Cardiac massage is always applied during cardiac arrest. Failure to do so means no blood is pumped around the body of the person with a cardiac arrest, and that person will die. This means that people undergoing cardiac massage for cardiac arrest do have a flow of blood flowing through their brains.

So how much pumping action does cardiac massage generate? In other words, how many liters per minutes does the heart pump as a result of cardiac massage, and how much blood pressure is generated by cardiac massage?

 

Cardiac output generated by cardiac massage

To begin with, external cardiac massage is not a 100% predictable procedure. Because people applying external cardiac massage differ in strength, body size, and the energy they employ during external cardiac massage, the pumping action they develop in any individual with a cardiac arrest differs. This means that external cardiac massage is sometimes very efficient, and sometimes very inefficient. This is revealed by a study of the distributions of cardiac output measurements made during external cardiac massage in several studies of cardiopulmonary resuscitation (raw data from Christenson 1990, Del Guercio 1965, Liu 2002, MacKenzie 1964, Oriol 1968).

 

 

 

Blood pressure generated by cardiac massage

Studies of the effects of external cardiac massage applied to people with cardiac arrest reveal that external cardiac massage not only generates a flow of blood through the body, but also generates mean arterial blood pressures greater than 40 mmHg in 15% of people undergoing cardiac massage (see graphic below constructed with the raw data from: Del Guercio 1965, MacKenzie 1964, McDonald 1982, Oriol 1968, Swenson 1988, Wei 2006).

 

 

Chance of consciousness during cardiac massage

Studies of the distributions of blood pressure and cardiac output during cardiac massage provide essential information about whether people may, or may not be conscious during cardiac massage. These data do not tell us whether people may be conscious, instead it is first necessary to know the lowest blood pressure and lowest cardiac output capable of sustaining consciousness The first step is to know the minimum blood flow through the brain required to sustain some form of consciousness. This can be answered with a relatively easy calculation.

• The adult human brain weighs about 1500 grams.
• Normal flow of blood to the adult brain is about 54 ml/100 grams brain tissue/minute, which means a normal flow of blood through the adult brain of 810 mls/minute.
• Minimum flow of blood needed to sustain consciousness is 15 ml/100 grams brain tissue/minute, a total minimum blood flow of about 225 mls/minute in the average 1500 gram adult brain.
• About 13% of the blood pumped by the heart goes to the brain, the rest sustains the rest of the body. So the heart must pump at least 1730 mls of blood with normal oxygen content per minute to sustain some sort of consciousness in an average adult body.
• This calculation corresponds quite well with actual measurements of the lowest cardiac outputs capable of sustaining consciousness in adult humans.

Studies of the efficiency of cardiac massage reveal that cardiac massage generates a flow of blood greater than 1730 mls/minute in 20-50% of persons undergoing cardiac massage (see graph of distribution of cardiac output during cardiac massage). In other words, the cardiac output generated by cardiac massage is sufficient to sustain consciousness in about 20-50% of people during cardiopulmonary resuscitation for cardiac arrest.

The same is also true for blood pressure. In general, consciousness is possible when the mean arterial blood pressure is equal to, or greater than 40 mmHg. A review of several studies of blood pressures measured during external cardiac massage applied during cardiac arrest reveals that around 17% of people have blood pressures capable of sustaining consciousness (the interested reader can click on the links to download and read the original medical articles - Paradis 1989, Swenson 1988, Gurewich 1961, Wei 2006).

These raw data from cardiac massage studies performed during cardiac arrest fully explain why up to 18% of the 344 patients interviewed by Pim van Lommel and his co-workers reported being partially conscious, or undergoing near death experiences during cardiopulmonary resuscitation. The same is true for all other studies of near death experiences in survivors of cardiac arrest.

 

Flatline EEG and cardiac arrest

Pim van Lommel was quite correct in the Lancet article of 2001 (Lommel 2001) when he said that the EEG became a flat line, or that the EEG is "flatlined" 3-20 seconds after the heart stops beating. He cited articles by Aminoff 1988, and Clute 1990 who made actual measurements of these times. A more recent similar article was published by Visser in 2001, and interested readers can (download and read the article written by Visser in 2001). However, Pim van Lommel was totally and astoundingly incorrect on two counts when he asked, "How could a clear consciousness outside one's body be experienced at the moment that the brain no longer functions during a period of clinical death with flat EEG?" (Lommel 2001). This is an astonishing statement from a man who was once a cardiologist who managed many, many hundreds of cardiopulmonary resuscitations during his career.

There is a flow of blood through the brains of people undergoing cardiac massage for cardiac arrest. When this flow of blood is sufficient to sustain some form of consciousness, then these people certainly have an EEG, and are most definitely not "flatlined"

At the time Van Lommel performed his study, as well as at the present time in the Netherlands, and in the whole world for that matter - NO ONE EVER attaches an EEG measuring device to the heads of people undergoing resuscitation for sudden cardiac arrest. I know this to be a fact, because as an anesthesiologist working in the Netherlands, I also assist in the resuscitation of many people with cardiac arrest. And during a long career in anesthesiology in three countries, I have never seen or heard of an EEG machine being attached to the head of people undergoing resuscitation for sudden cardiac arrest. There are very good reasons for not doing so. EEG apparatus is very sensitive to the electrical noise generated by the shaking of the body caused by cardiac massage. Moreover, EEG apparatus is not available in all parts of a hospital, and is delicate apparatus requiring careful attachment to the body to yield usable results. Furthermore, most doctors cannot even interpret the signals from an EEG apparatus. All these things make the EEG unusable in the hectic situation of nearly all cardiac arrest and resuscitation events.

All this means that all statements about these patients having had a "flat EEG", or "flatlined" at the time of undergoing cardiac massage for cardiac resuscitation are pure speculation and incorrect. However, there are EEG readings from the few people who have undergone cardiac massage for cardiac arrest, as well as from people with mechanical hearts.

 

Is a normal heartbeat needed for EEG activity?

A normal heartbeat is not needed for EEG activity. This is proven by the example of some heart transplantation patients. Some people require heart transplantation because their hearts function so badly that they are barely able to stay alive. Many of these people die while awaiting a suitable human transplant heart, so some technically advanced medical centers in the USA remove the diseased heart, and replace it with a pneumatically driven mechanical heart to keep these people alive as they await a suitable transplant heart. Such a mechanical heart not only keeps these people alive, but enables them to resume reasonably normal life (click on this link to read the scientific article by Dr. Copeland reviewing the use of artificial hearts). These people have no heartbeat. Instead their blood is circulated around their bodies by a machine. Yet they are conscious and alive, which means they have a normal EEG in spite of an absent normal heartbeat.

This actually means that people need no heartbeat in order to have a normal EEG, what is needed is blood being pumped around the body. Cardiac massage does just this. Cardiac massage pumps blood around the body. And indeed EEG activity does return after effective external cardiac massage is instituted (see article by Losasso 1992, and case 5 in the article by Elton 1961).

Accordingly, statements claiming that all people have a "flat EEG", or are "flatlined" while undergoing external cardiac massage applied as part of cardiopulmonary resuscitation are pure speculation, and likely to be incorrect.

Indeed, external cardiac massage is sometimes so effective that some people are actually evidently awake even though they have no heartbeat at the time - just cardiac massage pumping blood around their bodies (see articles by Bihari 2008, and Lewinter 1989). This is absolutely positive proof that some people can have a normal EEG during external cardiac massage.

 

The results of Pim van Lommel explained

All these things clearly demonstrate why about 18% of the successfully resuscitated patients interviewed by Pim van Lommel were able to undergo near death experiences while undergoing cardiac massage as part of their cardiopulmonary resuscitation.

Even so, why did no one notice that these persons were conscious while undergoing cardiac massage and cardiopulmonary resuscitation? The answer is that these people were conscious but unable to move, because even though the flow of blood supplying oxygen to their brains was sufficient to sustain consciousness, it was insufficient to enable normal movement. This sounds surprising, but a person undergoing moderate to severe brain oxygen starvation due to cardiac arrest, (or any other form of oxygen starvation), can be in a condition in which they are paralyzed and unable to move, yet conscious and able to hear all that is happening about them (see the effects of oxygen starvation here). This is the situation in which the patients reporting near death experiences after successful resuscitation from cardiac arrest found themselves during their during their near death experiences. And all these people were not flatlined, instead they had an EEG appropriate to their clinical situation. But no-one knows this, because no-one ever measures the EEG of patients undergoing resuscitation for sudden cardiac arrest.

All this explains how it is that unmoving, unresponsive, apparently dead people undergoing cardiopulmonary resuscitation for cardiac arrest can undergo conscious experiences such as near death experiences. And the fact that oxygen starvation inhibits formation of memories explains why only 18% of these people can undergo, or rather, remember such a conscious experience. The book "Mortal Minds" provides a more extensive discussion of how the functioning of the body in these situations can generate all the other phenomena associated with these near death experiences, such as the experience of light, the tunnel, the sensations of ineffability, life review, out of body experiences, etc (see chapter 17 in "Mortal Minds", and chapters 5 to 12 of The Unholy Legacy of Abraham).

 

Near death experiences in survivors of cardiac arrest

Oxygen starvation during cardiopulmonary resuscitation for cardiac arrest generates such a standard set of changes (read about the surprising effects of oxygen starvation here), that it is possible to describe a stereotype near death experience as reported by a cardiac arrest survivor:

The flow of blood to the body stops because the heartbeat is so abnormal that no blood is pumped by the heart, or the heart stops beating, and the brain is subjected to total oxygen starvation. The small reserve of oxygen within the blood and the cells of the brain is soon exhausted, causing rapidly progressive oxygen starvation. Oxygen starvation of the brain first causes failure of prefrontal cortex function, causing the patient to feels serene and indifferent as he/she gradually "fades away". Subsequently, oxygen starvation of the brain causes failure of those parts of the brain called the supplementary motor cortex, the frontal eye fields, Broca's speech cortex, and the primary motor cortex. Failure of these parts of the brain causes the eyes to stare fixedly straight ahead, the person is paralyzed and unable to move or speak, even when they try to do these things. At this time the retina also fails due to oxygen starvation, and the patient feels their vision failing - they see grey or everything becomes dark. Yet surprisingly they are able to hear quite well at this time because hearing is one of the last senses to fail.

Within 5-20 seconds the person is unconscious, can sense nothing and experience nothing. Their body is discovered and resuscitation with cardiac massage commences. About 1 in 5 (20%) of all people performing cardiac massage is so efficient their efforts generate a flow of blood around the body sufficient to restore consciousness. Sometimes this flow of blood is sufficient to restore normal consciousness, but usually it is just sufficient to restore some degree of consciousness, but not normal consciousness. Normal consciousness takes longer to return than it takes to restore pumping action of the heart.

Oxygen starvation of the eyes is somewhat reversed, restoring some central vision. At the same time, oxygen starvation, stress, and adrenaline administered as part of the resuscitation medication causes the pupils to be wide open - so patients see a bright light at the end of a tunnel. Furthermore, abnormal interpretation of bodily sensations, together with abnormal muscle spindle function generates sensations of movement and floating - so the person perceives themselves to be traveling down this tunnel towards the bright light. Restoration of entire retina function restores the ability to see light, but does not restore normal brain function, nor does it restore normal pupil size (adrenaline effect). So the person perceives themselves to be passing out of the tunnel into the light - they are "enveloped by the light".

At this same time, having passed into the light, while consciousness is gradually returning, but still abnormal, a person may undergo wondrous hallucinatory experiences. Such experiences are partly delusory due to misinterpretation of bodily sensations, sometimes due to abnormal electrical activity in parts of the brain such as the hippocampus which is very sensitive to oxygen starvation. The latter can also generate sensations of life review, while abnormal electrical activity in the rest of the temporal lobe can also generate sensations of immaterial presences, or of religious figures.

The resuscitation progresses, and consciousness returns to near normal. The resuscitating doctors and nurses speak, and what they say, what they do, and all other sounds are heard by the patient, while still paralyzed due to oxygen starvation and apparently unconscious. The doctors and the nurses regularly open the eyes of the patient to shine a light into the eyes to check papillary reactions to light. And sometimes the eyes of a patient remain open during resuscitation. So some patients can see what is happening around their bodies during their resuscitation. These sensations, combined with abnormal sensory information from muscle spindles, combined with abnormal interpretation of muscle spindle sensations can generate sensations of displacement and movement out of the body - all these things combine to generate out of body experiences during which the person sees and hears everything occurring to their body and around their body. Failure of prefrontal function means they still feel calm and serene at this time, as well as indifferent to pain.

Finally, resuscitation is successful - normal pumping action of the heart is restored, and the person eventually awakens. Some people remember all these wondrous experiences, and tell others what happened during the period they lay still and motionless, apparently unconscious, during the resuscitation for their cardiac arrest

 

Conclusion

So supernatural or paranormal explanations are not needed to explain what those undergoing near death experiences during resuscitation for cardiac arrest experience. Nor are explanations such as a soul, or a mind which exists separately from the body required. The functioning of the body explains all aspects of near death experiences in survivors of cardiac arrest.

 

References:

1. Aminoff MJ, et al, (1988), Electrocerebral accompaniments of syncope associated with malignant ventricular arrhythmias. Annals of Internal Medicine, 108: 791-796.
2. Christensen SF, et al, (1990), Estimation of cerebral blood flow during cardiopulmonary resuscitation in humans. Resuscitation, 19: 115-123.
3. Clute HL, Levy WJ, (1990), Electroencephalographic changes during brief cardiac arrest in humans. Anesthesiology, 73: 821-825.
4. Guercio LRM del, et al, (1963), Cardiac output and other hemodynamic variables during external cardiac massage in man. New England Journal of Medicine, 269: 1398-1404.
5. Guercio LRM del, et al (1965), Comparison of blood flow during internal and external cardiac massage in man. Circulation, 31: supplement 1: 171-180.
6. Kouwenhoven WB, Jude JR, Knickerbocker GG, (1960), Closed-chest cardiac massage. Journal of the American Medical Association, 173: 1064.
7. Lewinter, J.R., et al, (1989), CPR-dependant consciousness: Evidence for cardiac compression causing forward flow. Annals of Emergency Medicine, 18: 1111-1115.
8. Liere van EJ, Stickney JC, (1963), Hypoxia, published University of Chicago Press, page 317.
9. Liu, P., et al, (2002), Pump models assessed by transoesophageal echocardiography during cardiopulmonary resuscitation. Chinese Medical Journal, 115: 359-363.
10. Lommel P. van, et al, (2001), Near death experiences in survivors of cardiac arrest: a prospective study in the Netherlands. Lancet, 358: 2039-2045.
11. Losasso TJ, et al, (1992), Electroencephalographic monitoring of cerebral function during asystole and succesful cardiopulmonary resuscitation. Anesthesia and Analgesia, 75: 12-19.
12. MacKenzie, G.J., et al, (1964), Haemodynamic effects of external cardiac compression. Lancet, I: 1342-1345.
13. McDonald, J.L., (1982), Systolic and mean arterial pressures during manual and mechanical CPR in humans. Annals of Emergency Medicine, 11: 292-295.
14. Oriol, A., Smith, H.J., (1968), Hemodynamic observations during closed chest cardiac massage. Canadian Medical Association Journal, 98: 841-843.
15. Rossen R, et al, (1943), Acute arrest of cerebral circulation in man. Archives of Neurology and Psychiatry, 50: 510-528.
16. Swenson, R.D., et al., (1988), Hemodynamics in humans during conventional and experimental methods of cardiopulmonary resuscitation. Circulation, 78: 630-639.
17. Wei, J., et al., (2006), Cardiopulmonary resuscitation in the prone position: A simplified method for outpatients. Journal of the Chinese Medical Association, 69: 202-206.

 

 

 

 

Copyright G.M. Woerlee, 19 February 2010