Arguments Against The Role of A Lack of Oxygen

The simplest problem with lack of oxygen as a theory is that there have been many NDEs reported in subjects who could not have had lower than normal oxygen levels. This is particularly true in the case of people who have reported having the experience just before a major accident. In these cases the experience may typically occur just a few instances before they actually have the accident which means that they could not have had a lack of oxygen at the time of the experience as there had not yet been any physical damage.

Another argument against the theory of a lack of oxygen comes from clinical medical practice. In hospitals it is very common to see patients suffering with the effects of reduced oxygen levels. This may occur due to many illnesses such as severe asthma or heart failure. In such cases when the levels of oxygen become reduced a clinical state known as an 'acute confusional state' develops which is very different to the 'near death experience'. In this condition individuals have 'clouding of consciousness' with highly confused and fragmented thought processes with little or no memory recall. Such experiences are not universal and tend to be different from individual to individual. If NDEs occurred as a result of a lack of oxygen to the brain then one would expect the hospital patients who suffer with a lack of oxygen either acutely or chronically to describe seeing some of the features of a NDE. However in clinical practice patients' with a lack of oxygen do not report seeing a light, a tunnel or describe the typical features of a NDE.

More support against the role of oxygen has recently come from a medical study carried out by our group in the coronary care, emergency, and medical units of Southampton General Hospital. This study examined near death experiences in cardiac arrest survivors and compared many of the proposed factors for the causation of NDEs, such as a lack of oxygen, excess carbon dioxide and the role of drugs. The patients who survived a cardiac arrest were divided into two groups based upon whether they had experienced a NDE. The factors listed above were compared in those who had the experience with those who did not. The study did not find any evidence to support the role of a lack of oxygen, excess carbon dioxide or drugs in causing the experiences, although it was concluded that a larger study was needed to provide definitive data.

Finally, examining some of the reports from mountaineers and airforce pilots who have described experiencing some of the features of a near death experience, it must be said that it would not be surprising that they may have these experiences. In the case of airforce pilots who accelerate at very high speeds this sudden acceleration may result in a sudden drop in blood circulating to the brain. It is therefore very similar to what happens to someone who is about to die with the lack of blood flow to the brain occurring either as a result of very heavy bleeding or the heart stopping. If the increased G forces (pressure) that had led to the experience continue there is also obviously a risk of death as there will be no blood flowing to the brain. As regards mountaineers, if the levels of oxygen in the air drop to very low levels at high altitude, then obviously the levels of oxygen in the blood of the mountaineers will also drop to very low levels. The lack of blood oxygen may potentially lead to a state, similar to that seen in people who are dying due to their lungs stopping to work. Therefore it would not be entirely surprising if they have very similar experiences, as the body of the mountaineer may also think that it is approaching death. At any rate in both cases the experiences are not entirely similar to the typically described near death experiences, although they may share some of the features.