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Near-death experiencesSIR,-Dr Owens and colleagues (Nov 10, p 1175) report aninvestigation of near-death experiences (NDE). I am a physician ina busy district hospital where patients are treated everyday for life-threatening conditions. I have been aware of published reports ofNDE for about eight years. I agree that doctors are very reluctant todiscuss NDE and that most reports are outside mainstream medical

journals. One of the reasons for scepticism is the consistentreference to NDE during cardiac arrest. Sabom’ and Morse andcolleagues2 have compared data from case notes with patients’autoscopic experiences while apparently dead or near death.

Although there are some striking correlations there are manydiscrepancies. Because of accurate portrayal of hospital life ontelevision many people admitted to hospital might have seen a veryaccurate representation of a cardiac arrest, and retrospective studiesmight recruit patients whose memories could have been influencedby such programmes. I have come across only one case during aninvestigation that included a patient who had had hypothermiccoronary artery bypass surgery.

I have often asked patients with life-threatening hypoglycaemia(unrecognised and deep unconsciousness) about their memoriesduring coma since this is as near to death as many of the recordedinstances of NDE. I have not come across any who has had an NDEor indeed remembers anything, although NDE has been reportedwith ketoacidosis.2 I undertook a small survey in my diabetic clinicto identify patients who had had severe hypoglycaemia during thepast two years. Six patients had been admitted to hospital and noneof these had any recall of that time. Of the remaining thirteenpatients, two thought they had improved cognitive function withclarity of colours and thought, although they were unable torecognise their hypoglycaemia. The main thrust of Owens andcolleagues’ argument is that there can be improved cognitivefunction near death, although the reverse would be expected.Clearly the perceived improvement of cognitive function could befalse, as it was in the hypoglycaemic patients. If, as Owens et alconclude, their data might lead to a transcendental interpretation ofNDE I feel I should have identified at least one patient who had anNDE during severe hypoglycaemic coma.

I suspect that any life-threatening metabolic abnormality mightlead a patient to believe that they have heightened cognitivefunction, and hypoglycaemia is but one example. I also believe thatNDE is brain based and that it does not occur in hypoglycaemiabecause the brain and mental processes do not function at that time.If further research is planned, out-of-the-body experience (OOBE)is probably a better model for the investigation of cognitivefunction. I suspect many of the experiences described as NDE areOOBE. OOBE is much more common than NDE, is associatedwith improved cognitive function, and lacks the life review andbeing of light aspects. It can apparently sometimes be induced atwill and is more appropriate for psychological testing.3Mount Vernon Hospital,Northwood, Middlesex HA6 2RN, UK D. J. B. THOMAS

1. Sabom M. Recollections of death: a medical investigation. New York: Harper Row,1982.

2. Morse M, Castillo P, Venecia D, et al. Childhood near death experiences. Am J DisChild 1986; 140: 1110-13.

3. Blackmore SJ. Beyond the body. an investigation of out of the body experiences.London: Granada, 1983.

SIR,-Dr Owens and his colleagues describe seven commonlyreported features of the near death experience (NDE). One of these,the belief that one had left one’s body (also known as the "out of thebody experience" [OBE]), was a consistent finding in 68% of cases.I report a patient undergoing respiratory psychophysiologicalinvestigation in our department, who voluntarily had an OBE. Themechanism demonstrated might further elucidate some or all of theother features of the NDE.A 53-year-old woman was referred by her general practitioner for

chronic fatigue syndrome. She described 5 years of severeexhaustion after a viral illness. She also had difficulty in focusing,sudden wakening in the middle of the night, paraesthesiae of thefinger tips, gasping and difficulty in taking a deep breath, sharp

pains in the left chest, and palpitations. Further questioningrevealed that the patient had not been well before she had the viralillness. She had had a very disturbed childhood-she had witnessedher father’s suicide when she was 6 and the death of her motherthree weeks later. After a difficult marriage to a man who proved tobe bisexual, she pursued a very busy career in the film industry. Shelived in the "fast lane" for several years, smoking 20 cigarettes a day,drinking a bottle of wine a day, and having many lovers. She felt thatthis life-style contributed to the exhaustion that preceded her viralillness. She had brisk reflexes but nothing else of note. A workingdiagnosis of effort syndrome (exhaustion and hyperventilationsecondary to effort and distress beyond physiological tolerance) wasmade. 1

Clinical capnography was done and showed a low normal restingend-tidal partial pressure of carbon dioxide (PeCO,) at 33 mm Hgand normal recovery after a 3 minute forced hyperventilationprovocation test (FHPT), the recovered value being 25 mm Hg.However, recollection of personal stressors—in this patientthinking about her dying brother-produced a fall in P ’CO, to 25mm Hg, clearly corroborative of the clinical diagnosis. The patientthen had an OBE. She felt that she left her body and saw it below heras she struggled to travel to France to visit her brother. She primedherself for the OBE by having a 20 second breath hold, followed byprofound hyperventilation, with Pe COZ falling to 20 mm Hg.

This report shows that, in this patient, hyperventilation probablymediated her OBE. It is well known that hyperventilation (the effectof which can be accentuated by a preliminary breath hold) canproduce a wide range of neurological and psychological effects byalkalosis-induced cerebral vasoconstriction and the Bohr effect .3,4In addition, these same mechanisms could readily explain enhancedperception of light, sense of being in a tunnel, and altered cognitionand emotions. Further, the sense of impending death is a frequentfeature of hyperventilation-induced panic attacks. Finally, it isworth remembering that NDEs often occur in patients successfullyresuscitated after cardiac arrest, an event often contributed to byhyperventilation-induced coronary vasoconstriction and

arrhythmia.s 5

Cardiac Department,Charing Cross Hospital,London W6 8RF, UK STUART D. ROSEN

1. Rosen SD, King JC, Nixon PGF. Is chronic fatigue syndrome synonymous with effortsyndrome? J R Soc Med 1990; 83: 761-65.

2. Nixon PGF, Freeman LJ. The ’think test’: a further technique to elicit

hyperventilation. J R Soc Med 1988; 81: 277-79.3. Lum LC. The syndrome of chronic habitual hyperventilation. In: Hill OW, ed.

Modem trends in psychosomatic medicine, 3. London Butterworth, 19764. Wyke B. Brain function and metabolic disorders. London: Butterworth, 1963.5. Lum LC, Nixon PGF. Endorphms, I presume, or hyperventilation? Lancet 1981; r

160.

Disaster epidemiologySiR,—Your Oct 6 editorial (p 845) states that "while severe

malnutrition is a major risk factor for death, communicable diseasesrather than starvation cause most morbidity and death amongrefugee communities". You do not, however, consider the

significance of high prevalence rates of moderate malnutrition indrought-affected communities,1,2 or the interactions betweenmalnutrition and communicable diseases .3We studied the association between light, moderate, and severe

wasting and the incidence of death during the southern Ethiopianfamine of 1985-86. 24 communities from Arero and Borana

Provinces, containing about 10 000 children, were observedmonthly for prevalence of malnutrition and incidence of death.Severe wasting was defmed as weight/height less than 70% ofreference median, moderate as 70-80%, and light as 80-85%.Incidence of death was measured in the same communities.

Multiple linear regression was done of incidence of death one monthafter registration of degrees of wasting on prevalence of severe,moderate, and light malnutrition. The results confirm that factorsassociated with famine-relief shelters represent the main risk fordeath among children. However, they also show that moderatewasting may be a stronger predictor of death than severe wasting.Life in famine-relief shelters plus a high prevalence of moderate and