G Model
ARTICLE IN PRESS
RESUS 6155 1–2
Resuscitation xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Editorial
2
“AWAREness during CPR: Be careful with what you say!”
3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
During cardiac arrest (CA), the clinical criteria for death (ie, no cardiac output, no respirations, and fixed and dilated pupils) are reached for a variable period of time, and loss of brain function eventually ensues.1 In that particular moment, or right after a CA, when cerebral blood flow and electrical brain activity are impaired or null, some patients experience a wide range of subjective phenomena, such as “seeing a tunnel”, a “bright light”, a “mystical being”, “feelings of peace”, and “out-of-body experiences”, in which people describe a feeling of separation from their bodies, as well as awareness of things during the episode or event.1–4 These descriptions have been known for centuries. In 1740, PierreJean du Monchaux, described a case of a near-death febrile patient who experienced similar features.5 The patient underwent several phlebotomies and during one of the last phlebotomies, he lost consciousness for a significant period of time, and then “he saw an extremely bright light and thought he was in heaven”.5 Moody, in his book Life after life, collected all the experiences from 150 people who had been close to death.4 He used for the first time, the term near-death experiences (NDE) for the recurring features noted in these survivors. Moody’s observations were not limited to CA survivors, but included people who were considered sufficiently ill to have died without medical intervention. NDEs have been reported in up to 12–18% of CA survivors, and they have been compared to the experience reported in patients undergoing general anesthesia.1,6 However, this information cannot be fully extrapolated, as during CA there is a significant decrease or absent cerebral function and blood flow, that is not seen in patients undergoing general anesthesia.7 Some studies have suggested that this “consciousness/awareness” in patients during CA, may be present, despite clinically undetectable signs of being awake, while others have hypothesized that there may be a surge of electrical activity even after a CA.1,3 The explanation for this phenomenon remains unclear. There are several theories regarding the origin or causation of NDEs, but none of them have been proven.1,2 Greyson and Stevenson led one of the first systematic studies on NDEs in 1980, where they retrospectively reviewed 78 patients using subjective narratives and questionnaires, interviews, and medical records of these survivors.8 Based on their findings, they suggested that social environments, cultural factors, and previous beliefs of death, could explain some of the features of the experiences described. Others investigators have suggested that NDEs were associated to religious beliefs, level of education, and psychological responses to the fear of impending death.8–10 The exact mechanism(s) of
awareness during resuscitation attempts (while the patient is “dead”) remain(s) unknown. One of the most accepted theories on NDEs, is a disturbance in brain chemistry when the brain blood flow is supposed to be completely null.1–3,10 Endorphins, hypercarbia, specific receptor alterations, and many others, have been proposed as potential causative mediators.10–12 However, Parnia and coworkers in 2001, reported no biochemical evidence to support the role of drugs, hypoxia, hypercarbia or electrolyte disturbances in the pathogenesis of NDE.1 The results of these studies arise which possibly involves several of the mechanisms mentioned above. In this issue of Resuscitation, the clinical research group led by Parnia and collaborators, report the results of a four-year, multicenter, observational study of patients that underwent cardiopulmonary resuscitation (CPR) that survived a CA and had NDEs.13 This study surprisingly revealed that 2% of interviewed survivors, had full awareness according to the 16-item Greyson’s NDE scale (which is mainly focused in thought processes and subjective feelings). These investigators also evaluated the feasibility of a newer, objective measure of explicit visual and auditory awareness/perception, which are included in the broad term of NDEs and have not been studied in detail. This study was elegantly done with careful attention to avoid clinician-introduced bias employed. Despite the fact that there was a relatively low incidence of visual (VA) and auditory awareness, there was a patient that was able to specifically demonstrate full awareness during the event (by accurately describing people, sounds and activities). Could this patient have had recall bias? The majority of interviews were conducted from 3 months and up to 1 year after the event. Some could argue that such lapse could be responsible for the NDEs. However, there is data to suggest that this result might not be influenced by the time the interview was held. Greyson inquired the consistency of NDE over two decades and concluded that there was no statistical significance in a 19-year period of time between the interviews.14 NDEs will continue to be present in survivors of CA. The experiences may cause fear and a post-traumatic stress disorder in some patients. Healthcare providers at the present time cannot identify which patients will have such recall. Therefore, every effort must be made to assure resuscitation attempts to be professional without making any “remarks” that may be heard by the victim (such as inappropriate jokes). We believe that more well-designed clinical trials, aimed to explicitly measure visual and auditory awareness during CA, are required to answer the issue of conscious awareness during CPR. These trials must include quality and duration of CPR,
http://dx.doi.org/10.1016/j.resuscitation.2014.09.023 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Olvera-Lopez E, Varon J. “AWAREness during CPR: Be careful with what you say!”. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.09.023
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
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measurement of various neurotransmitters, previous medical conditions that may alter the patient’s mental status, medications taken prior the event and baseline psychological profile. For now, and until those trials are designed and completed, health care providers must consider the possibility of full or partial conscious awareness during resuscitation maneuvers.
98
References
92 93 94 95 96
10. Blackmore SJ. Near death experiences. J R Soc Med 1996;89:73–6. 11. Carr DB. Endorphins at the approach of death. Lancet 1981;1:390. 12. Jansen K. Near death experiences and the NMDA receptor. Br Med J 1989;298:1708. 13. Parnia S, Spearpoint K, de Vos G, et al. AWARE – AWAreness during Resuscitation – a prospective study. Resuscitation 2014 (in this issue). 14. Greyson B. Consistency of near-death experience accounts over two decades: are reports embellished over time? Resuscitation 2007;73:407–11.
Edgardo Olvera-Lopez a,b Q1 Universidad Autónoma de San Luis Potosi, Mexico Q2 b Dorrington Medical Associates, Houston, TX, USA
a 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
1. Parnia S, Waller DG, Yeates R, Fenwick P. A qualitative and quantitative study of the incidence, features and etiology of near death experiences in cardiac arrest survivors. Resuscitation 2001;48:149–56. 2. Buunk G, van der Hoeven JG, Meinders AE. Cerebral blood flow after cardiac arrest. Neth J M 2000;57:106–12. 3. Bennet DR, Nord NM, Roberts TS. Prolonged “survival” with flat EEG following CA. Electroencephalogr Clin Neurophysiol 1971;30:94. 4. Moody RA. Life after fife: the investigation of a phenomenon – survival of bodily death. 1st ed. Atlanta: Mockingbird Books; 1975. p. 125. 5. Charlier P. Oldest medical description of a near death experience (NDE), France, 18th century. Resuscitation 2014;85:e155. 6. Greyson B. The near-death experience scale. Construction, reliability, and validity. J Nerv Ment Dis 1983;171:369–75. MM. Awareness during anaesthesia. Anesthesiology 7. Ghoneim 2000;92:597–602. 8. Greyson B, Stevenson I. The phenomenology of near death experiences. Am J Psychiatry 1980;137:1193–6. 9. Kellehear A. A culture, biology, and the near death experience. J Nerv Ment Dis 1993;181:148–56.
Varon a,b,c,∗
a
Joseph The University of Texas Health Science Center at Houston, USA b The University of Texas Medical Branch at Galveston, USA c University General Hospital, Houston, TX, USA
∗ Corresponding
author at: 2219 Dorrington Street, Houston, TX 77030, USA. E-mail addresses: [email protected], [email protected] (J. Varon). 28 September 2014
Please cite this article in press as: Olvera-Lopez E, Varon J. “AWAREness during CPR: Be careful with what you say!”. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.09.023
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ARTICLE IN PRESS
RESUS 6155 1–2
Resuscitation xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Editorial
2
“AWAREness during CPR: Be careful with what you say!”
3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
During cardiac arrest (CA), the clinical criteria for death (ie, no cardiac output, no respirations, and fixed and dilated pupils) are reached for a variable period of time, and loss of brain function eventually ensues.1 In that particular moment, or right after a CA, when cerebral blood flow and electrical brain activity are impaired or null, some patients experience a wide range of subjective phenomena, such as “seeing a tunnel”, a “bright light”, a “mystical being”, “feelings of peace”, and “out-of-body experiences”, in which people describe a feeling of separation from their bodies, as well as awareness of things during the episode or event.1–4 These descriptions have been known for centuries. In 1740, PierreJean du Monchaux, described a case of a near-death febrile patient who experienced similar features.5 The patient underwent several phlebotomies and during one of the last phlebotomies, he lost consciousness for a significant period of time, and then “he saw an extremely bright light and thought he was in heaven”.5 Moody, in his book Life after life, collected all the experiences from 150 people who had been close to death.4 He used for the first time, the term near-death experiences (NDE) for the recurring features noted in these survivors. Moody’s observations were not limited to CA survivors, but included people who were considered sufficiently ill to have died without medical intervention. NDEs have been reported in up to 12–18% of CA survivors, and they have been compared to the experience reported in patients undergoing general anesthesia.1,6 However, this information cannot be fully extrapolated, as during CA there is a significant decrease or absent cerebral function and blood flow, that is not seen in patients undergoing general anesthesia.7 Some studies have suggested that this “consciousness/awareness” in patients during CA, may be present, despite clinically undetectable signs of being awake, while others have hypothesized that there may be a surge of electrical activity even after a CA.1,3 The explanation for this phenomenon remains unclear. There are several theories regarding the origin or causation of NDEs, but none of them have been proven.1,2 Greyson and Stevenson led one of the first systematic studies on NDEs in 1980, where they retrospectively reviewed 78 patients using subjective narratives and questionnaires, interviews, and medical records of these survivors.8 Based on their findings, they suggested that social environments, cultural factors, and previous beliefs of death, could explain some of the features of the experiences described. Others investigators have suggested that NDEs were associated to religious beliefs, level of education, and psychological responses to the fear of impending death.8–10 The exact mechanism(s) of
awareness during resuscitation attempts (while the patient is “dead”) remain(s) unknown. One of the most accepted theories on NDEs, is a disturbance in brain chemistry when the brain blood flow is supposed to be completely null.1–3,10 Endorphins, hypercarbia, specific receptor alterations, and many others, have been proposed as potential causative mediators.10–12 However, Parnia and coworkers in 2001, reported no biochemical evidence to support the role of drugs, hypoxia, hypercarbia or electrolyte disturbances in the pathogenesis of NDE.1 The results of these studies arise which possibly involves several of the mechanisms mentioned above. In this issue of Resuscitation, the clinical research group led by Parnia and collaborators, report the results of a four-year, multicenter, observational study of patients that underwent cardiopulmonary resuscitation (CPR) that survived a CA and had NDEs.13 This study surprisingly revealed that 2% of interviewed survivors, had full awareness according to the 16-item Greyson’s NDE scale (which is mainly focused in thought processes and subjective feelings). These investigators also evaluated the feasibility of a newer, objective measure of explicit visual and auditory awareness/perception, which are included in the broad term of NDEs and have not been studied in detail. This study was elegantly done with careful attention to avoid clinician-introduced bias employed. Despite the fact that there was a relatively low incidence of visual (VA) and auditory awareness, there was a patient that was able to specifically demonstrate full awareness during the event (by accurately describing people, sounds and activities). Could this patient have had recall bias? The majority of interviews were conducted from 3 months and up to 1 year after the event. Some could argue that such lapse could be responsible for the NDEs. However, there is data to suggest that this result might not be influenced by the time the interview was held. Greyson inquired the consistency of NDE over two decades and concluded that there was no statistical significance in a 19-year period of time between the interviews.14 NDEs will continue to be present in survivors of CA. The experiences may cause fear and a post-traumatic stress disorder in some patients. Healthcare providers at the present time cannot identify which patients will have such recall. Therefore, every effort must be made to assure resuscitation attempts to be professional without making any “remarks” that may be heard by the victim (such as inappropriate jokes). We believe that more well-designed clinical trials, aimed to explicitly measure visual and auditory awareness during CA, are required to answer the issue of conscious awareness during CPR. These trials must include quality and duration of CPR,
http://dx.doi.org/10.1016/j.resuscitation.2014.09.023 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Olvera-Lopez E, Varon J. “AWAREness during CPR: Be careful with what you say!”. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.09.023
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
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ARTICLE IN PRESS Editorial / Resuscitation xxx (2014) xxx–xxx
2
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measurement of various neurotransmitters, previous medical conditions that may alter the patient’s mental status, medications taken prior the event and baseline psychological profile. For now, and until those trials are designed and completed, health care providers must consider the possibility of full or partial conscious awareness during resuscitation maneuvers.
98
References
92 93 94 95 96
10. Blackmore SJ. Near death experiences. J R Soc Med 1996;89:73–6. 11. Carr DB. Endorphins at the approach of death. Lancet 1981;1:390. 12. Jansen K. Near death experiences and the NMDA receptor. Br Med J 1989;298:1708. 13. Parnia S, Spearpoint K, de Vos G, et al. AWARE – AWAreness during Resuscitation – a prospective study. Resuscitation 2014 (in this issue). 14. Greyson B. Consistency of near-death experience accounts over two decades: are reports embellished over time? Resuscitation 2007;73:407–11.
Edgardo Olvera-Lopez a,b Q1 Universidad Autónoma de San Luis Potosi, Mexico Q2 b Dorrington Medical Associates, Houston, TX, USA
a 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
1. Parnia S, Waller DG, Yeates R, Fenwick P. A qualitative and quantitative study of the incidence, features and etiology of near death experiences in cardiac arrest survivors. Resuscitation 2001;48:149–56. 2. Buunk G, van der Hoeven JG, Meinders AE. Cerebral blood flow after cardiac arrest. Neth J M 2000;57:106–12. 3. Bennet DR, Nord NM, Roberts TS. Prolonged “survival” with flat EEG following CA. Electroencephalogr Clin Neurophysiol 1971;30:94. 4. Moody RA. Life after fife: the investigation of a phenomenon – survival of bodily death. 1st ed. Atlanta: Mockingbird Books; 1975. p. 125. 5. Charlier P. Oldest medical description of a near death experience (NDE), France, 18th century. Resuscitation 2014;85:e155. 6. Greyson B. The near-death experience scale. Construction, reliability, and validity. J Nerv Ment Dis 1983;171:369–75. MM. Awareness during anaesthesia. Anesthesiology 7. Ghoneim 2000;92:597–602. 8. Greyson B, Stevenson I. The phenomenology of near death experiences. Am J Psychiatry 1980;137:1193–6. 9. Kellehear A. A culture, biology, and the near death experience. J Nerv Ment Dis 1993;181:148–56.
Varon a,b,c,∗
a
Joseph The University of Texas Health Science Center at Houston, USA b The University of Texas Medical Branch at Galveston, USA c University General Hospital, Houston, TX, USA
∗ Corresponding
author at: 2219 Dorrington Street, Houston, TX 77030, USA. E-mail addresses: [email protected], [email protected] (J. Varon). 28 September 2014
Please cite this article in press as: Olvera-Lopez E, Varon J. “AWAREness during CPR: Be careful with what you say!”. Resuscitation (2014), http://dx.doi.org/10.1016/j.resuscitation.2014.09.023
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