Suspended animation

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Cardiopulmonary resuscitation (CPR) being performed on a trauma patient in a hospital of Maracay, Venezuela. Like CPR, suspended animation could delay the onset of cell death (necrosis) in seriously injured or ill patients, providing them with more time to receive definitive medical treatment. Intrahospital CPR.jpg
Cardiopulmonary resuscitation (CPR) being performed on a trauma patient in a hospital of Maracay, Venezuela. Like CPR, suspended animation could delay the onset of cell death (necrosis) in seriously injured or ill patients, providing them with more time to receive definitive medical treatment.

Suspended animation is the temporary (short- or long-term) slowing or stopping of biological function so that physiological capabilities are preserved. States of suspended animation are common in micro-organisms and some plant tissue, such as seeds. Many animals, including large ones, may undergo hibernation, and most plants have periods of dormancy. This article focuses primarily on the potential of large animals, especially humans, to undergo suspended animation.

Contents

In animals, suspended animation may be either hypometabolic or ametabolic in nature. It may be induced by either endogenous, natural or artificial biological, chemical or physical means. In its natural form, it may be spontaneously reversible as in the case of species demonstrating hypometabolic states of hibernation. When applied with therapeutic intent, as in deep hypothermic circulatory arrest (DHCA), usually technologically mediated revival is required. [1] [2]

Basic principles

Suspended animation is understood as the pausing of life processes by external or internal means without terminating life itself. [3] Breathing, heartbeat and other involuntary functions may still occur, but they can only be detected by artificial means. [4] For this reason, this procedure has been associated with a lethargic state in nature when animals or plants appear, over a period, to be dead but then can wake up or prevail without suffering any harm. This has been termed in different contexts hibernation, dormancy or anabiosis (the latter in some aquatic invertebrates and plants in scarcity conditions).

The revived microorganisms 13C and 15N incorporation in representative microbial cells.webp
The revived microorganisms

In July 2020, marine biologists reported that aerobic microorganisms (mainly), in "quasi-suspended animation", were found in organically-poor sediments, up to 101.5 million years old, 68.9 metres (226 feet) below the sea floor in the South Pacific Gyre (SPG) ("the deadest spot in the ocean"), and could be the longest-living life forms ever found. [5] [6]

Delayed resuscitation in humans

This condition of apparent death or interruption of vital signs in humans may be similar to a medical interpretation of suspended animation. It is only possible to recover signs of life if the brain and other vital organs suffer no cell deterioration, necrosis or molecular death principally caused by oxygen deprivation or excess temperature (especially high temperature). [7]

Some examples of people that have returned from this apparent interruption of life lasting over half an hour, two hours, eight hours or more while adhering to these specific conditions for oxygen and temperature have been reported and analysed in depth, but these cases are not considered scientifically valid. The brain begins to die after five minutes without oxygen; nervous tissues die intermediately when a "somatic death" occurs while muscles die over one to two hours following this last condition. [8]

It has been possible to obtain a successful resuscitation and recover life in some instances, including after anaesthesia, heat stroke, electrocution, narcotic poisoning, heart attack or cardiac arrest, shock, newborn infants, cerebral concussion, or cholera.

Supposedly, in suspended animation, a person technically would not die, as long as he or she were able to preserve the minimum conditions in an environment extremely close to death and return to a normal living state. An example of such a case is Anna Bågenholm, a Swedish radiologist who allegedly survived 80 minutes under ice in a frozen lake in a state of cardiac arrest with no brain damage in 1999. [9] [10]

Other cases of hypothermia where people survived without damage are:

Human hibernation

It has been suggested that bone lesions provide evidence of hibernation among the early human population whose remains have been retrieved at the Archaeological site of Atapuerca. In a paper published in the journal L’Anthropologie, researchers Juan-Luis Arsuaga and Antonis Bartsiokas point out that “primitive mammals and primates” like bush babies and lorises hibernate, which suggests that “the genetic basis and physiology for such a hypometabolism could be preserved in many mammalian species, including humans”. [15]

Since the 1970s, induced hypothermia has been performed for some open-heart surgeries as an alternative to heart-lung machines. Hypothermia, however, provides only a limited amount of time in which to operate and there is a risk of tissue and brain damage for prolonged periods.

There are many research projects currently investigating how to achieve "induced hibernation" in humans. [16] [17] This ability to hibernate humans would be useful for a number of reasons, such as saving the lives of seriously ill or injured people by temporarily putting them in a state of hibernation until treatment can be given.

The primary focus of research for human hibernation is to reach a state of torpor, defined as a gradual physiological inhibition to reduce oxygen demand and obtain energy conservation by hypometabolic behaviors altering biochemical processes. In previous studies, it was demonstrated that physiological and biochemical events could inhibit endogenous thermoregulation before the onset of hypothermia in a challenging process known as "estivation". This is indispensable to survive harsh environmental conditions, as seen in some amphibians and reptiles. [18]

Scientific possibilities

Temperature-induced

Lowering the temperature of a substance reduces its chemical activity by the Arrhenius equation. This includes life processes such as metabolism. Cryonics could eventually provide long-term suspended animation. [19]

Emergency Preservation and Resuscitation

Emergency Preservation and Resuscitation (EPR) is a way to slow the bodily processes that would lead to death in cases of severe injury. [20] This involves lowering the body's temperature below 34 °C (93 °F), which is the current standard for therapeutic hypothermia. [20]

Hypothermic experiments on animals

In June 2005, scientists at the University of Pittsburgh's Safar Center for Resuscitation Research announced they had managed to place dogs in suspended animation and bring them back to life, most of them without brain damage, by draining the blood out of the dogs' bodies and injecting a low temperature solution into their circulatory systems, which in turn keeps the bodies alive in stasis. After three hours of being clinically dead, the dogs' blood was returned to their circulatory systems, and the animals were revived by delivering an electric shock to their hearts. The heart started pumping the blood around the body, and the dogs were brought back to life. [21]

On 20 January 2006, doctors from the Massachusetts General Hospital in Boston announced they had placed pigs in suspended animation with a similar technique. The pigs were anaesthetized and major blood loss was induced, along with simulated - via scalpel - severe injuries (e.g. a punctured aorta as might happen in a car accident or shooting). After the pigs lost about half their blood the remaining blood was replaced with a chilled saline solution. As the body temperature reached 10 °C (50 °F) the damaged blood vessels were repaired and the blood was returned. [22] The method was tested 200 times with a 90% success rate. [23]

Chemically induced

The laboratory of Mark Roth at the Fred Hutchinson Cancer Research Center and institutes such as Suspended Animation, Inc are trying to implement suspended animation as a medical procedure which involves the therapeutic induction to a complete and temporary systemic ischemia, directed to obtain a state of tolerance for the protection-preservation of the entire organism, this during a circulatory collapse "only by a limited period of one hour". The purpose is to avoid a serious injury, risk of brain damage or death, until the patient reaches specialized attention. [24]

See also

Related Research Articles

Clinical death is the medical term for cessation of blood circulation and breathing, the two criteria necessary to sustain the lives of human beings and of many other organisms. It occurs when the heart stops beating in a regular rhythm, a condition called cardiac arrest. The term is also sometimes used in resuscitation research.

<span class="mw-page-title-main">Hypothermia</span> Human body core temperature below 35.0 °C (95.0 °F)

Hypothermia is defined as a body core temperature below 35.0 °C (95.0 °F) in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe hypothermia, there may be hallucinations and paradoxical undressing, in which a person removes their clothing, as well as an increased risk of the heart stopping.

<span class="mw-page-title-main">Drowning</span> Respiratory impairment resulting from being in or underneath a liquid

Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer assistance. After successful resuscitation, drowning victims may experience breathing problems, vomiting, confusion, or unconsciousness. Occasionally, victims may not begin experiencing these symptoms until several hours after they are rescued. An incident of drowning can also cause further complications for victims due to low body temperature, aspiration of vomit, or acute respiratory distress syndrome.

<span class="mw-page-title-main">Reperfusion injury</span> Tissue damage after return of blood supply following ischemia or hypoxia

Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue after a period of ischemia or lack of oxygen. The absence of oxygen and nutrients from blood during the ischemic period creates a condition in which the restoration of circulation results in inflammation and oxidative damage through the induction of oxidative stress rather than restoration of normal function.

<span class="mw-page-title-main">Hypovolemic shock</span> Medical condition

Hypovolemic shock is a form of shock caused by severe hypovolemia. It could be the result of severe dehydration through a variety of mechanisms or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure.

<span class="mw-page-title-main">Cerebral hypoxia</span> Oxygen shortage of the brain

Cerebral hypoxia is a form of hypoxia, specifically involving the brain; when the brain is completely deprived of oxygen, it is called cerebral anoxia. There are four categories of cerebral hypoxia; they are, in order of increasing severity: diffuse cerebral hypoxia (DCH), focal cerebral ischemia, cerebral infarction, and global cerebral ischemia. Prolonged hypoxia induces neuronal cell death via apoptosis, resulting in a hypoxic brain injury.

<span class="mw-page-title-main">Brain ischemia</span> Medical condition

Brain ischemia is a condition in which there is insufficient bloodflow to the brain to meet metabolic demand. This leads to poor oxygen supply or cerebral hypoxia and thus leads to the death of brain tissue or cerebral infarction/ischemic stroke. It is a sub-type of stroke along with subarachnoid hemorrhage and intracerebral hemorrhage.

Deep hypothermic circulatory arrest (DHCA) is a surgical technique in which the temperature of the body falls significantly and blood circulation is stopped for up to one hour. It is used when blood circulation to the brain must be stopped because of delicate surgery within the brain, or because of surgery on large blood vessels that lead to or from the brain. DHCA is used to provide a better visual field during surgery due to the cessation of blood flow. DHCA is a form of carefully managed clinical death in which heartbeat and all brain activity cease.

Erika Nordby, also known as Baby Erika, Miracle Baby and Canada's Miracle Child, is a Canadian originally from Edmonton, Alberta known for having been revived after spending two hours without a heartbeat due to hypothermia. Nordby, then a 13-month-old toddler, had left her heated house nearly naked, while the air temperature was −24 °C (−11 °F).

<span class="mw-page-title-main">Effects of high altitude on humans</span> Environmental effects on physiology and mental health

The effects of high altitude on humans are mostly the consequences of reduced partial pressure of oxygen in the atmosphere. The medical problems that are direct consequence of high altitude are caused by the low inspired partial pressure of oxygen, which is caused by the reduced atmospheric pressure, and the constant gas fraction of oxygen in atmospheric air over the range in which humans can survive. The other major effect of altitude is due to lower ambient temperature.

Targeted temperature management (TTM) previously known as therapeutic hypothermia or protective hypothermia is an active treatment that tries to achieve and maintain a specific body temperature in a person for a specific duration of time in an effort to improve health outcomes during recovery after a period of stopped blood flow to the brain. This is done in an attempt to reduce the risk of tissue injury following lack of blood flow. Periods of poor blood flow may be due to cardiac arrest or the blockage of an artery by a clot as in the case of a stroke.

The Arctic Sun Temperature Management System is a non-invasive targeted temperature management system. It modulates patient temperature by circulating chilled water in pads directly adhered to the patient's skin. Using varying water temperatures and a computer algorithm, a patient's body temperature can be better controlled. It is produced by Medivance, Inc. of Louisville, Colorado.

Mild total body hypothermia, induced by cooling a baby to 33-34°C for three days after birth, is nowadays a standardized treatment after moderate to severe hypoxic ischemic encephalopathy in full-term and near to fullterm neonates. It has recently been proven to be the only medical intervention which reduces brain damage, and improves an infant's chance of survival and reduced disability.

Anna Elisabeth Johansson Bågenholm is a Swedish radiologist from Vänersborg, who survived after a skiing accident in 1999 left her trapped under a layer of ice for 80 minutes in freezing water. During this time she experienced extreme hypothermia and her body temperature decreased to 13.7 °C (56.7 °F), one of the lowest survived body temperatures ever recorded in a human with accidental hypothermia. Bågenholm was able to find an air pocket under the ice, but experienced circulatory arrest after 40 minutes in the water.

A hypothermia cap is a therapeutic device used to cool the human scalp. Its most prominent medical applications are in preventing or reducing alopecia in chemotherapy, and for preventing cerebral palsy in babies born with neonatal encephalopathy caused by hypoxic-ischemic encephalopathy (HIE). It can also be used to provide neuroprotection after cardiac arrest, to inhibit stroke paralysis, and as cryotherapy for migraine headaches.

Hydrogen sulfide is produced in small amounts by some cells of the mammalian body and has a number of biological signaling functions. Only two other such gases are currently known: nitric oxide (NO) and carbon monoxide (CO).

Emergency Preservation and Resuscitation (EPR) is an experimental medical procedure where an emergency department patient is cooled into suspended animation for an hour to prevent incipient death from ischemia, such as the blood loss following a shooting or stabbing. EPR uses hypothermia, drugs, and fluids to "buy time" for resuscitative surgery. If successful, EPR may someday be deployed in the field so that paramedics can suspend and preserve patients for transport.

Lance B. Becker is an American physician and academic, specializing in emergency medicine and treatment for cardiac arrest, currently at Northwell Health. He is the chairman of the department of emergency medicine at North Shore University Hospital, as well as chair and professor of emergency medicine at Hofstra Northwell School of Medicine.

<span class="mw-page-title-main">Skin temperature</span> Temperature at the outer surface of a living body

Skin temperature is the temperature of the outermost surface of the body. Normal human skin temperature on the trunk of the body varies between 33.5 and 36.9 °C, though the skin's temperature is lower over protruding parts, like the nose, and higher over muscles and active organs. Recording skin temperature presents extensive difficulties. Although it is not a clear indicator of internal body temperature, skin temperature is significant in assessing the healthy function of skin. Some experts believe the physiological significance of skin temperature has been overlooked, because clinical analysis has favoured measuring temperatures of the mouth, armpit, and/or rectum. Temperatures of these parts typically are consistent with internal body temperature.

Post-cardiac arrest syndrome (PCAS) is an inflammatory state of pathophysiology that can occur after a patient is resuscitated from a cardiac arrest. While in a state of cardiac arrest, the body experiences a unique state of global ischemia. This ischemia results in the accumulation of metabolic waste which instigate the production of inflammatory mediators. If return of spontaneous circulation (ROSC) is achieved after CPR, then circulation resumes, resulting in global reperfusion and the subsequent distribution of the ischemia products throughout the body. While PCAS has a unique cause and consequences, it can ultimately be thought of as type of global ischemia-reperfusion injury. The damage, and therefore prognosis, of PCAS generally depends on the length of the patient's ischemic period; therefore the severity of PCAS is not uniform across different patients.

References

  1. ↑ "Suspended Animation". Medical-Dictionary.thefreedictionary.com.
  2. ↑ Asfar, P; Calzia, E; Radermacher, P (2014). "Is pharmacological, H2S-induced 'suspended animation' feasible in the ICU?". Crit Care. 18 (2): 215. doi: 10.1186/cc13782 . PMC   4060059 . PMID   25028804.
  3. ↑ Asfar, P. (2014). "Is pharmacological, H2S-induced 'suspended animation' feasible in the ICU?". Critical Care. 182 (2): 215. doi: 10.1186/cc13782 . PMC   4060059 . PMID   25028804.
  4. ↑ "How do frogs survive winter? Why don't they freeze to death?". Scientific American. 11 July 2014. Retrieved 3 June 2017.
  5. ↑ Wu, Katherine J. (28 July 2020). "These Microbes May Have Survived 100 Million Years Beneath the Seafloor - Rescued from their cold, cramped and nutrient-poor homes, the bacteria awoke in the lab and grew". The New York Times. Retrieved 31 July 2020.
  6. ↑ Morono, Yuki; et al. (28 July 2020). "Aerobic microbial life persists in oxic marine sediment as old as 101.5 million years". Nature Communications . 11 (3626): 3626. Bibcode:2020NatCo..11.3626M. doi:10.1038/s41467-020-17330-1. PMC   7387439 . PMID   32724059.
  7. ↑ "Molecular death is". Forensic Medicine_gradestack.com.{{cite journal}}: Cite journal requires |journal= (help)
  8. ↑ "Definition of suspended animation is". Forensic Medicine_gradestack.com. Archived from the original on 29 June 2018. Retrieved 6 June 2017.{{cite journal}}: Cite journal requires |journal= (help)
  9. ↑ "'Miracle' student survived his body being frozen solid" . independent.co.uk. 20 January 2016. Archived from the original on 25 May 2022. Retrieved 5 June 2017.
  10. ↑ Gilbert M, Busund R, Skagseth A, Nilsen P, Solbo J (2000). "Resuscitation from accidental hypothermia of 13.7°C with circulatory arrest". The Lancet . 355 (9201): 375–376. doi:10.1016/S0140-6736(00)01021-7. PMID   10665559. S2CID   54348869.
  11. ↑ Suspended Animation? How A Boy Survived 15 Minutes Trapped Under Ice In Frozen Lake at Medical Daily
  12. ↑ Japanese man in mystery survival at BBC News
  13. ↑ Eleva boy’s story part of national tour to honor Mayo Clinics 150 years Archived 11 May 2015 at the Wayback Machine Mayo Clinic
  14. ↑ Warick, Jason (23 February 2002). "'Miracle child' bears few scars one year after brush with death". Edmonton Journal. p. A3.
  15. ↑ Sullivan, R (2020). "Early humans may have hibernated" . Archived from the original on 25 May 2022. Retrieved 25 November 2021. This article refers to Bartsiokas, A. & Arsuaga, J. (2020). Hibernation in hominins from Atapuerca, Spain half a million years ago. L'Anthropologie, Volume 124, Issue 5
  16. ↑ New Hibernation Technique might work on humans | LiveScience at www.livescience.com
  17. ↑ Race to be first to 'hibernate' human beings - Times Online at www.timesonline.co.uk
  18. ↑ "Is Human Hibernation Possible?" (PDF). nature.berkeley.edu.{{cite journal}}: Cite journal requires |journal= (help)
  19. ↑ Tandy C (2014). The Prospect of Immortality − Fifty Years Later. Ria University Press, USA, ISBN   978-1-934297-21-6
  20. 1 2 Delbert, Caroline (20 November 2019). "Doctors Place Humans in True Suspended Animation for First Time". Popular Mechanics. Retrieved 29 September 2020.
  21. ↑ Mihm, Stephen (11 December 2005). "Zombie Dogs". The New York Times.
  22. ↑ Alam HB, Rhee P, Honma K, Chen H, Ayuste EC, Lin T, Toruno K, Mehrani T, Engel C, Chen Z (2006). "Does the rate of rewarming from profound hypothermic arrest influence the outcome in a swine model of lethal hemorrhage?". J Trauma. 60 (1): 134–146. doi:10.1097/01.ta.0000198469.95292.ec. PMID   16456447.
  23. ↑ "Doctors claim suspended animation success". The Sydney Morning Herald. 20 January 2006. Retrieved 10 October 2006.
  24. ↑ Bellamy, R; Safar, P; Tisherman, S. A; Basford, R; Bruttig, S. P; Capone, A; Dubick, M. A; Ernster, L; Hattler Jr, B. G; Hochachka, P; Klain, M; Kochanek, P. M; Kofke, W. A; Lancaster, J. R; McGowan Jr, F. X; Oeltgen, P. R; Severinghaus, J. W; Taylor, M. J; Zar, H (1996). "Suspended animation for delayed resuscitation. Crit Care Med. 1996 Feb;24(2 Suppl):S24-47". Critical Care Medicine. 24 (2 Suppl): S24–47. doi:10.1097/00003246-199602000-00046. PMID   8608704.
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