Brain Injury by oxygen deficiency or lack of oxygen

 

Causes of oxygen deficiency

A lack of oxygen in the brain can occur after:

  • Cardiac arrest (due to infarction / cardiac arrhythmia) and after prolonged resuscitation
  • Respiratory arrest, for example in the event of (near) drowning, suffocation or choking
  • Prolonged epileptic seizure / status epilepticus
  • Poisoning (smoke or toxic substances) see also intoxication
  • Serious lung problems
  • Attempted strangulation
  • Being buried (avalanche, rubble, earth, sand, etc.)
  • Asphyxia literally means 'not breathing' This leads to a lack of oxygen in the baby around birth, which can damage various organs in the body. See further down this page for more information. This lack of oxygen can lead to the same consequences as a lack of oxygen later in life
  • Choke challenge, choking games
  • Using too much laughing gas. Laughing gas blocks the glutamate receptor, a neurotransmitter that is involved in all kinds of processes in the brain. It causes a temporary lack of oxygen in the brain. With more intensive use, the damage can increase. A vitamin B12 deficiency can also lead to failure in the spinal cord. Leave laughing gas where it belongs: with the doctors to anesthetize you.

 

Officially, a CVA (stroke) is also a circulatory disorder of the central nervous system. In a stroke, however, the oxygen deficiency is limited to a part of the brain.

 

Three minutes of OXYGEN emergency supply

The heart pumps oxygenated blood throughout the body. Two pairs of large arteries branch throughout the brain. They bring a continuous flow of oxygen and glucose.

 

When there is a lack of oxygen in the brain, the brain first increases the blood supply.

In serious circumstances, this is not always sufficient. The brain has an emergency energy supply for about three minutes.
This also means that if resuscitation is not started within two minutes in the event of cardiac arrest, that supply will quickly be depleted. The result can be that damage occurs everywhere in the brain with
cognition and memory problems.
If the lack of oxygen has lasted longer, the memory problems become worse and those affected often have a form of
aphasia. In addition, all kinds of motor abnormalities can occur, such as tremors and/or paralysis.


A lack of oxygen from three to nine minutes can result in irreversible brain damage! In case of a cardiac arrest a CPR (Cardiopulmonary resuscitation) is best started within two minutes. 


An ischemic stroke occurs when a part of the brains die because of a blocked arteria which lead to a partial lack of oxygen. 

Damage in brain areas

The most vulnerable areas of the nervous system are:

 

  • Cerebral cortex, especially around the central sulcus. This is the central groove that vertically separates the frontal lobe from the brain areas behind it. Indicated in the image below with the red line:
  • Temporal lobe
  • Hippocampus / seahorse
  • Cerebellum or cerebellum
  • Basal ganglia + Brain stem
  • Thalamus
  • Spinal cord

 

Brain cells, kidney cells and liver cells are sensitive to oxygen deficiency.

 

Oxygen deficiency causes damage everywhere

Damage after oxygen deficiency occurs everywhere where blood normally flows. This is also called diffuse brain damage. Parts of the brain die, spread throughout the entire brain and this process continues as the minutes pass.

 

The cerebral cortex and temporal lobe/temporal lobe (near the temples) in particular are sensitive to oxygen deficiency, which can quickly damage cognition and memory.

 

An oxygen deficiency of three to nine minutes leads to irreversible brain damage.

NB! In the event of cardiac arrest, it is therefore best to start resuscitation within two minutes.

 

Possible consequences

Brain death
Coma
Vegetative state
Minimally conscious state (MBT) / Low conscious state (LBT)
Delirium

 

Neurological deficit

More information: Neurological deficit

 

Cognitive disorders

More information: Cognitive disorders

 

The difference in consequences is significant

The consequences of oxygen deficiency in the brain differ per person and per situation. One person will have mild residual symptoms, while another will no longer have any sense of life.


Nowadays, there is more attention for the cognitive damage that people suffer after oxygen deficiency. For example, cognitive screening is performed more often, because the memory in particular is affected so quickly.

 

Brain damage after cardiac arrest, infarction and arrhythmias

It is estimated that in eight out of ten successful resuscitations, i.e. the person survives, the patient becomes comatose and suffers brain damage. In addition to being a heart patient, this person is also a brain damage patient.


The question now is actually: to what extent do you call the resuscitation successful?

 

Prognoses depend on circumstances such as temperature (heat or cold), speed of starting resuscitation, expertise of the emergency worker(s), and the location of the person with cardiac arrest.
Is the person being resuscitated in a remote area or already in (near) a hospital?

 

For a patient who is in poor condition, with many additional complaints, the chance of success is considerably lower than for someone in good condition.

 

Failure to resuscitate means that the patient will die quickly. The patient will be unconscious within seconds.

 

Neurological problems after cardiac arrest

Neurological results of cardiac arrest survivors vary considerably, from complete recovery to life in a vegetative state.
Not only does oxygen and glucose deficiency cause damage to the brain. The loss of blood flow due to cardiac arrest and the subsequent restarting of the heartbeat, by means of cardiac massage or an AED shock, also causes damage to the brain.
In order to limit damage to the brain and organs as much as possible, the patient is cooled to a temperature of 33ºC and kept at this temperature for a day.
Neurologists are often asked to assess coma patients after cardiac arrest, in an attempt to predict the degree of recovery that may occur.
Patients who recover quickly after resuscitation usually do not pose a problem for the prognosis.

 

Patients with a short circulatory arrest who suffered from a milder degree of oxygen deficiency in the brain show characteristics of a
reversible metabolic encephalopathy. Reversible means that recovery can occur.

 

Recovery after a short coma

If there is a coma and it lasts a maximum of a few hours (on average twelve), patients show some physical, sensory and intellectual problems upon awakening. They may be confused or experience a gap in memory of a few hours to days. Recovery is usually quick and complete.

 

Incomplete recovery after severe oxygen deficiency

There are also patients with severe systemic anoxia-ischemia (anoxia = no oxygen / ischemia = oxygen deficiency in the blood). This causes structural damage, comparable to damage after a stroke. Patients in this group have usually been in a coma for at least twelve hours and upon awakening have persistent sensory, intellectual and motor problems, either in one area of ​​the brain (focal) or in multiple areas (multifocal) or spread throughout the brain (diffuse injury). Recovery is often incomplete and slow.

 

Severity of disabilities

Brain damage after cardiac arrest can cause changes in movement, perception, feeling and thinking.
Some patients are later able to lead an independent life at home despite remaining neurological problems (moderately disabled).
Some can even work again. Possibly with adjusted working hours and rest breaks.
Cognitive disorders can be subtle and often not immediately visible. However, these disorders can significantly affect the patient's daily activities, participation in society and quality of life.
Other survivors of resuscitation have become severely disabled and dependent on help. They usually live in a nursing home. Patients with greater diffuse damage (damage throughout the brain) can end up in a state of being awake but unconscious (vegetative state) or are brain dead.

 

Difference between anoxia, hypoxia, asphyxia and ischemia (ischemia)

Brain damage due to oxygen deficiency is called postanoxic and/or posthypoxic encephalopathy.
The terms anoxia and hypoxia are used interchangeably but are essentially different from a medical perspective. The word asphyxia is only used for oxygen deficiency around the time of birth.

  • Anoxia: a total lack oxygen deficiency in tissues and organs. 
  • Hypoxia: reduction or inadequate flow of oxygen in the blood. 
  • Asphyxia: oxygen deficiency around the time of birth. It literally means not breathing. It can be caused by a placental abruption or problems with the blood flow to the placenta such as a placental infarction.
  • Ischemia (sometimes still spelled as ischaemia) is insufficient blood flow and reduced blood supply to organs and body tissues, resulting in a shortage of oxygen and glucose.

NB! Damage is not always visible on an MRI scan. Demonstrable abnormalities on an MRI scan may sometimes only become visible after several days, but they may also disappear again.

 

Resuscitation or not? Be prepared!

If resuscitation is not performed, the patient will die quickly.
Studies in humans show that someone without blood flow to the brain loses consciousness within 4 to 10 seconds.


That is why you and your loved ones should always ask yourself the question: Resuscitation or not?


In order to make a good decision, it may be advisable to have a conversation with your treating (family) doctor, the nurse and your family.


Your treating doctor can tell you more about your situation from a medical point of view. You can discuss how to make a good choice with nurses, spiritual counselor or ethicist and of course your family.

 

Resuscitation? Then also take a resuscitation course.

Download an resuscitation app.
Make sure your phone is on speakerphone so that you can call emergancy telephone number at the same time.
Know that brain cells die after just three minutes of cardiac arrest.
Talk about it with your loved ones and make a choice together: whether or not to resuscitate.

 

One of the best-known neuropsychologists in the Netherlands, Jenny Palm, can get excited about the naive assumption that resuscitation, as a widely practiced popular skill, would save lives.

"People enter the hospital as heart patients and leave the hospital as brain injury patients."

She states the following in an interview:


"There is a resuscitation hype going on, the manly saving of people's lives after a cardiac arrest, without the question being asked how far you should go.
We now know that 95% of such resuscitations have a very poor outcome. There is all kinds of research that attributes the highest chance of success in resuscitation to intervention in the operating room, during an operation.
The interval between cardiac arrest and successful resuscitation is the shortest in the operating room. Everywhere else, resuscitation is performed with sometimes dangerously long intervals, which greatly reduces the chance of a full and complete recovery.
People are encouraged to take resuscitation courses so that at some point they can save their partner or someone else. The effect of this is twofold: those who cannot resuscitate are saddled with a feeling of guilt, but so are those who have resuscitated, when they often have to conclude that the person they have saved saved and then goes through life with serious brain damage.
Quality of life should be the criterion. As long as someone is recovering, nothing is too much to let the patient regain what has been lost with all kinds of tricks, but after that it is over and the patient and the entire social system around him or her can figure it all out for themselves".

 

What is the view of researchers?

 

Consciousness is lost within four to ten seconds after a cardiac arrest

Studies in humans show that consciousness is lost between 4 and 10 seconds without a heartbeat and cerebral perfusion. The electroencephalogram
(EEG or brain film) becomes isoelectric (flat line) after 10-30 seconds of asystole (no heartbeat).
Rossen R, Kabat H, Anderson JP. Acute arrest of cerebral circulation in man. Arch Neurol Psychiatr. 1943;50:510–528. [Google Scholar]
Pana R, Hornby L, Shemie SD, Dhanani S, Teitelbaum J. Time to loss of brain function and activity during circulatory arrest. J Crit Care. 2016;34:77–83.
Cardiac arrest can be seen as a cause of damage due to metabolic failure (metabolic damage) and/or structural damage (in the brain structures) in the central nervous system.

Brain injury as a result of cardiac arrest / resuscitation

One of the consequences of cardiac arrest is that it can lead to brain damage. This is caused by the temporary disruption of blood circulation. Since the brain tissue is not well-equipped to withstand this, brain damage can occur in this way. This is also called hypoxic-ischemic brain injury.

source: Life after survival of a cardiac arrest. The brain is the heart of the matter.' Moulaert V.R.M.P. (2014) (doctoral Thesis, Maastricht University.

Brain injury leading cause of death after resuscitation

'Brain injury after cardiac arrest is the leading cause of death in patients resuscitated after cardiac arrest and the leading cause of
long-term disability in those who survive the acute phase...'
Source: Sandroni C, Cronberg T, Sekhon M. Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis. Intensive Care Med. 2021 Dec;47(12):1393-1414. doi: 10.1007/s00134-021-06548-2. Epub 2021 Oct 27.
PMID: 34705079; PMCID: PMC8548866.
+
Koenig MA. Brain resuscitation and prognosis after cardiac arrest. Crit Care Clin. 2014 Oct;30(4):765-83. doi: 10.1016/j.ccc.2014.06.007. Epub 2014 Jul 30. PMID: 25257740.

Other factors that are important for a prognosis

When discussing prognosis and level of care, it is important to remember that brain injury caused by cardiac arrest is not the only cause of death or disability after cardiac arrest.
The overall outcome of cardiac arrest is the result of several additional factors.
In addition to organ failure, these include the prior health status before the cardiac arrest and the cause of the cardiac arrest.
source: Sandroni C, Cronberg T, Sekhon M. Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis. Intensive Care Med. 2021 Dec;47(12):1393-1414. doi: 10.1007/s00134-021-06548-2. Epub 2021 Oct 27.
PMID: 34705079; PMCID: PMC8548866.

The cause of brain damage after reanimation

'Brain injury after cardiac arrest is caused by initial ischemia (the initial cerebral perfusion disorder) and subsequent reperfusion of the brain after resuscitation.
In those admitted to the intensive care unit after cardiac arrest, this injury manifests as coma and is the leading cause of death and long-term disability'.
-
Source: Sandroni C, Cronberg T, Sekhon M. Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis. Intensive Care Med. 2021 Dec;47(12):1393-1414. doi: 10.1007/s00134-021-06548-2. Epub 2021 Oct 27.
PMID: 34705079; PMCID: PMC8548866.

Extended restrictions after resuscitation

'After surviving out-of-hospital cardiac arrest, many patients and partners experience extensive limitations in their level of functioning
and quality of life. Gender, age, and therapeutic hypothermia (cooling of the patient), among other factors, shape differences in the functioning of
patients in the long term'.
-
source: Wachelder EM, Moulaert VR, van Heugten C, Verbunt JA, Bekkers SC, Wade DT. Life after survival: long-term daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation. 2009 May;80(5):517-
22. doi: 10.1016/j.resuscitation.2009.01.020. Epub 2009 Mar 17. PMID: 19282084.

Lower quality of life / participation

'On average, three years after cardiac arrest, 74% of patients experienced a low level of participation in society compared to the general population.
More than 50% reported severe fatigue, 38% feelings of anxiety and/or depression and 24% a reduced quality of life. Caregivers reported stress-related reactions, feelings of anxiety and a lower quality of life'.
-
source: Wachelder EM, Moulaert VR, van Heugten C, Verbunt JA, Bekkers SC, Wade DT. Life after survival: long-term daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation. 2009;80:517–522.

Higher burden for healthcare providers

'Seventeen percent of caregivers reported a high caregiver burden, which was related to the patient's level of functioning'.
source: Wachelder EM, Moulaert VR, van Heugten C, Verbunt JA, Bekkers SC, Wade DT. Life after survival: long-term daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation. 2009 May;80(5):517-
22. doi: 10.1016/j.resuscitation.2009.01.020. Epub 2009 Mar 17. PMID: 19282084.

More attention should be paid to the cognitive consequences after resuscitation

Attention needed for cognitive problems in patients after out-of-hospital cardiac arrest. This is necessary.
In the Netherlands, only a minority of cardiologists and rehabilitation specialists routinely prescribe some form of cognitive screening for OHCA patients, although the majority underlines the value of cognitive screening in OHCA patients in an integrated care pathway.


(OHCA=out-of-hospital cardiac arrest)


source: Boyce LW, Goossens PH, Volker G, van Exel HJ, Vliet Vlieland TPM, van Bodegom-Vos L. Attention needed for cognitive problems in patients after out-of-hospital cardiac arrest: an inventory about daily rehabilitation care.
Neth Heart J. 2018 Oct;26(10):493-499. doi: 10.1007/s12471-018-1151-z. PMID: 30215169; PMCID: PMC6150874.

Two studies that assessed quality of life by telephone

Two studies on which the Heart Foundation, among others, bases itself with the conclusion that survivors of cardiac arrest experience a good quality of life, comparable to a reference population.

These are short telephone questionnaires.

NB this is not a neuropsychological examination.

  • Beesems SG, Wittebrood KM, de Haan RJ, Koster RW. Cognitive function and quality of life after successful resuscitation from cardiac arrest. Resuscitation. 2014 Sep;85(9):1269-74. doi: 10.1016/j.resuscitation.2014.05.027. Epub 2014 Jun 6. Erratum in: Resuscitation. 2015 Mar;88:165. PMID: 24909366. Two hundred and twenty patients (>18 years) who survived 6-12 months after out-of-hospital cardiac arrest (OHCA) and their relatives were interviewed by telephone with validated questionnaires (Short-form Health Survey) (SF-12), Modified Rankin Scale (MRS), Telephone Cognitive Interview Status (TICS) and Caregiver Strain Index (CSI). Of all patients, 45% had a normal physical and 90% a normal mental SF-12. Eighty-one percent had a normal MRS (MRS≤2).
  • Smith K, Andrew E, Lijovic M, Nehme Z, Bernard S. Quality of life and functional outcomes 12 months after out-of-hospital cardiac arrest. Circulation. 2015 Jan 13;131(2):174-81. doi: 10.1161/CIRCULATIONAHA.114.011200. Epub 2014 Oct 29. PMID: 25355914. Nine hundred and twenty-seven (13.2%) survived to hospital discharge, of whom 76 (8.2%) died within 12 months. Interviews were conducted with 697 (80.7%) patients or proxies, who were followed up by telephone interview, including the Glasgow Outcome Scale-Extended, the 12-item Short Form Health Survey, and the EuroQol. The majority (55.6%) of respondents had a good recovery on the Glasgow Outcome Scale-Extended≥7 (41.1% if patients who died after discharge were included and non-respondents were assumed to have a poor recovery).

23% survival rate outside the hospital

The survival of patients resuscitated outside the hospital is comparable within the regions studied in the Netherlands and is on average 23%.
source: Dutch Heart Foundation

https://hartstichting-hartstichting-portal-p01.s3.eu-central-1.amazonaws.com/s3fs-public/2022-11/boek-hartstichting-reanimatie-cijfersboek-2016.pdf?
VersionId=3ryeDwunauHIgBzBR9Tcszc8T439M3oC

Survival rate of 70+ in the Netherlands

In case a patient was already dead upon arrival of the ambulance or in case of a do-not-resuscitate declaration, this patient was not included in this analysis.

Traumatic resuscitations and resuscitations in which the ambulance personnel witnessed the cardiac arrest were also excluded.
The researchers then found a survival rate in the Netherlands of 12% until discharge in patients aged ≥ 70 years (70-79 years: 16%; ≥ 80 years: 8%, p=0.001). Of the surviving patients, 90% survived with a 'favorable neurological outcome'.
Neurological recovery was determined with the Cerebral Performance Category (CPC) scale based on hospital data;
CPC 1 stands for neurological recovery without residual damage,
CPC 2 for mild neurological problems,
CPC 3 for severe neurological problems,
CPC 4 for coma or vegetative state and
CPC 5 for death or brain death.
Patients with CPC 1 and 2 were classified as having ‘good neurological’ recovery.
Resuscitation-related factors and not comorbidity determine the outcome after OHCA in older patients.
The most important predictors, also in older and more ill patients, are the resuscitation factors: shockable initial rhythm, timely connection of a defibrillator, presence of a witness and bystander resuscitation.
The chance of survival after cardiac arrest outside the hospital becomes lower with increasing age.


source:
Beesems SG, Blom MT, van der Pas MH, Hulleman M, van de Glind EM, van Munster BC, Tijssen JG, Tan HL, van Delden JJ, Koster RW. Comorbidity and favorable neurologic outcome after out-of-hospital cardiac arrest in
patients of 70 years and older. Resuscitation. 2015 Sep;94:33-9. doi: 10.1016/j.resuscitation.2015.06.017. Epub 2015 Jun 25. PMID: 26116780.
and
Dutch Heart Foundation
https://hartstichting-hartstichting-portal-p01.s3.eu-central-1.amazonaws.com/s3fs-public/2022-11/boek-hartstichting-reanimatie-cijfersboek-2016.pdf?VersionId=3ryeDwunauHIgBzBR9Tcszc8T439M3oC

Overview and insight

Neurologist Dr. G. Roks made the overview below about the duration of the oxygen deficiency and the damage to both the brainstem and cerebral cortex. He also made a Powerpoint presentation (in Dutch) about Postanoxic encephalopathy. Available for download below.

Postanoxische Encephalopathie Dr Roks Ppt
PowerPoint – 2,2 MB 58 downloads

A neuropsychological evaluation and/or cognitive rehabilitation is recommended. Visually invisible damage is also examined.

 

The document below provides information in English. 

Brain damage after cardiac arrest.pdf
PDF – 681,9 KB

Resources

Hersenletsel-uitleg.nl

Argent, D. E., & Cope, D. H. (1956, 17 maart). Cerebral hypoxia: aetiology and treatment. British Medical Journal, pp. 593–598. Consulted from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1979171/

Beesems SG, Blom MT, van der Pas MH, Hulleman M, van de Glind EM, van Munster BC, Tijssen JG, Tan HL, van Delden JJ, Koster RW. Comorbidity and favorable neurologic outcome after out-of-hospital cardiacarrest in patients of 70 years and older. Resuscitation. 2015 Sep;94:33-9. doi: 10.1016/j.resuscitation.2015.06.017. Epub 2015 Jun 25. PMID: 26116780.

Berek, K., Jeschow, M., & Aichner, F. (1997). The Prognostication of Cerebral Hypoxia after Out-of-Hospital Cardiac Arrest in Adults. European Neurology, 37(3), 135–145. https://doi.org/10.1159/000117426

Cronberg T, Greer DM, Lilja G, Moulaert V, Swindell P, Rossetti AO. Brain injury after cardiac arrest: from prognostication of comatose patients to rehabilitation. Lancet Neurol. 2020;19:611–622De Nederlandse Hartstichting. (z.d.). Oplossingen voor een sterk hart | Hartstichting. Consulted on 7 juni 2013, van https://www.hartstichting.nl/

Fischer M, Bockhorst K, Hoehn-Berlage M, Schmitz B, Hossmann KA. Imaging of the apparent diffusion coefficient for the evaluation of cerebral metabolic recovery after cardiac arrest. Magn ResonImaging. 1995;13:781–790.Geocadin RG, Callaway CW, Fink EL, Golan E, Greer DM, Ko NU, Lang E, Licht DJ, Marino BS, McNair ND, Peberdy MA, Perman SM, Sims DB, Soar J, Sandroni C, American HeartAssociation Emergency Cardiovascular Care C Standards for studies of neurological prognostication in comatose survivors of cardiac arrest: a scientific statement from the American Heart Association. Circulation.2019;140:e517–e542.

Eyskens, E., Feenstra, L., Meinders, A. E., Vandenbroucke, J. P., & Van Weel, C. (1997). Codex Medicus (10e ed.). Maarssen, Nederland: Elsevier Gezondheidszorg.

Ik wil nooit beroemd worden [Film]. (2010, 29 juli). Consulted on 7 juni 2013, van https://www.2doc.nl/documentaires/series/hollanddoc/2007/Ik-wil-nooit-beroemd-worden.html

Koenig MA. Brain resuscitation and prognosis after cardiac arrest. Crit Care Clin. 2014 Oct;30(4):765-83. doi: 10.1016/j.ccc.2014.06.007. Epub 2014 Jul 30. PMID: 25257740.Kuks, J. B. M., Snoek, J. W., Oosterhuis, H. G. J. H., & Fock, J. M. (2003). Klinische neurologie (15e ed.). Houten, Nederland: Bohn Stafleu van Loghum.

Madl, C., & Holzer, M. (2004). Brain function after resuscitation from cardiac arrest. Current Opinion in Critical Care, 10(3), 213–217. https://doi.org/10.1097/01.ccx.0000127542.32890.faNg YY, Wah W, Liu N, Zhou SA, Ho AF, Pek PP, Shin SD, Tanaka H, Khunkhlai N, Lin CH, Wong KD, Cai WW, Ong ME; PAROS Clinical Research Network. Associations between gender and cardiac arrest outcomes inPan-Asian out-of-hospital cardiac arrest patients. Resuscitation 2016;102:116–121 Rossen R, Kabat H, Anderson JP. Acute arrest of cerebral circulation in man. Arch Neurol Psychiatr. 1943;50:510–528.

Palm, J. (2012). Omgaan met Hersenletsel. Assen, Nederland: Van Gorcum.

Roks, G. (2012, 7 november). Postencefalitische encephalopathie,neurologische aspecten. Consulted on 13 juni 2013, van https://www.slideserve.com/barb/postanoxische-encephalopathie-neurologische-aspecten Sandroni C, Cronberg T, Sekhon M. Brain injury after cardiac arrest: pathophysiology, treatment, and prognosis. Intensive Care Med. 2021 Dec;47(12):1393-1414. doi: 10.1007/s00134-021-06548-2. Epub 2021 Oct 27. PMID: 34705079; PMCID: PMC8548866.

Verenso, NHG, & V&VN. (2013, 4 april). Reanimatie - Verenso. Consulted on 7 juni 2013, van https://www.verenso.nl/kwaliteit-en-richtlijnen/richtlijnendatabase/reanimatie-1

 www.bosk.nl/cerebrale-parese/wat-is-cp/oorzaken/. (z.d.). Consulted from https://www.bosk.nl/cerebrale-parese/wat-is-cp/oorzaken/

 Wachelder EM, Moulaert VR, van Heugten C, Verbunt JA, Bekkers SC, Wade DT. Life after survival: long-term daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation. 2009;80:517– 522.

https://www.quartztransmuraal.nl/QuartzSite/Protocollen/Regio%20Helmond/Folder%20DNR%20def.pdf

Images are from Anatomography maintained by Life Science Databases(LSDB)