Nav: Home

Update on determination of death: Experts call for international consensus

June 02, 2013

The criteria used to diagnose both circulatory and brain death in a patient are subject to variability and as such can be controversial. Anaesthesiologists play an important role in procedures related to the determination of death, so should have specific knowledge about medical, ethical and legal criteria of brain death definition. Experts will call for international consensus in a presentation at Euroanaesthesia 2013, the annual congress of the European Society of Anaesthesiology (ESA).

"Before the technological advances of the last century, death was diagnosed by presence of coma, apnoea, and lack of a pulse. The failure of the cardiovascular or respiratory systems inevitably led to a person dying," says presenter Ricard Valero, Senior Consultant Anaesthesiologist at the Hospital Clínic de Barcelona, and Associate Professor of Anaesthesiology at University of Barcelona, Spain.

However, the establishment of the criteria determining neurological (brain) death during the 20th century represented a significant change regarding the traditional method to define death and still is a challenge from the ethical and scientific point of view. "For this diagnosis, it is essential to demonstrate irreversible coma, absence of response to stimuli and absence of brainstem reflexes (including the capacity to breathe), once the situations that could interfere with the diagnosis have been discarded," says Valero. "However, several studies have demonstrated that there is no global consensus on what are the detailed diagnostic criteria for this determination in clinical practice, such as the number of physicians needed to agree on the diagnosis, how many and which reflexes need to be examined, length of observation periods, and use of additional tests to confirm death."

"Biological death is not an event, but a process," concludes Valero. "Anaesthesiologists participate in the decision-making around this process, and we have to establish clear and unequivocal criteria for the diagnosis of death, knowing the emerging ethical implications."

Valero says that, while every doctor should be involved in the debate in general terms, that it is most relevant to anaesthesiologists, intensive care doctors, neurologists and neurosurgeons, since they are the specialties most commonly involved in determining death in the clinical setting.

In another part of the session Dr Alex Manara (Consultant in Anaesthesia and Intensive Care Medicine & Regional Clinical Lead in Organ Donation for the UK South West Region, Frenchay Hospital, Bristol, UK) will discuss the circulatory criteria to confirm death and argue that with 600,000 deaths in the UK each year and 56 million deaths worldwide, "we should know all there is to know about death." Yet unlike brain death there has been virtually no guidance until recently to standardise the circulatory-respiratory criteria.

He will say "there needs to be consensus around a practical and concrete definition of death that describes the state of human death based on measurable and observable biomedical standards". He will call for "a research agenda to address outstanding knowledge gaps in this complex field."

Dr Manara will discuss an operational definition of death being proposed by an expert forum organised by the Canadian Blood Services in collaboration with the World Health Organization. This states death occurs when there is permanent loss of capacity for consciousness and loss of all brainstem functions. This may result from permanent cessation of circulation and/or catastrophic brain injury--in this context permanent means a loss of function that cannot resume spontaneously or be restored through intervention.

Problems arise because the point of absolute "irreversibility" of loss of the circulation is vague and will vary from person to person as well as depend on the medical equipment and interventions available. The point of "permanence" however is better defined and is how death is determined correctly in everyday medical practice. A very few cases have been reported of people having suffered a cardiac arrest before being declared dead but in whom the circulation was spontaneously restored several minutes later and some went on to recover. Dr Manara will argue that this possibility can be eliminated by the continuous observation of the patient for a minimum of 5 minutes to confirm absence of the circulation before declaring death. This should become the minimum standard for clinical declaration of death by circulatory criteria and will maintain professional and public confidence in the diagnosis of death, both after terminating CPR and in the context of organ donation after the circulatory determination of death.

Dr Manara concludes "The work begun by WHO in this sensitive and complex area needs to continue and to be supported globally".
-end-


ESA (European Society of Anaesthesiology)

Related Brain Articles:

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.
Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.
BRAIN Initiative tool may transform how scientists study brain structure and function
Researchers have developed a high-tech support system that can keep a large mammalian brain from rapidly decomposing in the hours after death, enabling study of certain molecular and cellular functions.
Wiring diagram of the brain provides a clearer picture of brain scan data
In a study published today in the journal BRAIN, neuroscientists led by Michael D.
Blue Brain Project releases first-ever digital 3D brain cell atlas
The Blue Brain Cell Atlas is like ''going from hand-drawn maps to Google Earth'' -- providing previously unavailable information on major cell types, numbers and positions in all 737 brain regions.
Landmark study reveals no benefit to costly and risky brain cooling after brain injury
A landmark study, led by Monash University researchers, has definitively found that the practice of cooling the body and brain in patients who have recently received a severe traumatic brain injury, has no impact on the patient's long-term outcome.
Brain cells called astrocytes have unexpected role in brain 'plasticity'
Researchers from the Salk Institute have shown that astrocytes -- long-overlooked supportive cells in the brain -- help to enable the brain's plasticity, a new role for astrocytes that was not previously known.
Largest brain study of 62,454 scans identifies drivers of brain aging
In the largest known brain imaging study, scientists from Amen Clinics (Costa Mesa, CA), Google, John's Hopkins University, University of California, Los Angeles and the University of California, San Francisco evaluated 62,454 brain SPECT (single photon emission computed tomography) scans of more than 30,000 individuals from 9 months old to 105 years of age to investigate factors that accelerate brain aging.
Is whole-brain radiation still best for brain metastases from small-cell lung cancer?
University of Colorado Cancer Center study compares outcomes of 5,752 small-cell lung cancer patients who received whole-brain radiation therapy (WBRT) with those of 200 patients who received stereotactic radiosurgery (SRS), finding that the median overall survival was actually longer with SRS (10.8 months with SRS versus 7.1 months with WBRT).
Atlas of brain blood vessels provides fresh clues to brain diseases
Even though diseases of the brain vasculature are some of the most common causes of death in the West, knowledge of these blood vessels is limited.
More Brain News and Brain Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.