Comment: Between life and death

Di Liang, University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Road, Cambridge, CB2 0SP

A recent BBC documentary, ‘Between life and death’ followed the moving stories of three patients at the Addenbrooke’s Neurological Critical Care Unit, a leading centre of its kind in the world (BBC1, 2010). These patients were all involved in road traffic accidents that left them deeply brain damaged and dependent on life support machines.

In particular, this had implications on their capacity to consent to further medical decisions. What followed was an intimate portrayal of how staff, relatives and sometimes the patients themselves influenced decisions on whether to withdraw life sustaining treatments or wait and give potential recovery a second chance.

The programme presented two significant ethical issues, the modern medical definition of death and the capacity to consent. Although the two central ideas included in the documentary were intuitive and sufficient for the general public, medical professionals must consider the issue more deeply in order to make clinical decisions in such situations.

In the past, a major failure in one part of the body usually led to deterioration in the functioning of others. Patients whose heart or lung functions stopped progressed rapidly to hypoxic-ischaemic damage of other critical tissues, causing unequivocal death within a short amount of time. Accordingly death has always been viewed as a singular event (Morison , 2003), signified by the absence of heart beat, breathing, and pupillary reactions to light.

The last half of the 20th century has seen enormous advances in medical technology, one aspect of which is the ability to maintain or almost indefinitely replace the functions of the cardio-vascular and respiratory systems. However this has not been matched in the field of neurology, creating a situation where we are now able to keep most subsystems of the body alive while the brain remains beyond repair. This divergence has challenged not only clinicians, but philosophers, religions, and the general public to redefine the division between life and death. The concept of ‘brain death’ was introduced to provide an ethical and practical framework on which clinicians may make their decisions (Committee of the Harvard Medical School to Examine the Definition of Brain Death, 1968). However a unifying definition of ‘brain death’ still does not exist, with opinions divided into three main camps, the ‘whole brain formulation’, ‘higher brain formulation’ and the ‘brain stem formulation’. (Bernat , 1994)

The ‘whole brain formulation’ proposes that brain function is an integration of different constituents such as the cortices, diencephalon, brain stem, cerebellum, and that the whole is greater than the sum of its parts. The brain as a whole and the integration of functions must be lost before one can assume brain death. This definition has gained wide acceptance in North America and some European countries (President’s Commission , 1981).

The ‘higher brain formulation’ assumes brain death as having occurred when there is permanent loss of qualities considered essential to the nature of a human being. Proponents of this theory would define brain death as death of the anatomical neocortex. This formulation is attractive practically in that it immediately solves the problem of the persistent vegetative state, since the patients are dead. However there are some serious flaws with this argument. For example, how much cortical function must be lost before we define death? What about patients in advanced stages of dementia, who have perhaps lost some of the qualities considered essential to a human being? Furthermore, the higher brain formulation would require a radical redefinition of death; at no point in history, or any culture have patients who breathe spontaneously been declared dead. This poses considerable practical problems regarding burial of such patients, would they be buried with spontaneous breathing and circulation or would such functions be actively terminated? Because of these significant flaws this formulation has not been adopted around the world. (Bernat , 1994)

The UK is one of the few proponents of the ‘brain stem formulation’ (Conference of Medical Royal Colleges , 1979). This argument came about mainly due to the work of Christopher Pallis (Pallis , 1983). He observed that most bedside tests for brain death, such as pupillary reflexes, cranial nerve functions and apnoea rely on brain stem function. Additionally, the brain stem contains the structures necessary for the maintenance of consciousness and spontaneous respiration, as well as the major pathways for motor and sensory signals between the brain and the rest of the body. The ‘brain stem formulation’ is an attractive one and is relatively easy to apply clinically. However opponents have identified a serious theoretical flaw in this argument. Although highly unlikely, there exists the possibility of a patient retaining consciousness despite having lost all other evidence of brain stem function, thus rendering it impossible for the consciousness to manifest itself, a so-called ‘total locked in syndrome’. (Bauer, 1979)

It is important to note that some countries such as Japan and Denmark have rejected ‘brain death’ as equal to ‘death’ in the traditional sense. These counties continue to apply the traditional circulatory formulations of death characterised by the absence of heartbeats and breathing (Danish Council of Ethics. 1988 and Kimura , 1991)

The second ethical issue raised by the programme involved the withdrawal of life sustaining treatments where the patients lacked the capacity to consent for themselves. The current ‘Mental Capacity Act’ states that no one can be labelled as ‘incapable’ based on any particular medical condition or diagnosis (Mental Capacity Act ,2005). Each test of capacity must be decision specific and take into account the context of the situation. Incapacity should be considered when patients are unable to do any one or more of the following:

1) the ability to understand the information
2) the ability to retain the information
3) the ability to weigh up the different choices as part of a decision making process
4) the ability to communicate their decision (Mental Capacity Act ,2005).

If the patient is assessed as lacking capacity, the legal obligation is to act in their best interests through management that is least restrictive to their basic rights and freedoms (Mental Capacity Act ,2005). If the court is asked to determine matters of best interests, it must assess whether the proposed management plan is in accordance with a responsible body of medical opinion (General Medical Council, 2010), as well as the broader ethical, social, moral & welfare issues (Re, 2000). When considering the ethical aspects of best interests, one possible approach is to balance the four principles of non-maleficence, beneficence, autonomy and justice (Beauchamp, 2001).

Aggressive life sustaining treatments such as intubation, feeding tubes and catheters are highly invasive to the patient. Clinicians must consider the principle of non-maleficence and the justification for continuation of such treatments, particularly in situations where the chances of recovery are small. Beneficence is often ambiguous where the decision is between death and continuation of life with significant neurological deficits. Respect for autonomy is a more powerful ethical principle in such cases. This can be achieved through substituted judgement where relatives and friends may help the clinicians to establish what the patient themselves would have wanted had they retained capacity. Finally justice is also relevant when considered in the setting of limited healthcare resources. The allocation and diversion of resources for the treatment of patients whose likelihood of recovery is so small as to be negligible may be argued by some to be unethical due to the concept of medical futility (Bernat , 1994).

The ethical issues involved in brain death and related situations are some of the most complex and enduring in modern medicine. Future developments in the definition of brain death may come about due to advances in imaging technology, the ability to accurately measure brain activity and a greater understanding of the brain. When considering such issues as medical professionals, we must be aware of the reciprocal influences between our medico-scientific understanding of life and death and the cultural, philosophical, and religious attitudes of the societies in which we live.

REFERENCES

BBC1. 2010 ‘Between Life and Death’, BBC Documentary. BBC1. 13/7/2010.

Morison RS. 1973. Death: process or event? Science; 173:694-698

Committee of the Harvard Medical School. 1968. A definition of irreversible coma. Report of the Ad Hoc Committee of the Harvard Medical School to Examine the Definition of Brain Death, JAMA; 205:337-340.

Bernat JL. 1994. Ethical Issues in Neurology. Clinical Neurology, Philadelphia: JB Lippincott.

President’s Commission for the Study of Ethical Problems in Medicine and Biomedical and Behavioural Research. 1981. Defining death. Medical, Ethical and Legal Issues in the Determination of Death.

Conference of Medical Royal Colleges and their Faculties in the UK. 1979. ‘Diagnosis of brain death’ BMJ. 1:322.

Pallis C. 1993. ‘ABC of Brainstem Death’. London: British Medical Journal Publishers.

Bauer, G. et al. 1991. Varieties of the locked-in syndrome. Journal of Neurology 211 (2): 77–91.

Danish Council of Ethics. 1998. Death Criteria: A Report.

Kimura R. 1991. Japan’s dilemma with the definition of death. Kennedy Institute of Ethics Journal. 1:123-131.

Mental Capacity Act 2005. London: The Stationery Office.

End of Life Care – Guidance for Doctors, General Medical Council, 2010

Re S (adult patient: sterilisation) 2000. 26 May (CA)

Beauchamp, T. L., and Childress, J. F. 2001.Principles of Biomedical Ethics. (5th ed). Oxford: Oxford University Press.