Was den Menschen zum Menschen macht

Irreversible Loss of Brain Function

12 Min. Lesezeit

🇩🇪 Deutsche Version: Irreversibler Hirnfunktionsausfall (Hirntod)

The irreversible loss of all brain functions — colloquially called “brain death” — is not to be equated with certain death. The affected person lives, insofar as he is kept alive by mechanical life support (in particular a heart-lung machine). Personhood and ontological dignity remain fully intact.

The decisive point is the distinction between prote energeia and deutera energeia: affected is solely the deutera energeia — the actual exercise of spiritual faculties such as cognition, self-consciousness, and will. The prote energeia — the first actuality of personhood, the fundamental spiritual being — remains untouched as long as the person lives.

The principle agere sequitur esse states: action follows being, not the reverse. Whoever ties personhood to the exercise of brain functions holds an empirical-functionalist concept of person in the line of Locke, Singer, and Parfit, and confuses personhood with person-behavior — a form of oblivion of the person. Opposed to this stands the substance-ontological concept of person as represented by Thomas, Spaemann, and Hengstenberg.

The parallel to severe dementia is instructive: in both cases the deutera energeia is impaired, in both cases the person remains a person. Spaemann puts it: “Someone who was a person has not ceased to be a person.” The objection from diachronic identity — which ties the identity of the person to continuous streams of consciousness — does not hold here: the uniqueness of the person lies in its being, not in its memory.

Ontological classification

Superordinate concepts: state, process

Ontological relations:

Chapter assignment: Chapter 4: What Is Human Personhood? (German)

Three clinical conceptions of brain death

The term “brain death” is not uniformly defined in the international medical-legal discourse. One distinguishes three competing conceptions that hold in different jurisdictions:

Whole-brain death — failure of the functions of all brain structures (cerebrum, cerebellum, brainstem). This is the criterion in force in Germany, Austria, the USA, and Switzerland. The revised commentary on the Uniform Determination of Death Act (USA, 2021–2023) continues to work on the question whether “all functions” means this literally or only “clinically relevant functions,” since the hypothalamic-pituitary axis can demonstrably keep working in formally “brain-dead” bodies.

Brainstem death — failure of the brainstem functions alone. This is the criterion valid in the United Kingdom and is based on the assumption that the brainstem is the integrative relay station whose failure entails the failure of the whole. Bexten’s dissertation does not take up this criterion as sufficient, because cortical activity can persist in pure brainstem failure.

Cerebral death (higher-brain death) — failure of the cortical functions alone with the brainstem preserved. No legal system recognizes this as a definition of death. Proponents (Veatch, Lizza) hold it within the framework of an empirical-functionalist concept of consciousness; from the standpoint of the ontology represented here, the position is incompatible with agere sequitur esse, because it again binds personhood to cognitive exercise and thereby falls prey to the exclusion objection.

In all three variants the same holds for personal ontology: as long as the ensouled body — the body-soul unity in the sense of the Thomistic forma corporis — exists, the person remains a person. Ontologically, every loss of brain function concerns the deutera energeia, not the prote energeia — a difference that can be thought only against the background of the substance category of classical substance ontology.

Certain death — a distinction

Certain death is the irreversible loss of bodily integration itself: the disintegration of the organism as a whole, which can no longer be maintained by mechanical substitution. It is ontologically to be distinguished from irreversible loss of brain function — the two states mutually exclude each other.

This distinction has practical significance: the Dead Donor Rule of transplantation medicine requires that donors be dead before organs are removed. If brain death and certain death are not the same, then — ontologically speaking — the removal of organs from a brain-dead donor is not removal from a corpse, but from a living human being whose bodily integration is supported by machines. The bioethical assessment thereby comes into conflict with the personalist norm, which excludes the instrumentalization of the person.

Scholarly discourse: five positions

The brain-death criterion has, since the Harvard Ad Hoc Committee definition (1968), been the object of international philosophical, medical, and theological critique. Five positions shape the discourse; they converge in the basic ontological insight that brain death and certain death are not identical, but they ground this differently.

Alan Shewmon — somatic integration. The American pediatric neurologist, originally a proponent of the whole-brain-death criterion, documented in a case series (among others Chronic “Brain Death”, 1998) brain-dead bodies that continued to exist for months and in individual cases years through mechanical ventilation: wound healing, immune defense, growth, in one case a pregnancy carried to term. The brainstem thesis — that the brainstem is the necessary integrative relay station — is thereby empirically refuted. Somatic integration occurs in a distributed, not a centralized, manner. Shewmon’s argument is not a theological one, but a physiological one — and it strikes the criterion on its own standard.

Hans Jonas — the simulacrum. In “Against the Stream: Comments on the Definition and Redefinition of Death” (1974), Jonas warns against redefining death in order to facilitate organ harvesting. The brain-death definition creates a “simulacrum of life”: a body we declare outwardly to be dead but which shows all visible signs of life. Jonas demands the precautionary principle in dubio pro vita — in uncertainty, the human being is to be treated as living, not as dead.

Benedict XVI — ecclesial precautionary principle. In his address to the congress “A Gift for Life” (November 2008), the Pope affirmed that the Church does not definitively confirm the brain-death criterion. Organ removal is permissible only if a donor is dead with certain assurance — and this assurance is not given in brain death. The position remains deliberately open between recognition and rejection, but rejects the equation “brain death = death” as insufficiently grounded.

Federal Medical Association — terminological refinement (Fourth Amendment 2015, Fifth Amendment 2022). The Federal Medical Association replaced the German term “brain death” (Hirntod) in its guidelines with “irreversible loss of brain function” (irreversibler Hirnfunktionsausfall) — the change of wording was made with the Fourth Amendment in 2015 and was retained in the Fifth Amendment in 2022. The terminological correction takes account of the insight that what is at issue is a loss of function, not necessarily the death of the person. It changes nothing in the legal situation but makes the imprecision of the older terminology visible.

UDDA revision 2021–2023 — an open conceptual question. The Uniform Law Commission in the USA is working on a revision of the Uniform Determination of Death Act. The point of contention is whether the loss of hypothalamic-pituitary control (which frequently persists in brain-dead bodies) must be counted as a loss of function or is exempted from the definition. The process shows: even in the legal core area of the brain-death definition, the concept is not settled.

Consequences

From the insight “brain death is not certain death” three practical consequences follow.

First: the dignity of the human being with irreversible loss of brain function remains undiminished — as ontological dignity, not as functional dignity. He is not a “former person” and not a “mere organism,” but a living person whose exercise of function is lost. The personalist norm (Wojtyła) forbids using him as a mere means.

Second: organ removal from a brain-dead donor is ontologically not removal from a dead person. The ethical assessment must therefore go beyond the mere legal fiction and critically interrogate the Dead Donor Rule — even if this would considerably change current transplantation practice.

Third: the precautionary principle in uncertainty is appropriate. Where the identity of brain death and certain death is not established, the human being is to be treated as living, and the burden of proof lies with the one who declares him dead.

See also

Concepts — end of life and medicine

Concepts — organ donation and precaution (parallel discussion)

Concepts — ontological foundations

Concepts — dignity and ethics

Concepts — objections

Thinkers — ontological-substantial line

Thinkers — functionalist counterposition

Sources: Generated by querying the Personhood ontology (cf. Bexten 2017, pp. 195 ff., 293 ff., on personhood and brain death).

Further sources for the discourse:

  • Ad Hoc Committee of the Harvard Medical School (1968): A Definition of Irreversible Coma. JAMA 205(6), pp. 337–340.
  • Shewmon, D. Alan (1998): Chronic “Brain Death”: Meta-Analysis and Conceptual Consequences. Neurology 51(6), pp. 1538–1545.
  • Jonas, Hans (1974): Against the Stream: Comments on the Definition and Redefinition of Death, in: Philosophical Essays: From Ancient Creed to Technological Man. Englewood Cliffs: Prentice-Hall.
  • Benedict XVI (2008): Address to the Participants of the Congress “A Gift for Life. Considerations on Organ Donation”. Vatican, 7 November 2008.
  • Bundesärztekammer (2015): Richtlinie gemäß § 16 Abs. 1 S. 1 Nr. 1 TPG für die Regeln zur Feststellung des Todes … und die Verfahrensregeln zur Feststellung des endgültigen, nicht behebbaren Ausfalls der Gesamtfunktion des Großhirns, des Kleinhirns und des Hirnstamms. Fourth Amendment. Deutsches Ärzteblatt 112(14), A-572–A-580.
  • Bundesärztekammer (2022): Richtlinie zur Feststellung des irreversiblen Hirnfunktionsausfalls. Fifth Amendment.
  • Uniform Law Commission (2021–2023): Revision of the Uniform Determination of Death Act. Drafting Committee; paused in September 2023.
  • Veatch, Robert M. / Ross, Lainie F. (2016): Defining Death: The Case for Choice. Washington: Georgetown University Press.

Diagnostic determination

The determination of irreversible loss of brain function proceeds via clinical and instrument-based irreversibility diagnostic procedures. The clinical procedures include the apnea test and the testing of the brainstem reflexes; the instrument-based ones include the EEG flatline, transcranial Doppler sonography, cerebral angiography, and perfusion scintigraphy.

In Germany, the Federal Medical Association guideline on the determination of irreversible loss of brain function (5th Amendment 2022) prescribes observation intervals of 12 hours (primarily supratentorial injury) or 72 hours (secondary hypoxic injury) between the clinical examinations.

The empirical crisis of the concept shows itself in residual hypothalamic function: in a significant proportion of patients diagnosed as clinically brain-dead, ADH secretion and osmoregulation persist — the UDDA requirement “irreversible cessation of all functions of the entire brain” is thereby empirically not fulfilled.

What remains decisive from the standpoint of substance ontology is: even a reliable functional diagnosis is a medically diagnosed irreversibility, not the ontological irreversibility of the separation of body and spiritual substance.

Tension of meaning in the class name

The word component “irreversible” in the class name employs the weaker medically diagnosed irreversibility — an inductive, falsification-open inference from observation period and causal theory — not the ontological irreversibility (Hartmann, Ethik 1926; Möglichkeit und Wirklichkeit 1938: a constitutive mode of the actual).

Whoever reads “irreversible” here as an ontological statement commits a modal fallacy: he identifies the diagnostic threshold (mode of the possible) with the mode of the actual. Residual hypothalamic function (Nair-Collins, Northrup, Olcese, J Intensive Care Med 31, 2016, pp. 41–50; Nair-Collins, Miller, J Intensive Care Med 37, 2022, pp. 153–155) shows empirically that even the diagnostic threshold is not fully met in up to 50 percent of cases.

The historical terminological regulation of the Federal Medical Association 2015 (4th Amendment of the brain-death guideline, retained in the 5th Amendment 2022) — “brain death” → “irreversible loss of brain function” — expressly sought to sharpen the difference from certain death. But it replaced one misleading word with a second: the ontological weight that “irreversible” suggests, the term does not carry in the concrete context of application. It is precisely here that the precautionary principle (Benedict XVI, Address to the International Congress on Organ Donation, Rome 2008) sets in normatively: where certainty is not attained, the stricter interpretation holds.

Sources for this section

Graphansicht

Backlinks