top of page

Diagnosing death

The irreversible loss of capacity to breath spontaneously

The irreversible loss of consciousness

Death in the UK can be diagnosed by three methods all of which are defined by these two statements 

Diagnosis of death in the UK is governed by guidance from the Academy of Medical Royal Colleges

Somatic - where death is obvious

  • Purification

  • Decapitation

  • Traumatic hemi-corpectomy

  • Incineration

  • Rigor-mortis

Circulatory - where the heart has ceased functioning

One of these pre-conditions must be met:

  • Life-sustaining treatment has been withdrawn

  • Resuscitation will not be attempted

  • Resuscitation has been attempted and failed

Diagnosis is made by:

  • 5 minute period of observation for cardiorespiratory arrest

followed by​

  • Cranial nerve testing

    • No response to supra-orbital pressure​

    • Absent pupillary light reflex

    • Absent corneal reflex


Neurological - where the brain has ceased functioning

Both of these pre-conditions must be met:

  • Patient is in an irreversible coma of known aetiology

  • All potentially reversible causes of coma have been eliminated

Diagnosis is made by:​

  • Cranial nerve testing

    • No response to supra-orbital pressure​

    • Absent pupillary light reflex

    • Absent corneal reflex

    • Absent occulogyric relfex

    • Absent gag reflex

    • Absent cough reflex


followed by​​ a 5 minute period of observation for respiratory arrest

Brainstem death testing

Diagnosis of death by neurological criteria

The concept of brain death evolved as a consequence  of intensive care medicine. With the advent of mechanical ventilation, augmented by physiological support of the circulation a new cohort of patients emerged; those with devastating neurological injury rendering them unable to regain consciousness who were entirely dependent on mechanical ventilation without which they would certainly die. This was termed "coma depasse" (brain dead).

In 1968 simultaneous publications by an ad hoc committee of the Harvard Medical school and World Medical Association provided a definition of brain death which was adopted into clinical practice. It took until 1976 for the Conference of the Medical Colleges and their faculties to formalise this into "brain stem death". Since then the practice of brain stem death testing has changed little and remains essentially a clinical bedside test.

Conduct of brain stem death testing

The conduct of brainstem death testing is described in the AoMRC document "A Code of Practice for the Diagnosis and Confirmation of Death"

The code of conduct has been translated into a more user-friendly document by a FICM/ICS group

Brainstem death testing can only be conducted by:

  • Two doctors

  • Both must be fully registered for a minimum of 5 years

  • One must be a consultant

  • Both must be fully competent with the conduct of testing

Pre-conditions for testing
Testing happens twice
Each doctor should conduct one set of tests and observe the other
There is no specified timescale between test
bottom of page