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Life-sustaining treatment has been withdrawn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
