see also:

• the deceased patient in the ED
• end of life care
• how to verify death
• verification of brain death in the ventilated patient
• reportable and reviewable deaths - deaths which MUST be reported to the Coroner
• how to complete a death certificate for cause of death
• preparing for the worst - making life easier for your loved ones if you become critically ill or die
• on the death of your loved one - estate issues and more

• once upon a time death was a relatively simple concept - once your heart stopped you were “dead”
• in other words, empirically, it was noted that it was very rare for a person to come to life once their heart and pulse had ceased - although given the rather insensitive methods for detecting cardiac activity and pulses without stethoscopes, many may have indeed been falsely regarded as having died and some would “come back to life”, at least temporarily, such as those with severe hypovolaemic shock from blood loss or dehydration.
• this concept of death has evolved into what we now regard as “circulatory death” - irreversible cessation of the circulation of blood in a person's body - see how to verify death.
• then along came CPR, defibrillation, intubation and positive pressure ventilation, and it was possible that some of these people with good evidence of “circulatory death” could have their circulation and ventilation restored
  • many of these could not have their circulation maintained and resuscitation attempts were regarded as futile and terminated, thus they “died”
  • some of these regained consciousness and were able to be removed from all circulatory and ventilatory support and were able to be discharged from hospital, albeit with variable neurologic deficits largely dependent upon the degree of initial hypoxia the brain was exposed to and the secondary damage from further insults whilst being ventilated.
  • some were able to be “kept alive” on a ventilator for many days but failed to regain consciousness which created a dilemma as to how long they should be kept on a ventilator.
    • for this group, a new definition of death was created in the 1980's - verification of brain death in the ventilated patient, and this has been an important factor in feasability of organ donation in these patients.
• death is a process not always a single timed event
  • it is recognised that just because the circulation ceases, the body is not instantly dead, despite the desire of legal definitions to make death an “event” rather than a “process”, but various cells of the body which are deprived of oxygen as a result of this do START to die at variable rates - many cell types may actually be alive for hours, particularly if they do not have high oxygen demands such as when they are cooled down.
• to complicate the picture further, new medical resuscitation methods, particularly, hypothermic cerebral protection and ECMO, have meant that those with choking / respiratory arrest / cardiac arrest / BLS / ALS / CPR could potentially be placed in a prolonged state of both circulatory and ventilatory support whilst hopefully protecting the organs from damage while the underlying cause can be addressed.
• finally, there is the concept of information-theoretic death which is the destruction of the information within a human brain such as a person's memories, personality, etc. The cryonics industry attempts to preserve this aspect of the brain in the hope that future technology can access it or restore it, although it is extremely doubtful that freezing the brain will address this. This is very different from the proven hypothermic cerebral protection used in ED's and ICU's in patients post-arrest.

• resuscitation of a patient with cessation of circulation is generally NOT attempted if either:
  • there is an advanced directive from the patient or their family that resuscitation is not wanted - the so-called NFR order
  • it is obvious that all attempts would be futile (eg. decapitation)
  • it is obvious that this is a terminal event for a patient and attempted resuscitation would only prolong the inevitable death and the suffering (eg. palliative care cancer patient)
  • the patient has not had a circulation for a prolonged length of time and the period of no or poor quality CPR is more than an arbitrary 10 minutes, and was unlikely to have been hypothermic at the time circulation ceased, and meets verification of death criteria

• resuscitation of a patient with cessation of circulation is generally ceased if either:
  • it becomes evident one of the above conditions that resuscitation should not have been commenced is present
  • the circulation cannot be restored after a reasonable duration of CPR (usually about 20 minutes), and there is no readily reversible untreated underlying cause evident (eg. tension pneumothorax, digoxin toxicity), and there is no ready access to ECMO or the person would not benefit from ECMO