The diagnosis of death is mostly straightforward; the medical practitioner looks for somatic, cardio-respiratory and neurological features. Clearly, someone with rigor mortis is dead. Someone with no spontaneous breathing, no heartbeat and no pulse, and whose pupils are fixed and dilated presents the classical features of death. This is usually enough to diagnose most cases of ‘death’, though as the Victorians had a morbid dread of being buried alive, the tradition of requesting a surgeon to open an artery persisted into my youth.
With artificial ventilation (‘life support’) came a new challenge. A patient with, say, a serious head injury could be ventilated artificially, and this would keep the heart beating. But was this person ‘alive’ or ‘dead’? The French introduced the term coma dépassé meaning ‘a state beyond coma’. From this developed the concept of ‘brain death’ or ‘brain stem death’. The brain stem lies at the base of the brain and contains the centres for ‘vegetative functions’, controlling respiration, heartbeat and the pupils amongst others. Above the brain stem are the cerebral hemispheres, the higher centres of the ‘mind’, of emotions, of language, of visual processing etc.
It was recognised that without a live brainstem to drive breathing and the heartbeat, the patient would die. This concept is the basis of the diagnosis of ‘brain stem death’ in the UK. A rather different approach to ‘brain death’ is used in other parts of the world. Note this this is not coma vigile or the ‘vegetative’ state, where the brain stem is intact, but the higher centres are partially or completely damaged.
Somewhat later than the recognition of coma dépassé came organ transplantation which worked best when the tissues to be transplanted were ‘alive’ even if the patient was brain dead, for death is not an instantaneous event, rather it is a process. Tissues most susceptible to lack of oxygen, such as the brain, die first; more resistant tissues take longer. In practical terms, the team looking after a patient who has suffered a catastrophic brain insult will ask two senior but entirely independent consultants for their opinion as to whether the patient is brain dead. These two perform tests of brain stem function; and then disconnect the patient from the ventilator to see if there is any spontaneous breathing. The tests are repeated. Even when disconnected from the ventilator (and not breathing) the patient will still have a heartbeat. The presence of a heartbeat is not sufficient in these circumstances to say that the patient is ‘alive’. If the patient is declared to be brain dead, and is to be an organ donor, then, and only then, will the transplant team take over; they play no part in the diagnosis of death. Remember, it is possible to be dead yet still have a heartbeat.Today, the ultimate diagnosis of death lies with the brain and the brainstem; there may be a heartbeat for several days after the brain stem has been declared dead.
Rather strangely, the law in N Ireland is largely silent when it comes to the definition of a foetus. I understand that, legally, a pregnancy is where the embryo implants into the uterus, so that implantation elsewhere, such as in the fallopian tube, though described as an ‘ectopic pregnancy’ isn’t a legally recognised pregnancy. Treatment of such a potentially life threatening condition falls outside the Offences Against the Person Act 1861. I asked the N Ireland Department of Justice about a foetus and ‘life’ and ‘death’, and a spokesperson (to whom I am most grateful), reminding me that this is not legal advice, responded:
We have not been able to trace a legal definition of a fetus except in Jowitt’s Dictionary of English Law, 3rd edition, 31 October 2009. It defines fetus as :
“ A babe in the womb”.
You might also like to look at the judgement in R v McDonald  NI 150. One of the issues before the court was whether the child in the womb was capable of being born alive. The accused McDonald was alleged to have assaulted a pregnant woman who miscarried a fetus of approximately 27 weeks’ gestation.
The judge in the last paragraph set out the legal formula to be put to the jury as follows-
“The Crown must satisfy you beyond reasonable doubt that the baby was capable of being born alive. In this context “capable of being born alive” means that the child, at the point immediately before the defendant’s act destroyed its existence, had the real chance of being born and existing as a live child, that is to say breathing and living by reason of its own breathing through its lungs ( either naturally or with the aid of a ventilator) alone without deriving any of its living by or through any connection with the mother. In this context the Crown does not have to prove that the baby would have lived for any particular period of time provided that it can be shown that the baby would have lived even for a short period of time.”
This legal ruling has not been challenged, and implies that if a foetus has died in the womb, it is not illegal to perform manoeuvres to deliver it—though any clinician in this position should obtain legal advice.
You will remember the dreadful circumstances surrounding the ghastly tragedy of Savita Halappanavar’s death nearly three years ago (here). She was 17 weeks pregnant and presented to University Hospital Galway with an ‘incomplete abortion’. Classically, there are two types of spontaneous miscarriage or abortion; if the miscarriage is ‘threatened’, there is bleeding but the cervical os, the opening into the womb at its neck, is closed. If the miscarriage is ‘incomplete’, the cervical os is open, there is bleeding, and the pregnancy will not continue. The bleeding may come from the rupture of the membranes; it may come from detachment of the placenta (an ‘abruption’) from the womb; this will result in a large, raw area. At 17 weeks, the foetus is too immature to survive outside the womb; there is no question whatsoever about this. In Ms Halappanavar’s case she was refused an ‘abortion’ because, it is reported, the foetal heartbeat was present—amongst other reasons. Remember, it is possible to be dead yet still have a heartbeat. The usual treatment of an incomplete abortion is urgent evacuation of the contents of the uterus, for the open cervical os permits the entry of infection into a highly vascular area, a raw area unprotected by membranes, one very susceptible to infection which, untreated, will become overwhelming and thus fatal. The idea that the presence of a heartbeat must imply the presence of life is not correct; in Ms Halappanavar’s case, as it is reported, we cannot be sure whether her foetus was alive or dead; the presence of a heartbeat is not a reliable sign.