Science Forums 2

[MortenS]

I doubt she was brain-dead in the legal or medical sense, alxian. If she was, we must rethink our whole practice of donating organs, as brain-death is the criteria necessary before an organ is harvested from a donor. If someone said she was brain-dead, they most likely has not gone through all the procedures necessary to diagnose brain-death.

With partial brain death, you will suffer great brain damage, and total brain death is equal to death. When physicians speak about brain death, they usually mean brain-stem death, in addition to the death of the cerebrum and cerebellum.

Brain-stem death is legal death, because if not kept alive by respirators, the body will fail to function after just a a few minutes, since respiratiory control is located in the brain-stem.

The criteria for establishing brain-stem death are very strict:
1. The patient must be in deep coma which is not due to depressant drug, metabolic or endocrine disorders or hypothermia
2. The patient must be on mechanical respiration because of absence or inadequate spontaneous respiration. blocking agents such as curare or other drugs must be excluded as a possible cause for respiratory failure.
3. A firm diagnosis of the basic pathology must be available, and must be known to be due to irremediable brain damage.
4. Diagnostic tests for brain-stem damage must be unequivovally positive. The tests should be performed by two doctors, which has experience in such matters, preferably a doctor that knows the patient together with an independedt doctor.

The clinical tests to check if the patient are brain-stem death is as follows:
a. All brain-stem reflexes are absent, with fixed pupils, unreactive to light. Corneal reflexes absent. Spinal reflexes are irrelevant in diagnosing brain-stem death.
b. Vestibulo-ocular reflex negative when ice-water is introduced into the ears
c. No motor responses in any cranial nerves on response to painful stimuli
d. No gag reflex to a cathether introduced into the larynx and trachea
e. no respiratory movements when the patient is disconnected from the ventilator. P(CO2) should be in excess of 50 mm Hg as a stimulus to breathing.
All testing should take place when body temperature is above 35 degrees Celsius.

Only if all these tests are positive can someone be declared brain dead in the legal sense.

EEG, cerebral angiography and cerebral blood flow measurements can be performed in addition, but it will not give any more info than the clinical tests above. It will give some results on a graph, or a picture, and may be considered as objective documentation.