The tests used to determine brain stem death are simple but conclusive. They will only be carried out after doctors have established that the patient has suffered irreversible brain damage.
Before the tests are started checks are made to make sure that any factors which might affect the tests such as drugs or an extremely low body temperature have been eliminated.
The tests are done at the patient's bedside. First of all, a torch is shone into both eyes to see if the pupils react to the light. Then the cornea, which is normally ultra-sensitive, is stroked with a tissue or cotton wool. Next, painful pressure is applied to the forehead and the nose is pinched. Ice-cold water is then syringed into each ear in turn, which would normally cause eye movement. A tube is then inserted down the patient's throat to provoke a gagging or coughing response.
Finally, and most importantly, conditions are created which allow the patient to be removed from the ventilator for a short period of about ten minutes to see if they show any sign of attempting to breathe on their own. Patients who are brain stem dead will not react in any way to any of the tests.
This group of tests is carried out twice, at separate times. They are done by two senior doctors with special expertise in this area, neither of whom must be a member of the transplant team.
If the second set of tests confirms no evidence of brain stem activity the patient is declared dead.
The standards for certifying death by brain stem death are strict and are accepted medically, legally and ethically in the UK and in most other countries in the world.
View the Code of Practice for the Diagnosis of Brain Stem Death