الفهرس 
Vascular Supply of The BrainOnly 14 pages are availabe for public view
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Abstract
The following manifestations are occasionally seen and should not be misinterpreted as evidence for brainstem function:
1- Spontaneous movements of limbs other than pathologic flexion or extension response.
2- Respiratory-like movements (shoulder elevation and adduction, back arching, intercostal expansion without significant tidal volumes).
3- Sweating, flushing, tachycardia.
4- Normal blood pressure without pharmacologic support or sudden increases in blood pressure.
5- Absence of diabetes insipidus.
6- Deep tendon reflexes; superficial abdominal reflexes; triple flexion response.
7- Babinski reflex (NY State Department of Health Guidelines of Determining Brain Death, 2005).
Step 4: Interval Observation Period
After the first clinical exam, the patient should be observed for a defined period of time for clinical manifestations that are inconsistent with the diagnosis of brain death.
Most experts agree that a 6 hour observation period is sufficient and reasonable in adults and children over the age of 1 year. Longer intervals are advisable in young children (NY State Department of Health Guidelines of Determining Brain Death, 2005).
Step 5: Repeat Clinical Assessment of Brain Stem Reflexes
The exam as described in Step 3 should be repeated in full and documented (NY State Department of Health Guidelines of Determining Brain Death, 2005).
Step 6: Apnea Test
Generally, the apnea test is performed after the second examination of brainstem reflexes.
The apnea test need only to be performed once when its results are conclusive.
Before performing the apnea test, the physician must determine that the patient meets the following conditions:
Core temperature ≥ 36. 5°C.
Euvolemia. Option: positive fluid balance in the previous 6 hours.
Normal PCO2. Option: arterial PCO2 ≥ 40 mm Hg.
Normal PO2. Option: pre-oxygenation to arterial PO2 ≥ 200 mm Hg. (NY State Department of Health Guidelines of Determining Brain Death, 2005).
Step 7: Confirmatory Testing as Indicated
In some patients, skull or cervical injuries, cardiovascular instability, or other factors may make it is impossible to complete parts of the assessment safely. In such circumstances, a confirmatory test verifying brain death is necessary.
1- Angiography (conventional, computerized tomographic, magnetic resonance, and radionuclide): Brain death confirmed by demonstrating the absence of intracerebral filling at the level of the carotid bifurcation or Circle of Willis.
2- EEG: Brain death confirmed by documenting the absence of electrical activity during at least 30 minutes of recording that adheres to the minimal technical criteria for EEG recording in suspected brain death as adopted by the American Electroencephalographic Society, including 16-channel EEG instruments.
3- Nuclear brain scanning: Brain death confirmed by absence of uptake of isotope in brain parenchyma.
4- SSEPs: Brain death confirmed by bilateral absence of N20-P22 response with median nerve stimulation.
5- TCD ultrasonography: Brain death confirmed by small systolic peaks in early systole without diastolic flow (NY State Department of Health Guidelines of Determining Brain Death, 2005).
Step 8: Reasonable Accommodation
When an objection to brain death based on religious or moral grounds is raised, physicians should follow hospital policy for providing reasonable accommodation (NY State Department of Health Guidelines of Determining BRAIN Death, 2005).
Step 9: Certification of Brain Death
Step 10: Withdrawal of cardio-respiratory support in accordance with hospital policies, including those for organ donation (NY State Department of Health Guidelines of Determining Brain Death, 2005).