BlackBerry ID, and the Research In Motion products and services accessible using a BlackBerry ID, are not intended for use by anyone under the age of thirteen (13).
To determine âcessation of all functions of the entire brain, including the brain stem,â physicians must determine the presence of unresponsive coma, the absence of brainstem reflexes, and the absence of respiratory drive after a CO 2 challenge.
By placing a radioactivity counter over the head, one can measure the amount of blood flow into the brain. (See How Nuclear Medicine Works .) The cerebral blood flow study takes 20 to 30 minutes to perform. If there is no blood flow to the brain as demonstrated by this study, the brain is dead.A negative cerebral flow study is indisputable evidence of a dead brain. Normal cerebral blood flow study showing cranial space filled with blood. Cerebral blood flow study showing no blood entering the brain.Another confirmatory test is chemical: The patient can be given 1 mg of atropine IV.In the patient with an intact brain, atropine will dramatically increase the patient's heart rate. In a brain-dead patient, atropine will not influence heart rate.y placing a radioactivity counter over the head, one can measure the amount of blood flow into the brain. (See How Nuclear Medicine Works .) The cerebral blood flow study takes 20 to 30 minutes to perform. If there is no blood flow to the brain as demonstrated by this study, the brain is dead.