My sister was without oxygen for an extended period. she's on life support but her pupils are blown. is there any chance she'll come back or are we prolonging the inevitable?

The : The brain requires a constant, robust supply of oxygen and glucose (carried by the blood) to maintain function and to avoid injury. We get an intuitive sense of this from phenomena like fainting, or when wrestlers use "choke holds" on their opponents. Depending on the circumstances, it can take only a couple of minutes for the brain to be permanently injured by lack of blood supply. This injury is called an "anoxic brain injury" or a "hypoxic-ischemic brain injury." a serious anoxic brain injury often results in a patient who has a degree of coma, or is brain dead, and is usually on a breathing machine (called a ventilator). There are a number of ways to measure the chances of "coming back" from such a serious situation. These include very simple things like a neurological examination done under very specific conditions that exclude the chances of mistake, including eliminating any medications that could produce sedation or paralysis, correcting any severe problems with blood chemistry (like low blood sugar), and making sure the patient warm. Very good research has shown that two examination findings are very good at predicting a future of severe neurological impairment or death when they are present at the 72 hour point. These two findings are: 1) absent pupillary reflex (constriction of the pupils to light) or absent corneal reflex (blinking when a drop of water or other stimulus is touched to the surface of the eye); 2) no movement or something called "extensor" movement, when an uncomfortable stimulus is applied to the limbs. When doubt remains, there are additional tests that can be done. These include brainwave tests (including eeg and something called somatosensory evoked potentials or sseps), brain imaging studies, and lab tests (including something called neuron-specific enolase). In most cases, these additional tests do not have to be done. Even when patients who experience cardiac arrest receive a fairly new treatment in which they are chilled to below normal body temperature (called hypothermia), studies indicate that absent pupillary reflexes at day 3 are predictive of poor outcome. There is also the rule of common sense. Each day that someone doesn't "come back" decreases the chance that they will. For example, about half of all patients who will awaken will do so by day 2, and about 90% of patients who will awaken will do so by day 3. As the days march on, the chances get smaller and smaller, reaching a point comparable to the miraculous. While almost everyone likes to hope for miracles, we also seem to be able to recognize reality at the same time. It is tempting to want "one more day" to see if things change, but each day also comes at a considerable risk to the patient, whose body is exposed to challenges like blood clots, organ failures, and infections with each passing moment. Doctors and nurses are all very familiar with the facts and emotions behind such sad events and are usually eager to be available for family conferences to discuss specific situations.

I : I am very sorry to hear about this, and as you have likely heard by now (avvo says you posted 19 hours ago) there is not likely much good news i can give. "blown" pupils are dilated and unreactive pupils, and they indicate that the brain has swollen so much that the medial-inferior (lower inner) surfaces of the temporal lobes have herniated across the tentorium and compressed the third cranial nerves (oculomotor nerves). When these nerves don't work well or at all then the pupillary light reflex is lost, so the pupils dilate and stay that way. This is usually a sign of irreversible brain damage of a severe nature, and few people recover from a state in which they have both pupils blown on the basis of oxygen deprivation. This is not necessarily equivalent of "brain death", and your sister's doctors will have to determine if she is still alive or is brain dead but being mechanically ventilated and supported so her heart has not yet stopped. Withdrawal of care for someone declared brain dead is usually automatic, but such withdrawal for someone who is comatose but not brain dead is not. Did you sister leave an "advanced directive" or "living well", indicating how much she wanted done in case of severe neurological impairment? If not, it becomes the duty of the closest living relative(s) or of someone with appropriate power of attorney to consult with the doctors about possible withdrawal of care or about her prognosis if kept alive by artificial means. Again, sorry you are in this position.