Okay. Last bit before lunch. We've started using the term brain death in the late 1960s when medicine came up with the idea of loss of function of the brain and brain stem. We now tend to use the term death by neurological criteria. You may see the terms donation after determination of circulatory death. Patients may have withdrawal of life support and then go into non-perfusing rhythm for organ donation. I'm going to stick to death by neurologic criteria in this because that's what the topic for today. Why did anyone, why did medicine feel the need to come up with the term of death by neurological criteria? And it's very clearly they were looking for organs in patients who were never going to wake up for organ transplantation was the new frontier at the time. Who gets to decide whether the patient is brain dead or death by neurologic criteria or not? And it's really all over the map. Every hospital has to have a policy. So if you ever, who in this room declares brain death by him or herself? I'm sorry, as part of brain death. So about half of you. If you're going to do a death by neurological determination exam or do this evaluation, I highly recommend you print out the policy and have it with you when you do it. Because each hospital has its own policy. They're all expected to conform to national standards, but each hospital has to have its own policy. You want to be clear. You do everything exactly per policy because that's how you make sure nobody will come back and cause trouble for you later, doing exactly by the book, the way the hospital said to do it. Most of the time it specifies neurologists or neurosurgeons. It may specify medical intensivists. You can have any, and some hospitals will say any physician on staff or has done an in-service or some training can do it. You want to be very clear what your hospital policy specifies. For the record, our hospital policy for years said you have to have two physicians, at least one of whom is from neurology and neurosurgery. Now it says if one of them is a neurointensivist, then one physician is sufficient. If not, then you have to have two. You don't ever want to get the diagnosis of death by neurologic criteria wrong because you don't want anyone to come back later and say you hustled it up to get the patient's organs. So be very, very clear, be very precise, use the hospital policy. We're not talking about minimally conscious states, the new norm for vegetative states. We're not talking about potential for recovery and good outcome, we're talking about death by neurological criteria, yes, no, binary outcome. It is a cranial nerve exam and apnea because all mammals have to respire and inhale oxygen, get into their blood to breathe. If you can't breathe, if you have no drive to breathe, you can't survive on your own as a mammal. Beyond that, it's the cranial nerve and lower cranial nerve exam. You should be aware and you should tell families and use the evaluation, death by neurologic criteria doesn't mean no movement. There are movements which have nothing to do with the brain and brain stem. When you check reflexes, that's peripheral nerve and spinal cord. Doesn't require a brain stem to have a reflex. You can hit the patella reflex, the knee will jump. That doesn't need brain stem. So you can see reflexes in patients who are brain dead. Finger flexion will happen, the laser sign, flexion at the hip, facial myokami or little muscle discharges, muscle twitches. All of those are common and reliably seen in patients with death by neurologic criteria. If you don't tell patients' families about them first, they'll think you're trying to pull a fast one or they may think you're trying to pull a fast one or you're not paying attention to them. So tell families this is an exam of the brain and brain stem. It doesn't mean no muscle activity, doesn't mean no peripheral nerve activity. You have to try an apnea challenge if the patient can tolerate one. Because mammals breathe. If you're really into basic science, someone actually found the receptor in the brain stem that triggers breathing if you're into knocking out mice or whatever they've done here. When you talk to families about death by neurologic criteria, you want to be really clear and consistent in your communications. It's a good idea to have one person from the treatment team talk about this and it's a good idea to have one person in the family who's going to be the point of information. When you get in trouble, multiple family members after multiple clinicians, multiple vaguely slightly worded questions will get everybody in trouble, will lead to confusion and will make people angry. Because you're doing something that's a little strange. You're telling someone their loved one is dead when they can perfectly see the cardiac rhythm and hear the beep, beep, beep and see the ventilator. So you want to be very, very clear and consistent in the messaging. You do not need in the 2023 guidelines, you do not need to get a family's consent to do an evaluation for death by neurologic criteria. It's a standard exam. It's part of medical practice. You don't have to get permission to do it. You should probably tell them you're doing it because nobody likes to be surprised later, but you don't have to get informed consent to do that. There have been a couple of trials of allowing the patient's families to be present while you do the death by neurologic criteria evaluation. And it's kind of like those trials where you had patients' families be present during cardiac arrest. Some people find it traumatic, but most people like to see that you tried everything you could. Same thing here, in a prospective randomized trial, patients with a family member in the room during the brain death evaluation, those family members felt better about it and understood it more, even though the rates of grief and PTSD and quality of life were the same months later. I always offer the patient's family members a chance to be in the room while we do the evaluation. There's nothing to hide. It's a very standard evaluation. If you have any questions, the American Academy of Neurology has a website, they'll show you the exam. Here's the hospital protocol. We're doing it exactly the way we're supposed to, there's nothing to hide here. Updates to the 2023 criteria. You have to have a good reason for the patient to be brain dead. There's a case report in the Lancet of somebody who was making up a drip of a paralytic, got called away to a code, forgot to label the bag, came back, the bag is missing, oh, well, and then someone in another operating room suddenly looked like they were brain dead, went away when they changed the fluids. You got to have a good reason, typically means intracranial catastrophe. A Miller-Fisher variant of Guillain-Barré, Guillain-Barré that involves cranial nerves too, those patients can look brain dead. You must not declare them brain dead because it's a neuromuscular disease, not an intracranial catastrophe, and eventually their peripheral nerves start working again. So you usually have to have a diagnostic CT scan that shows a catastrophe. You have to observe them for 24 hours after rewarming to 36 centigrade if you're doing hypothermia for cardiac arrest still, you have to have sufficient time for other conditions if someone had shock or some other condition, whatever that means. The brain injury must be permanent. The patient cannot be, you have to have a systolic pressure of at least 100. You can use pressures for this, that's totally fine, and if they're on ECMO you have to have a MAP of 75. Please don't be that person that argues with me about MAP. And if the patient was getting Phenobar for some reason, it's got to be less than low, and you can't have a negative tox screen if it's indicated. No, a tox screen for marijuana is not a reasonable explanation for someone to have a brain death exam. But your hospital policy should be clear about that. They have changed what the ancillary tests are acceptable if you cannot do an apnea challenge for some reason. Gone are EEG. Boy, are the epileptologists happy about that. They hated doing this. Gone is CT angio, looking for no intracranial perfusion. The radiologists are glad to see that. They hated doing it. For a while, our colleagues in nuclear medicine didn't want to do it. Sorry, they're back on the table. SPECT is back, showing no intracranial filling, showing there's no radionuclide uptake in the brain, meaning there's no blood flow, meaning the patient's brain dead. You can do an angiogram, showing, again, no intracranial blood flow in internal carotid arteries and above. And you can do transcranial Doppler, showing what's called a water hammer pulse, or no evidence of cerebral autoregulation. These are now the acceptable tests for ancillary determination of death by neurological criteria. If you can't remember, just basically think, blood flow studies now. We've gone away from EEG. We've gone away from flat lines. It's basically, is there no intracranial blood flow? No talk on death by neurocriteria is completely out of the jockey's big mouth. Anyone else remember this case? The 14-year-old in California who was declared dead by neuro, had a catastrophic tonsillectomy, bled out, lost the airway. Competent people said this patient met the criteria for the diagnosis of brain death. The family said, absolutely not. He was able to get a court order. This patient was transferred to a facility in New Jersey where there was a heartbeat for the next four and a half years until there was a cardiac arrest. They've published Johnny McMath's MRI. Here it is. And you can see there's lost the corpus callosum, lots of shrinkage of the brain stem, shrink general atrophy, especially in the upper brain stem and the brain. This is the only case I'm aware of like this where someone was diagnosed brain death but then regained some respiratory function. It also means that once you've been declared brain dead, it is an irreversible process. It is an irreversible coma. Nobody wakes up and recovers after this. It probably happened where this patient recovered enough neurons to have some respiratory effort because she was 14. And children and teenagers are amazing. So if anyone asks, it has happened as far as we know one really well documented case and that person was permanent coma until she died of something else a couple of years later. So death by neurologic criteria. It doesn't mean loss of every neuron. It doesn't mean loss of peripheral nerves or muscle. It means no function on a bedside exam of the brain and brain stem once you've removed confounders. You have to have a good reason for this, like prolonged ischemia from cardiac arrest or intracranial catastrophe like hemorrhage, no brain stem function, and no apnea and no breathing apnea in a hemodynamically stable patient. Don't write positive brain death, negative brain death because people get confused. The patient meets criteria for brain death or the apnea challenge supports the diagnosis of brain death or does not support the diagnosis of brain death because people argue what positive or negative meant. You'll get a call 12 hours later because someone's panicked and isn't sure what you wrote in their word. They've done the wrong thing. And you want to be very open with families. I'm a neurologist. I'm an introvert. Most neurologists, we're a spectrum of people on the spectrum. We get that. But you've got to talk to people about death by neurological criteria. You don't want to surprise people. Families get really, really understandably very, very upset about this. And clinicians in other ICUs get really, really upset about this. So you want to be very clear. This patient may meet the criteria. Why or why not? You want to tell people what you're doing. You want to print out the hospital policy and show them and do exactly the evaluation. Otherwise people who think you're doing voodoo witchcraft get very upset. Tell people exactly what you're doing. This is a standard exam. It has been for decades and everybody knows exactly what it means. What do you do if the family doesn't believe you and they say, no, I think my loved one's not dead and you're wrong? Our hospital policy makes no provision for this because under hospital law, the hospital doesn't know anything to dead people. So as far as they're concerned, once the patient meets the criteria for death by neurological criteria, they're done. The hospital can't be sued after that. You're dead under state law. In terms of what do you do when the family's angry, we typically say understand. We typically won't disconnect ventilators, but we say we'll let the current bag of pressers run out but not replace them. We'll let the current bag of antibiotics run out but not replace them. We will typically humor and be nice and let things carry on. Other than John McMath, every patient that's brain dead becomes plain dead in a couple of days. Everybody eventually has an unresuscitatable arrhythmia. No, we don't do DNR status in patients who are brain dead because they're legally dead. We don't resuscitate legally dead people. When eventually those patients go into an unstable non-perfusing rhythm, we don't call a code, we don't do chest compressions, we don't give atropine. We just say, oh, your loved one has passed away, the heart has stopped, which is what happens to patients who meet the criteria for death by neurological criteria. Hospitals simply won't make policies because patients are legally dead then and they don't want to be in the situation of saying, why didn't you provide care to a dead person? They don't do that. It's exactly 12. We are right on time. Thank you so much for your attention. Thank you.

brain death

neurological criteria

organ transplantation

apnea test

diagnostic evidence