Thanks for coming, everybody. Great to see you. Here are my disclosures. None of these are pertinent to today's talk. I am going to show a number of patient videos. I would kindly request that you not take pictures or videos of the videos themselves. These are with the express permission of the families of these patients to whom we're very indebted. So please do respect that. Picking up where Matt left off, how many examinations are required? So there was a lot of debate about this, but we settled on at least one, of course, in adults. And two is probably better. When you think about a disease like this where we really have to be right 100% of the time, I strongly advocate for having two. And in fact, I think the best way to do it is to be blinded of each other, totally separate and independent. That's the soundest way to do it. In children, it is still two examinations for every patient, including two apnea tests. So that's a very big distinction between the two. And in children, you have to have an intervening period of 12 hours. It is arbitrary. The most important waiting period is before any evaluation for brain death. Please keep that in mind. If you have any question about the permanence of the condition, you shouldn't be doing any brain death evaluations in that patient. So in order to satisfy the pediatric community, which is reasonable that we put in a 12-hour intervening waiting period, but again, the most important waiting period is before any evaluation. I've gotten calls from different places around the country where an OPO representative has said, oh my gosh, they're going straight to SPECT again. Can you please do something? Please do not go straight to ancillary testing. If you suspect the patient might be brain dead, clinical evaluation is really going to be the most important way to determine somebody. And ancillary testing should not be a crutch. In fact, even when you know that you're going to have to do ancillary testing because some confounding in that patient, you still do all of the clinical examination that you can, including the apnea test, if you can. Because if you find signs of life on that, there is no indication to get an ancillary test. So always test everything that you can when you can to the degree that you can. All right, the clinical evaluation. Let's talk about the neuro exam. And this will probably be a review for everybody here. But I'm going to tell you a few things about technique that may be helpful. This should sound familiar. Three things in brain death, coma, no brain stem reflexes, and apnea in the setting of a carbon dioxide challenge. Coma means no responsiveness to any kind of stimulation, visual, auditory, tactile stimulation. The tactile stimulation should only give you spinally mediated responses, nothing that looks cerebrally mediated. You have to stimulate in all four limbs and on the cranium. Somebody may have a c-spine injury or a bad peripheral neuropathy. And so you have to stimulate on the cranium also. How do you do that? Well, I want you to take your index finger and touch your eyebrow. Go with me. Humor me for a second. Go about 2 3rds of the way out, and you're going to feel your superorbital notch. If you press right there, that's your superorbital nerve. It hurts like the dickens, right? Don't press too hard. That's a great place to give noxious stimulation on the cranium. Another one is bilateral TMJ pressure. You don't have to press that hard for it to be noxious. And then there's the old nasal tickle, the COVID swab we all see nowadays. And that's also very stimulatory. Sometimes you'll see a movement, and you're not sure if it came from the brain or the spinal cord. Phone a friend. Bring in somebody to take a look who has more experience, perhaps. And if you're still not sure, then you may need to get an ancillary test in that situation. There are a number of spinally mediated reflexes that have been published. This is from the guidelines themselves. I'm not going to go through these in any detail, but keep in mind that they have been described. And that may be helpful for you to say, oh, somebody else described that before as a spinal reflex. Let's show how to do a blink-to-visual threat. So you hold the eyes open, and you come in with your hand flat. And you come right down the center and from the sides. The reason why my hand is flat, if you take your hand and go like this, you're creating a wind wave, and you're testing a corneal reflex. I don't want to test a corneal reflex yet. I'll test it when I'm ready. So that's how you test a blink-to-visual threat. Here's motor testing. You stimulate on the nail bed. You can see that this patient is not in coma. He opens his eyes, and he has some head turning with this. He has a little bit of extensor versus flexor posturing. Again, you always pinch immediately on the arm also. If you move towards a noxious stimulus, that's always pathological. You should move away. Stimulating on the legs is the same principle. You're going to stimulate typically at the great toe, right at the base of the nail, not on the skin, because it's easy to cause skin breakdown there. And you see this looks like triple flexion. But when I pinch him on the knees immediately, he has more complex movement of the legs that looks maybe triple flexion. But on the right leg, it looks maybe purposeful. So you just write down what you see when you see it. Pupillary reactivity is obviously extremely important to test for. The pupils in brain death should be typically 4 to 6 millimeters. They can be anywhere 2 to 9 millimeters. If they're less than 2 millimeters, you have to worry about drug intoxication, particularly with opioids. A magnifying glass can be helpful, or pupillometers can be helpful with this as well. I don't own any stock in the companies. This is my hardware store flashlight with a magnifying glass. That's my own pupillometer. It costs about $6. This one costs about $4,500. This is an automated pupillometer. But the nice thing about these is that they automatically check a second time. They do not like to not get a reaction on the pupil. And so 1, 2, 3, boom. Oh, I missed it. Boom, there it goes. It shines a light again. It's always automatically going to check a second time as well. All right, who here? Show of hands, who uses a saline squirt or a sterile water to check a corneal reflex? Anybody? I do. I do it all the time, every day, multiple times a day. If you get a corneal reflex to that, they've got a corneal. So you're good, and you haven't injured the cornea in any way. But that's not a potent enough stimulus to be definitive in brain death or post-cardiac arrest. And where you touch on the eye is important also. This is a heat map from over 900 intensivists and neurologists saying, where do you touch on the eye? And a lot of people were pretty far lateral. Some people miss the eye entirely, which is sad. But the farther you get out on the sclera, the less sensitive the eye is. So you really want to go right at the border. Sorry. I didn't want to do that. Help. I'm working on it. You go right at the border of the iris right here. And I'll show you what it looks like. And you want to give some pressure. So this looks gross. You are not going to injure the patient. But this is how you know that you've given a potent enough stimulus that the patient does not have a corneal reflex. That's how you test it properly. What are doll's eyes? Somebody writes doll's plus in the chart. Is it an old doll? Is it a new doll? The eye is supposed to move. It should be called the oculocephalic reflex. And it's tested only when you have integrity of the c-spine and an intact skull base as well. You briskly rotate the head horizontally. You should see no eye movements in a brain dead patient. You want to stabilize the endotracheal tube, as you see me doing now, and hold the eyes open with the other hand. And you move your hands in unison so you do not dislodge the ET tube. Again, in brain dead, there is no movement. This is what it looks like in a normal patient. This is my friend Fernando, who has a very nice brain stem. If you can't test the oculocephalus because of the c-spine or the skull base, it's the one thing you can skip, provided that you can still do the oculovestibular or the cold calorics. That's an important thing to remember. This is the one test that you can skip. How do you test the oculovestibular test correctly? So first of all, look in the ear to make sure you've got a clean path to the tympanic membrane and that the tympanic membrane is intact. You elevate the head of the bed to 30 degrees. You irrigate one ear at a time with ice-cold water. And you're observing for one minute to see if there's any eye movements. Again, in brain death, there should be no eye movements. You see, it's a two-person operation. Somebody is helping me to hold the eyes open while I instill the water in one ear at a time. And you wait five minutes before testing the other ear. And founders for these tests include ototoxic drugs, as you can see listed here. More commonly, like in a TBI patient, you're going to have a restrictive defect because they've got trauma and edema on their face and their eyes just simply can't move. Again, you test what you can when you can, but you're going to need to get an ancillary test in that situation. You should see no facial movement to noxious stimulation. We talked about the places to stimulate. You can get facial myokymias, which are spontaneous discharges of the facial nerve, but should not happen in response to anything you do to the patient. They should have an absent gag and an absent cough. And they should not be over-breathing the ventilator. You guys all know what a nasal tickle looks like. You can see this on both sides here. Here's a gag reflex. Sorry. Oh, what did I do? Oh, no. This is very bad. OK, here it goes. So this patient had a very large tongue, and I had to squeak the Q-tip past the tongue and stimulate both sides of the soft palate. And cough reflex, everybody knows how to do inline suctioning, so I'm not going to show you how to do that. This is the auditory response by cough. Sorry. This is a video from the New England Journal that we published a couple of years ago that goes through all of this in five minutes. If you haven't done a brain death evaluation in a while and you're going in to do one, this can be very helpful for you. Five minutes, free on New England Journal's website. Just search brain death on NEJM. Apnea testing, coming to the close here. So apnea testing should only be done in a controlled environment in the ICU by skilled providers who know what they're doing. Prerequisites, they have to be normotensive, which means now not only is systolic greater than or equal to 100, but a MAP also of 75 or greater. In PEDS, it's above the fifth percentile. They have to be normothermic, and they have to be uvolemic. In patients who've had DI, they may be hypovolemic, and they'd be at risk for getting hypotension during the exam. You want to establish eucapnea. Unless they're a known CO2 retainer, I'll get back to that in just a second, and a normal pH. And I recommend getting a functioning A-line for every patient. What if they're a CO2 retainer? Well, if you know what their baseline is for their CO2, that's the baseline that you start with for the test, and you're going to go for 20 points above that elevated baseline. If you suspect it, but you don't know what their baseline is, then you can estimate going above a certain level, maybe trying to get a PCO2 of 70, but you have to get a ancillary test in that situation. So that's the new guidance regarding CO2 retention. Everybody gets pre-oxygenated, you establish eucapnea, and you disconnect the patient from the ventilator. There's no question then whether the patient took a breath or not. That's at least in adults. In children, they do it differently. You want to provide oxygen to the level of the carina at a flow rate of no faster than 4 to 6 liters per minute. Faster than that, you can cause barotrauma and wash out CO2. There are alternative methods that can be used, including a flow-inflating resuscitation bag with a functioning PEEP valve. That's commonly done in children. You typically observe for eight to 10 minutes. You can send ABGs along the way. What you're looking for is an absence of respiratory effort. You bear the chest and the abdomen to look for any respiratory effort, and you want the PCO2 to be above, I'm sorry, 60 or above and 20 above. That and is new. It used to be or. It's and. It's both, and especially in an elevated baseline. And you have to have the pH now less than 7.3. That's new also. You can go for longer, but you, again, have to re-establish hyperoxygenation and normocarbia. You abort the test if they breathe, obviously, if they drop their blood pressure, if they have a progressive O2 sat less than 85%. Cardiac arrhythmias with hemodynamic instability, but get an ABG right before you reconnect them to the ventilator. I recommend hyperventilating everybody, whether or not they got hypotensive. The patient is acidotic. You caused an acidosis. That's the whole point. To rapidly correct that, you can do gentle hyperventilation. We do provide new guidance for apnea testing on ECMO, and this is very important. There's two different kinds of ECMO, obviously, and so whether they're on VA or VV ECMO, we have blood pressure targets, and we have the places that you need to sample the arterial blood gases from to make sure that you're consistent with what the brain is seeing. So take home messages from my portion of the talk. Use meticulous technique. This is a matter of life and death, literally, so please do it correctly. Always perform everything you can when you can. Do not go straight to ancillary testing. The only part of the clinical exam you can skip is the oculocephalic, only if contraindicated, and only if you can do the oculovestibular. Please be aware of the new blood pressure goals for adults and children, and the new guidance regarding CO2 retention and patients on ECMO. And practice, practice, practice. This is a great place to use simulators to get really good at your exam and to go through scenarios. So I think that's it. Thank you very much for your attention. Thank you.

brain death evaluations

clinical evaluations

apnea tests

brainstem reflexes

ECMO guidelines