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The Neuro Exam
25 Plays1 year ago
Disturbances in neurological function due to primary neurological disorders or organ failure from critical illness are common in patients admitted to the ICU. In this episode, Dr. Zanotti discusses the neurological physical exam in the ICU. He is joined by Dr. Adam Rizvi, a neurologist with Neurocritical care and vascular neurology fellowship training who currently practices critical care, neurocritical care, and tele-neurology/tele-stroke in several hospitals in California. In addition to his clinical work, Dr. Rizvi is an accomplished educator and researcher.
Additional Resources:
Neurological examination of critically ill patients: a pragmatic approach: Report of an ESICM expert panel. Intensive Care Med 2014. https://pubmed.ncbi.nlm.nih.gov/24522878/
Critical Matters Podcast episode: Brain Death / Death by Neurological Criteria. Host: S. Zanotti. Guest: D. Greer: https://soundphysicians.com/podcast-episode/?podcast_id=342&track_id=1677810255
Clinical Neuroanatomy Made Ridiculously Simple. Edition 6. Stephan Goldberg, MD: https://amzn.to/4cC34uZ
Books mention in the episode:
Meditations. By Marcus Aurelius. Translation by Gregory Hayes: https://amzn.to/4eBxK1d
Recommended
Transcript
Welcome and Introduction
00:00:06
Speaker
Welcome to Critical Matters, a sound podcast covering a broad range of topics related to the practice of intensive care medicine.
00:00:14
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Sound provides comprehensive critical care programs to hospitals across the country.
00:00:19
Speaker
To learn more about our programs and career opportunities, visit www.soundphysicians.com.
00:00:26
Speaker
And now your host, Dr. Sergio Zanotti.
Neurological Disturbances in ICU
00:00:32
Speaker
Disturbances in neurological function due to primary neurological disorders or organ failure from critical illness are common in patients admitted to the ICU.
00:00:41
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Monitoring in the ICU is extensive and often focused on cardiopulmonary function.
00:00:47
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In today's episode of Critical Matters, we will focus on semiology, specifically the neurological examination.
Guest Introduction: Dr. Adam Rizvi
00:00:55
Speaker
Our guest is Dr. Adam Rizvi, a neurologist with neurocritical care and vascular neurology fellowship training who currently practices critical care, neurocritical care, and teleneurology telestroke in several hospitals in California.
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In addition to his clinical work, Dr. Rizvi is an accomplished educator and researcher.
00:01:13
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It is a pleasure and honor to have him as our expert guest today.
00:01:16
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Adam, welcome to Critical Matters.
00:01:19
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Thank you, Sergei.
00:01:20
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It's a pleasure to be here.
Importance of Subtle Neurological Observations
00:01:22
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Well, this is certainly a topic that we don't often discuss, but that I believe is super relevant to what we do every day at the bedside.
00:01:31
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And as a more of introduction, I wanted maybe to hear your perspective on why this is an important topic for a bedside critical care clinician.
00:01:43
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I've had this experience of seeing
00:01:48
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patients in two lights.
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The first being when I'm trying to formulate a diagnosis is asking myself, what can I not afford to miss?
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And these are usually the severe emergencies like a subarachnoid bleed or a large stroke, for example.
00:02:04
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These are things that I can't afford to miss, so I have to be on guard.
00:02:09
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But then there's another question of really as the clinician diagnostician, what is this most likely to be?
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And that's where the sleuthing and the detective work comes in.
00:02:20
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And that requires a much more subtle approach.
00:02:24
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And I think for the neurological exam,
00:02:29
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we often focus on the first, right?
00:02:33
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Large stroke, large bleed.
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We can't afford to miss these.
00:02:36
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But then as the days go by in the ICU, sometimes that latter approach of really getting out that magnifying glass, really paying attention to the subtleties in the exam, that'll allow us to pick things up that can ultimately save the patient a lot of trouble in the long run.
00:02:57
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Perfect.
00:02:57
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And what do you think is important from a neuro perspective for the non-neurologist to recognize in terms of what happens in the ICU with neuro function?
00:03:09
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Well, I'd say that a lot of common things, the most common things I can think of are while a patient is intubated and sedated, for example, depending on how
00:03:20
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prothrombotic they may be, a stroke can occur.
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And if we're not doing our daily SATs and SBTs, we might miss something that just a daily neuro exam might have caught.
00:03:32
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And then
00:03:34
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Maybe some other common conditions might be critical illness, polyneuropathy and myopathy.
00:03:40
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These things slowly creep up, and if we are paying attention, we can catch it early and really take aggressive action to prevent it from worsening.
00:03:50
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I think those are some common neurological conditions in the neuro ICU.
00:03:55
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Of course, there's a whole slew of other things that can occur, like seizures and
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and infection, CNS infections.
00:04:02
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But I'm just giving a brief overview of the more common things.
00:04:05
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Excellent.
00:04:06
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Now, as we start talking more about the different aspects related to the neuro exam and localization of injuries and how to do it, I would like to hear a little bit from you
00:04:20
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your perspective on maybe comparing the traditional internal medicine approach to examination and diagnosis versus the neurological approach?
Neurological vs Internal Medicine Diagnosis
00:04:31
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You know, it's interesting.
00:04:33
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I hadn't even realized there was a potentially different way of approaching
00:04:39
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neurological diagnosis until one of my mentors in residency pointed it out to me and the way he did it and it's it stuck with me ever since then is he said okay I'm going to give you a constellation of symptoms and I want you to tell me what you're thinking a patient comes to you and they complain of dyspnea on exertion you notice on exam that they have pedal edema
00:05:05
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And maybe that this has been going on for some time and when they really push themselves, they start to get a little bit of chest pain and pressure on their chest.
00:05:13
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Now, when you any internal medicine doctor would look at that and say, OK, we have this constellation of symptoms, angina, pedal edema, signs and symptoms and dyspnea on exertion.
00:05:26
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Well, what organ system, what disease entity do you narrow in on?
00:05:32
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And with enough experience, we know we narrow in on the heart.
00:05:36
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This is likely a cardiomyopathy or an MI, something to do with the heart.
00:05:42
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And that we don't even realize, we take for granted that our mind works that way.
00:05:49
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We take constellation of symptoms and we think what organ system is going on.
00:05:55
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In the neurological approach, really we take a constellation of symptoms
00:06:02
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And then we ask yourself not what organ, we ask yourself where along the neural axis can I localize this?
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And we apply Occam's razor.
00:06:13
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We try to have one point along the neural axis that can explain all the symptoms.
00:06:19
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So I'll give you, for example, someone suddenly experiences equal weakness of the left face, left arm and left leg.
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and the arm, the leg and the face are equally weak.
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There's no gradient, but there's only motor dysfunction.
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Now, that's a key feature here.
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When you hear that the arm and the leg are equally weak, that should trigger alarm bells.
00:06:54
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When they're equally weak, we may be dealing with a subcortical process, specifically the internal capsule.
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or the just outside of the internal capsule that causes motor weakness that is both equal face arm and leg because there's a little homunculus in the internal capsule now notice how that constellation of constellation of symptoms i could localize to a very very tiny point along the neural axis and
00:07:25
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I noticed, okay, there weren't any cortical signs.
00:07:27
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So let me jump straight to the subcortical pathways.
00:07:31
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That's the kind of thinking I think we can learn to take on.
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Ask yourself where along the neural axis is this?
00:07:41
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I think that's a perfect segue to the neural
Understanding the Neural Axis
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access.
00:07:43
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So maybe, Adam, you could give us a little bit of a general overview of the neural access for the non-neurologist.
00:07:49
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Maybe take us back to med school to have some basic thought, and then we can start talking about how we can apply that clinically.
00:07:58
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Yeah, that's really great.
00:08:00
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These are situations where I love to have a visual, but I'll try to paint the visual with words.
00:08:07
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Imagine more or less the neural axis is as the name implies a pillar or a column, like an axis, and you're going from the top to bottom.
00:08:16
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In this case, the different levels of along the axis correlate with different body parts.
00:08:24
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So let's start with the top.
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At the top portion of the neural axis is your cortex.
00:08:30
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And let's just say we're dealing with motor
00:08:34
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function so we're dealing with the um motor strip right along the parietal cortex when it's in the cortex it has some very unique cortical signs that tip you off that you're dealing with a cortical problem and we can go into that later on for now let's just cover the whole neural axis
00:08:52
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You follow the axons from that soma, the body of the nerve cell, and you notice it goes down to subcortical structures.
00:09:02
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It gets funneled down into the corona radiata, and then it goes down into the internal capsule, then it goes all the way down into the cerebral cruce of the brainstem, the midbrain, and then it goes through the brainstem, midbrain, pons, medulla, then it goes to this spinal cord,
00:09:21
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Now as you leave the spinal cord, let's say at the level of the arm, you go through nerve roots.
00:09:29
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And then the roots become a plexus, they form a plexus.
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And then from the plexus, it becomes a nerve, a peripheral nerve.
00:09:39
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And now if you recall, peripheral nerves, they end right at the level of the muscle.
00:09:45
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And there's a neuromuscular junction, which is also part of the neural axis.
00:09:50
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And what people don't realize is it keeps going.
00:09:52
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past the neuromuscular junction, you have the muscle and everything to do with the ability for the muscle to contract down to the level of myosin and actin and that whole process.
00:10:06
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Now, from the very top, the cortex, all the way down to the muscle, that is the neural axis.
00:10:12
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And so you can have pathology at the cortex, at the subcortical level, at the level of the brainstem, at the level of the spinal cord,
00:10:22
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at the level of the nerve root, nerve, we didn't talk about the ganglia, and the neuromuscular junction and the muscle, and each level has its own etymological term to it.
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Would it be okay for me to dive into that?
00:10:40
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I think that would be great if we can cover some of the basic localization etymology terms.
00:10:46
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Yeah.
00:10:48
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So when you involve anything that involves involves the brain, typically has word encephalo, encephalo meaning head.
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And then as you move down, you involve the spinal cord and the spinal cord
00:11:10
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It's called myelo.
00:11:12
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So you add a brief note here.
00:11:15
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In terms of naming pathology, you add the word pathos, which means to suffer, to the end of the prefix.
00:11:22
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So in the case of a spinal cord pathology, it's myelopathy, myelopathy.
00:11:29
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uh milo means bone marrow because way back in the day people thought the spinal cord um the vertebral column had bone marrow in the center of it they didn't really know that it was a spinal cord they thought it was bone marrow but that's where the name came from milo now as you go to the nerve root
00:11:46
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Here you have radiculo, which interestingly is related to the root radish, right?
00:11:54
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Radix.
00:11:55
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Anything with that term radix, radish, radic means root.
00:12:01
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And so you add root and pathos radiculopathy.
00:12:05
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And that gives you the term for a nerve root problem.
00:12:09
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When you have a problem with the nerve ganglion,
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ganglions contain the body of a neuron.
00:12:19
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And so you would call, you would, and if there's a pathology there, you would call it a neuronopathy.
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The whole word neuron, neurono, pathos is put together.
00:12:31
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And that's a,
00:12:32
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distinct from neuropathy.
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A neuropathy is just a little bit further down the neural axis.
00:12:37
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It's a problem with the nerve itself, but the nerve body is neurono-pathy or neuronopathy.
00:12:45
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And if you keep going down, obviously going all the way down to the muscle, myo is the term for muscle, and you add pathy to it and it's myopathy.
00:12:56
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So every portion of the neural axis has its own term assigned to it.
00:13:02
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Could you mention some of the unique features of these lesions along the neural axis?
Cortical vs Subcortical Lesions
00:13:08
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Yeah, I think for intensivists and anyone doing critical care, the further up the neural axis is probably more critical.
00:13:22
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I think one of the more powerful, I would say high yield,
00:13:28
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distinctions is between the cortex and the subcortical structures.
00:13:35
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So if you were to imagine the homunculus of the brain, for example, there's an image, if you pull this up, anyone listening, just Google homunculus cerebral vasculature, and you'll see a picture of a somewhat of a distorted man overlying the cortex of the brain.
00:13:57
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and you'll see that the leg lies in the ACA, the anterior cerebral artery territory, right in the center where the fox is and as you move laterally you get into the MCA, middle cerebral artery territory, and that's where you have the arm and the face and the hand.
00:14:23
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Now, interestingly, if you have a large MCA stroke, you'll notice how the face, arm, and hand are predominantly overlapping that territory.
00:14:37
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And so that's why when someone comes in with an MCA stroke, you'll notice there's a big difference between the weakness of their face and arm as compared to their leg.
00:14:46
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The leg more or less is spared.
00:14:48
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It might be weak a little bit,
00:14:50
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but it's the face and the arm and the hand that tends to get much more weak.
00:14:56
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But if you go deeper to the subcortical structures, like the internal capsule or the thalamus or even the brainstem, then all the fibers from the cortex are funneling down into a narrow area and you'll get equal weakness.
00:15:12
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Face, arm and leg are all equal.
00:15:15
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And that, as with the early example, that gives you a clue that this is a subcortical process.
00:15:22
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Um, and now there's four, this is a great takeaway.
00:15:25
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Maybe if there's one takeaway, uh, the listeners can have on this are as a mnemonic that I use for identifying very, uh, clear cortical signs.
00:15:38
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There are four major cortical signs and they map onto the four lobes of the brain.
00:15:42
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The mnemonic I use is hand.
00:15:45
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h stands for homonymous hemianopsia and that means if you get a pca posterior cerebral artery pca stroke or a pca bleed then you will have the contralateral uh hemianopsia meaning your field you'll have you'll have a visual field cut so that h stands for the hemianopsia now that's the occipital lobe now if you move uh laterally to the left
00:16:14
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hemisphere, the left parietal lobe, the left temporal lobe, and the left frontal lobe portions of it, you can get aphasia.
00:16:22
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That's what the A is, aphasia.
00:16:24
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You can have global, you can have frontal parietal aphasia or expressive, receptive, respectively.
00:16:32
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That A, anytime anyone has aphasia, you know the cortex has been involved.
00:16:39
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That's H-A-N-
00:16:41
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is neglect and that's the typically the right parietal lobe so if someone has neglect you can pretty you can be sure there is cortical involvement
00:16:51
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And then D stands for deviation, deviation of the eyes.
00:16:55
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And that's where there's a frontal stroke or a frontal bleed.
00:16:58
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Your eyes will go towards the direction of the injury.
00:17:04
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You'll look towards the injury.
00:17:05
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So if I had a stroke on the right frontal lobe, my eyes will look to the right.
00:17:10
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And you might say, okay, what's the relevance of this?
00:17:12
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Well, one, if you know the patient's demonstrating a cortical sign, chances are,
00:17:18
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they probably developed a large vessel occlusion and you can take action on that really quickly.
00:17:23
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And this has happened more times than I can count in the ICU.
00:17:26
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And the other thing that it might clue you into is because the cortex is now involved, lesions on the cortex are very prone to seizures.
00:17:34
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And so you can take action in that regard, at the very least be aware that that might be something happening while they're in the ICU.
00:17:42
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That's one example of why this mnemonic might be helpful.
00:17:46
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Awesome.
00:17:47
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No, and I think that in addition to that, we often might get called to a bedside because the nurses identified some acute finding that wasn't documented before.
00:17:57
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And I think that being able to differentiate what could potentially be, like you said, life-threatening or time-sensitive in terms of action versus something else, what comes to mind immediately is they call me for a
00:18:10
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possible code stroke in the ICU in a patient post-eparum preeclampsia, eclampsia, receiving magnesium.
00:18:18
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And obviously it's not focal, it's symmetric.
00:18:23
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You quickly tell them, no, no, just stop the magnesium, right?
00:18:25
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I mean, so doing a quick exam can definitely also prevent us from
00:18:29
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going down the wrong route and adding tests and extra cost to that care.
00:18:35
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Now, we talked about the cortex, obviously, and as we move down subcortical, another area that is very important, I presume, for all intensivists is the brainstem.
Brainstem Anatomy and Reflex Arcs
00:18:47
Speaker
Can we talk a little bit about the brainstem, maybe overview of its anatomy and function and why you think it's so critical for us as intensivists, and then talk a little bit about what we'll find there?
00:18:57
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Yeah, my pleasure.
00:18:59
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Brainstem is critical.
00:19:02
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Obviously, it has a very important real estate.
00:19:07
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Well, let's review the anatomy a little bit.
00:19:10
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Going from top to bottom, there's three portions of the brainstem.
00:19:14
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That's a good way of looking at it.
00:19:17
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The top is the midbrain.
00:19:20
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The middle is the pons, and the bottom is the medulla.
00:19:25
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Now, in terms of
00:19:28
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They all play extremely important roles, and I think we would spend multiple hours if we spent the time going into it.
00:19:35
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But the midbrain is responsible for several things.
00:19:40
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There's a particular reflex arc attributed to each portion of the brainstem, and I really like that.
00:19:48
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demonstrating it this way because it simplifies the brainstem for a lot of people and it's a great way of assessing the brainstem function especially when you're dealing with coma exams which we can go into if we have time the as you know there's 12 cranial nerves but you can boil down all those cranial nerve testing into three reflex arcs that covers all three portions of the brainstem so let's talk about the midbrain
00:20:18
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The midbrain has a reflex arc involving cranial nerves three, two and three.
00:20:25
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Now, if anyone remembers, two is what allows you to receive light.
00:20:31
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Light goes into the retina.
00:20:32
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It travels down the optic nerve.
00:20:33
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That's two.
00:20:34
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It goes all the way down to the Edgar Westfall nucleus in the midbrain.
00:20:39
Speaker
It loops around and it comes back out in the oculomotor nerve.
00:20:43
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That's three.
00:20:47
Speaker
Checking the pupillary response is a great way to indirectly assess the integrity of the midbrain.
00:20:55
Speaker
And this is really nice too, because in someone who you are worried might have uncle herniation,
00:21:02
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meaning there's pressure coming from above, the very first portion of the brainstem that will be hit is the midbrain.
00:21:11
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And so I would spend special attention on the midbrain.
00:21:18
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Now, moving down, we have the pons.
00:21:21
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The pons is the name pons comes from a French word, which means bridge.
00:21:26
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And that's because the fibers go transverse, connecting both cerebellar hemispheres.
00:21:33
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So instead of being vertical, most of them are actually horizontal and form like a bridge.
00:21:39
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It's this bump that we see.
00:21:41
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And the
00:21:42
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cranial nerve reflex arc it's that's pertinent to that is the uh corneal reflex arc or the corneal reflex um for those who are trying to guess there's two uh reflex there's two cranial nerves involved and if you're listening to this maybe you can pause for a moment and test yourself to see if you know which two are involved
00:22:08
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Basically, what do we do with the corneal reflex?
00:22:11
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We take gauze and we touch or dab the cornea.
00:22:17
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The cornea is V1.
00:22:18
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It's the V1 branch of the fifth cranial nerve, trigeminal.
00:22:24
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And it goes in, that's the afferent arc.
00:22:27
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It goes into the pons, goes to the nucleus and comes back out.
00:22:32
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And what happens?
00:22:33
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The eye blinks.
00:22:34
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And that's the orbicularis oculi muscle controlled by seven.
00:22:39
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So you have a facial nerve involved as the efferent.
00:22:41
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So basically the corneal reflex is a great way to assess the integrity of the pons.
00:22:47
Speaker
Now, if you have something like a cerebellar hemorrhage or some sort of posterior fossa mass, it might be abutting the pons posteriorly.
00:22:57
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And so the first reflex to be lost in the scenario where you're having herniation from the
00:23:04
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posterior fossa and the cerebellum in particular might be the corneal reflex.
00:23:09
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So this is great if you know what the underlying pathology is you can spend more time on a very particular reflex arc and really hone in on your exam.
00:23:20
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A brief comment about the corneal reflex.
00:23:23
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Obviously this gold standard is taking gauze like a two by two or four by four and touching the cornea.
00:23:31
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Imagine if every resident, every medical student, every PA, every physician does that four times a day.
00:23:37
Speaker
Eventually you'll get corneal abrasions to the point where the patient, even if they recover, might not be able to see.
00:23:42
Speaker
And I have, I used to have a neurocritical care clinic where we would see patients after their stay and some of them would have corneal abrasions for this reason.
00:23:53
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So what I do personally
00:23:55
Speaker
is depending on how important it is to get a very accurate reflex.
00:24:00
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My first go-to is a poor man's corneal reflex.
00:24:03
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This is just a day-to-day check when you have no underlying pathology and you just want to get a good sense of the corneal reflex.
00:24:10
Speaker
I take my finger and I gently brush along the eyelashes and that elicits the same reflex.
00:24:17
Speaker
The patient will blink and that causes no damage whatsoever.
00:24:22
Speaker
Now, if you really wanted to get something a little bit more accurate but not cause abrasions, I take a saline syringe and about a foot or two above the patient, I'll just drop one drop of saline and the impact of the saline on the cornea creates the same effect.
00:24:43
Speaker
reflex but since it's just water or saline there's no long-term damage and you get your same uh blinking reflex any questions about that before i go to the medulla sergio no no i think that's an important point you made i mean of also being considered for the patient i never really thought about that but i can see especially in teaching institutions where they're done multiple times something to keep in mind so thanks for sharing that yeah and you know another thing i'll share um
00:25:12
Speaker
this is not quite brainstem related, but it's related to what I saw in this clinic.
00:25:18
Speaker
Patients would come to me in clinic and they lost and they didn't have nails.
00:25:23
Speaker
Their nails had fallen off.
00:25:25
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And when I looked into it, the nail bed pressure repeatedly,
00:25:32
Speaker
actually damaged the nail bed matrix.
00:25:34
Speaker
And not only did the nails fall off, but they couldn't grow them again, or they grew them, but it was like a deformed nail.
00:25:41
Speaker
So one of my mentors then told me you can get the same, you can elicit the same noxious response.
00:25:49
Speaker
If you know, this is hard to describe without showing you visually, but you apply pressure on
00:25:55
Speaker
on the outer lateral edge of the first metacarpal joint.
00:26:01
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That first bend right above your nail, instead of pushing it right on the top, squeeze with your nail on the side.
00:26:09
Speaker
Basically go away from the nail bed matrix.
00:26:12
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If you try it on yourself, it actually kind of hurts.
00:26:15
Speaker
And you can elicit the same noxious stimuli, but with no damage to the nail bed.
00:26:20
Speaker
That's just my personal recommendation.
00:26:22
Speaker
Perfect.
00:26:24
Speaker
Um, and so the last portion of the brainstem is the medulla, um, pause the recording here.
00:26:32
Speaker
If you want to guess which reflex arc, um, is involved in medulla.
00:26:37
Speaker
So the medulla, uh, we assess with nine and 10.
00:26:42
Speaker
So glossopharyngeal afferent and vagus efferent.
00:26:46
Speaker
And there's two ways of doing that.
00:26:47
Speaker
It's the cough and the gag reflex.
00:26:50
Speaker
You basically want to tickle the pharynx, um,
00:26:53
Speaker
either if they're intubated with the ballard of an ET tube, you go in line and that sort of tickles the upper trachea.
00:27:02
Speaker
Or if they're not, then you can just stick a tongue depressor and elicit the gag response.
00:27:08
Speaker
But either way, the afferent is that posterior trachea
00:27:12
Speaker
pharynx uh portion the sensory fibers there is the afferent and then the motor is this the the vagus nerve causing um the desire to to vomit or that that sort of gag response or a cough in the case of the cough reflex so that's the nine and ten and you do that and that gives you um the cough and reflex the cough and gag reflex a couple of things just briefly i will mention
00:27:40
Speaker
it is possible to lose the gag reflex with prolonged intubation.
Assessing Cerebellar Function in Sedated Patients
00:27:46
Speaker
And so it may not be the best way of assessing their medulla if you only do one.
00:27:54
Speaker
So I recommend a cough reflex and the gag reflex just to be extra confident.
00:27:59
Speaker
And the reason why you might check that in particular, this is not as common, but believe it or not, I've seen it quite a handful of times.
00:28:07
Speaker
is in someone with a lower cerebellar bleed,
00:28:13
Speaker
that is maybe they did a suboccipital cranium on and you're worried about upward herniation.
00:28:20
Speaker
That is a thing if you haven't heard of it, upward herniation.
00:28:23
Speaker
In particular, if there is an EBD in place where you might have slight negative pressure above the brainstem, right?
00:28:32
Speaker
Because the CSF is being evacuated from the top and pressure from the bottom with this cerebellar mass, the bleed or the tumor, whatever it is.
00:28:42
Speaker
And the first portion of the brainstem to go would be the cough and gag reflex or the medulla.
00:28:48
Speaker
But your midbrain might still be intact.
00:28:50
Speaker
Why?
00:28:51
Speaker
Because the pressure is coming from below, pushing up.
00:28:54
Speaker
And so this is a good way to think about assessing the brainstem.
00:28:58
Speaker
What portion of the brainstem are you most worried about?
00:29:00
Speaker
And spend time focusing on that particular reflex arc.
00:29:04
Speaker
Excellent.
00:29:05
Speaker
And I think obviously a lot of our listeners have done many of these examination and procedures, let's call them.
00:29:14
Speaker
But I think that putting it all together and linking it to the neuroanotomy and their clinical findings, I think, is ultimately what gives us a much better picture.
00:29:23
Speaker
And also I think it emphasizes the value that doing a good exam can have in our daily practice, right?
00:29:28
Speaker
Because you can find out things that
00:29:30
Speaker
That can help you mobilize appropriate treatment, but also choose the right next diagnostic test much more efficiently.
00:29:41
Speaker
Agreed.
00:29:42
Speaker
So before we go into more of the clinical application of a lot of this, I just wanted to know if there's any particular comments you want to make about anatomy and localization regarding the cerebellum, since we mentioned it a couple of times, and cerebellar bleeds obviously are something that a lot of our listeners will see.
00:30:03
Speaker
Yeah, that's a good point.
00:30:05
Speaker
To really appropriately assess the cerebellum,
00:30:09
Speaker
you really need engagement with the patient.
00:30:12
Speaker
And that's why it's so challenging to assess.
00:30:15
Speaker
Dysdiadokinesia is what we look for when you're doing rapid alternating movements.
00:30:23
Speaker
But you need the patient to be able to follow you by flipping their hands back and forth on their lap, for example.
00:30:30
Speaker
There are other tests.
00:30:32
Speaker
Finger-to-nose tests will help you assess dysmetria and whether they tend to overshoot or undershoot.
00:30:39
Speaker
That's hard when the patient is intubated and sedated.
00:30:43
Speaker
Even if they're intubated and you're lighting sedation, they're too out of it to reliably assess the cerebellum.
00:30:50
Speaker
So
00:30:51
Speaker
If I suspect cerebellar involvement, I'll watch their spontaneous movements.
00:30:57
Speaker
Obviously, lighten up sedation to the point where they're able to move.
00:31:00
Speaker
You'll notice that with large cerebellar strokes or cerebellar bleeds, you have very clumsy movements, almost like they're a little drunk.
00:31:10
Speaker
They're not accurate with holding cups.
00:31:14
Speaker
Maybe you could hold a cup in front of them and see if they reach towards it or a pen or something.
00:31:21
Speaker
You ask them to grab it.
00:31:21
Speaker
And as they're reaching, you notice there's a tremor, there's a sloppiness to their movement.
00:31:28
Speaker
It's not a straight shot.
00:31:29
Speaker
That's a great way of assessing the cerebellum.
00:31:31
Speaker
Just look at their spontaneous movements.
00:31:35
Speaker
You could also, if they're not intubated, take a look at their gait.
00:31:39
Speaker
And do they have a wide-based gait or a narrow-based gait?
00:31:43
Speaker
Obviously, this is not possible with most intubated patients.
00:31:48
Speaker
There are some who are intubated and walk.
00:31:51
Speaker
Those are amazing programs when PT is able to walk with intubated patients.
00:31:56
Speaker
But for the most part, I think it's hard to do.
00:32:01
Speaker
Excellent.
00:32:01
Speaker
I would like to maybe move more into the day-to-day clinical work that we do in the ICU and start talking more specifically of the exam in very specific situations.
Daily Neurological Exams in ICU
00:32:16
Speaker
So first, in a more broad context, what do you recommend, Adam, for our examination during our daily encounters and rounds or our daily visits to ICU patients?
00:32:29
Speaker
Yeah, this is really good.
00:32:31
Speaker
You know, it's kind of sad to say that we're so relatively advanced with our medical technology, and yet some of the most basic aspects, like the ABCD bundles, daily SATs, SBTs, that they don't really get done.
00:32:48
Speaker
Now, obviously, that varies institution to institution, but I would really, really, if there's
00:32:55
Speaker
Any say that you have as a listener to encourage very regular SATs and SBTs, I would say make sure you do it.
00:33:05
Speaker
A lot of people think that the SATs, SBTs are just for weaning assessment and whether they can be extubated.
00:33:13
Speaker
But really the SAT is also...
00:33:17
Speaker
for a neurological exam.
00:33:18
Speaker
It has to be done.
00:33:19
Speaker
It has to be done.
00:33:21
Speaker
It's terrible to find out that you haven't done an SAT for two or three days, only then to realize the patient had a large stroke.
00:33:30
Speaker
And it was an M1 occlusion that could have easily been removed with a thrombectomy.
00:33:35
Speaker
Or they had a bleed that we could have controlled by lowering the blood pressure and minimizing the extent of the bleed and stopping anticoagulation.
00:33:45
Speaker
It's happened more times than I care to say, and it's sad.
00:33:50
Speaker
And as a provider, we feel so bad for our patients.
00:33:55
Speaker
And so really the key is every day, at least once a day, ideally once a shift, every 12 hours, we lighten up the sedation just enough to get a good basic neuro exam and ensure that no changes have been made and there's no changes to the neuro exam from a day-to-day basis.
00:34:13
Speaker
When you approach that bedside, Adam, did you have like a framework that you follow?
00:34:19
Speaker
Yeah, I usually go top down.
00:34:25
Speaker
And what I mean by that is the standard international neuro exam.
00:34:34
Speaker
This is across the board in all countries.
00:34:37
Speaker
Well, and this was initially created way back when by the French neurologists, you know, Babinski and Charcot and all of those folks 100 plus years ago, they needed some sort of standardization of how you approach a neurological patient.
00:34:53
Speaker
And they came up together and decided, OK, we're going to do it this way.
00:34:57
Speaker
And so this is the standardized neuro exam.
00:34:59
Speaker
You start with mental status.
00:35:02
Speaker
Then you go to cranial nerves.
00:35:05
Speaker
Then you deal with motor.
00:35:07
Speaker
function, reflexes, sensory function, and then gait and balance.
00:35:13
Speaker
That is an international standard of approaching the neuro exam.
00:35:18
Speaker
Now we have to modify this a little bit for the ICU patient, and I'll share with you how we do that.
00:35:23
Speaker
The first is a mental status exam.
00:35:25
Speaker
there are just as you see in the Glasgow Como scale, the GCS scale, there are different ways that you want to assess it.
00:35:33
Speaker
So first what I'll do, assuming that they are, they've been off sedation for several hours, uh, like off propofol and fentanyl or whatever your institution uses, you approach the patient and you notice, do they, do they recognize that there's someone entering the room?
00:35:49
Speaker
That would be equivalent to a spontaneous eye opening, right?
00:35:53
Speaker
Or,
00:35:54
Speaker
Do they open their eyes when you say their name?
00:35:56
Speaker
And you don't have to scream.
00:35:58
Speaker
You just say, hey, Mr. Johnson or so-and-so.
00:36:00
Speaker
Can they respond to voice?
00:36:05
Speaker
Next, if they don't respond, I'll gently touch them.
00:36:09
Speaker
Do they respond to tactile stimuli?
00:36:11
Speaker
Maybe a gentle shake on their shoulder or something like that.
00:36:15
Speaker
Too often I see eager...
00:36:17
Speaker
students going right up to the patient and cranking on their finger and providing pain.
00:36:24
Speaker
Maybe they could have responded with less stimulation.
00:36:28
Speaker
And it's important to know that they did not respond to verbal and tactile stimuli, but only to noxious.
00:36:33
Speaker
That's a good thing to know.
00:36:36
Speaker
So after pain, then, sorry, after tactile stimulation, then you apply pain.
00:36:42
Speaker
And that's, this is a whole other topic, but where you apply pain gives you a lot of indication of what the patient can do.
00:36:50
Speaker
Do you apply it first?
00:36:53
Speaker
I guess there's a lot of things to say, but in terms of applying pain, don't forget your diabetic patients.
00:36:58
Speaker
If you're providing peripheral nervous stimuli, like on your toes or your fingertips,
00:37:05
Speaker
their lack of response may not indicate a problem with their mental status, but rather because they have severe neuropathy.
00:37:12
Speaker
So then in that case, move proximally and pinch inside their elbow or inside their knees or provide a supra above the neck pain, like a superior orbital ridge pain or a temporal mandibular joint pain, TMJ.
00:37:30
Speaker
So,
00:37:31
Speaker
That's the first thing is mental status.
00:37:33
Speaker
What is their mental status?
00:37:34
Speaker
Then I go to the cranial nurse.
00:37:36
Speaker
And if they're intubated, for example, I'll just put the ballard of the ET tube down, see if they cough.
00:37:42
Speaker
I'll look at their eyes, shine light.
00:37:44
Speaker
It's best to do that in a dark setting.
00:37:47
Speaker
So tell the nurses to close the lights and then flash the light.
00:37:53
Speaker
and then you do the corneal test.
00:37:56
Speaker
And like I told you with the poor man's corneal or the saline, that's all you need to assess that.
00:38:01
Speaker
So first is mental status, cratal nerves, then motor and sensory.
00:38:05
Speaker
Now for the intubated critical care patient, you can assess both simultaneously in providing slight noxious stimuli.
00:38:16
Speaker
If you pinch their finger and they withdraw,
00:38:21
Speaker
Not only does it tell you that they have a motor function of their arms, for example, but they also felt it.
00:38:27
Speaker
So the motor and sensory go together and then you do the same thing with the, with the legs.
00:38:32
Speaker
And if they don't respond, move proximally again, for the same reason of, of potential peripheral neuropathy.
00:38:39
Speaker
And that covers the motor and sensory.
00:38:41
Speaker
Now you don't need to always provide noxious pain.
00:38:45
Speaker
Talk to them, see if they follow commands.
00:38:48
Speaker
If they're able to lift up all four extremities, that's a great way of assessing the motor function without having to provide pain.
00:38:57
Speaker
And the very last thing I often defer because I can't assess their gait or their balance for obvious reasons.
00:39:04
Speaker
And one last thing, Sergio, that I'll say about the bedside neuro exam in the ICU, it's...
00:39:12
Speaker
I've also seen people get hung up on the MRC scale, which is the 2+, 3+, 4- out of 5 strength.
00:39:23
Speaker
In my experience, a lot of people get lost with the numbers.
00:39:28
Speaker
Yes, it's appropriate, and I'm sure there's a neurologist out there listening to me right now that's going to get upset.
00:39:34
Speaker
Yes, those are good numbers to use.
00:39:37
Speaker
but I find it so much more helpful if you write out verbally what they did.
00:39:43
Speaker
The patient had movement against gravity.
00:39:46
Speaker
The patient was able to lift their limbs off the bed for five seconds.
00:39:52
Speaker
The patient was able to lift and hold against resistance.
00:39:58
Speaker
All of those things equate to a level two, three, or four respectively, but when you say it verbally in your note, it makes so much more sense
00:40:06
Speaker
for those who may not understand the scale like nurses for example or or trainees it you could put both but my recommendation is it just is a couple more words but it makes a lot more sense especially if you're signing off and the next provider takes on they can see oh the patient was able to lift against gravity and now they can't okay something's different something's new
00:40:30
Speaker
Adam, you did mention the Medical Research Council score, the MRC.
00:40:34
Speaker
Are there any other objective tools without going into much detail that would be applicable for the ICU and that our listeners should look into?
00:40:44
Speaker
Yeah.
00:40:45
Speaker
So we talked a little bit about the Glasgow Coma Scale GCS.
00:40:48
Speaker
That's super helpful.
00:40:50
Speaker
Of course, more so up front when the patient first comes in.
00:40:55
Speaker
A correlate to that or something similar may be the four score.
00:40:59
Speaker
Now the four score is
00:41:02
Speaker
arguably more accurate than the GCS, but it does take a little bit more time to do.
00:41:08
Speaker
It's a grade of, it stands for Full Outline of Unresponsiveness Score, or four, and it grades the coma severity.
00:41:17
Speaker
It was developed by Ilko Vedic from Minnesota, and it can be out of 16 points.
00:41:26
Speaker
So it's very similar to the Glasgow Coma Scale, but it's essentially looking at eye response, motor response, brainstem reflex, and respiration pattern.
00:41:33
Speaker
That's what sets it apart from the GCS.
00:41:36
Speaker
And the last score I'll mention pertinent to most daily usage is the CAM ICU.
00:41:43
Speaker
And I actually really recommend this.
00:41:45
Speaker
I think the CAM ICU score is quite important.
00:41:49
Speaker
It's the ability to detect delirium in the ICU setting.
00:41:55
Speaker
I highly recommend all institutions educate their nurses and providers in assessing using CAM-ICU and interpreting CAM-ICU because ICU delirium has
00:42:08
Speaker
very negative long-term impacts on the patient's quality of life when they leave the ICU.
00:42:15
Speaker
And it's something that is preventable.
00:42:17
Speaker
We have a slew of identifiable factors, variables that we can impact and change and prevent or mitigate
00:42:28
Speaker
ICU delirium.
00:42:30
Speaker
But in order to do that, we need to know first if they are developing ICU delirium before it gets to the crazy, wacky, hyperactive delirium stage.
00:42:39
Speaker
We can start to pick it up by the CAM ICU score.
00:42:46
Speaker
You did mention a little bit about patients in coma, and that would be, I guess, a separate category than our daily evaluations of sedated patients.
Conducting Coma Examinations
00:42:54
Speaker
So when we know somebody or suspect somebody is in real coma, how do you approach that exam, and what could you tell us in terms of pros and pitfalls?
00:43:06
Speaker
Yeah.
00:43:07
Speaker
So I...
00:43:09
Speaker
mentally, you know, we all have mental heuristics and, um, we got files in our head about how to structure things.
00:43:18
Speaker
I put coma very closely together with a brain death exam.
00:43:22
Speaker
Um, cause they're, they're very similar and they're similar in the sense that my focus tends to be a little bit more on the brain stem because by the very definition, when someone's in a coma, there's no obvious
00:43:39
Speaker
cortical function.
00:43:39
Speaker
They're not engaging with you, talking with you.
00:43:41
Speaker
You can't assess their language.
00:43:43
Speaker
You can't assess their personality and those, these sorts of things.
00:43:46
Speaker
Uh, so what you're dealing with is you're dealing with primitive movements and primitive reflexes.
00:43:52
Speaker
So I'll actually pay a lot more attention on the brainstem.
00:43:56
Speaker
Um, really make sure that the reflex arcs I'm looking at, uh, make sense.
00:44:03
Speaker
And I'll spend a little bit more time on the reflexes and the reflexes.
00:44:10
Speaker
I mean, the DTRs, deep tendon reflexes and the primitive reflexes such as Babinski and triple flexion, because when changes occur, when someone's in a coma, they occur automatically.
00:44:24
Speaker
in that regard, you don't see, obviously if they wake up and they converse, that's great.
00:44:29
Speaker
But when there are changes to the neuro exam, it's usually subtle changes, uh, with deep, deep tendon reflexes with, um, uh, Babinski triple flexion and the brainstem reflexes.
00:44:43
Speaker
And there's a, uh, something I want to, this might go here.
00:44:47
Speaker
It might go in the brain death exam, uh, topic, but I want to point out when people,
00:44:55
Speaker
elicit deep tendon reflexes, it's good to touch and hold.
00:45:03
Speaker
And what I mean by that is put your finger on the tendon that you're testing.
00:45:07
Speaker
And when you tap, tap on top of your finger,
00:45:11
Speaker
And the pressure will translate to the tendon.
00:45:14
Speaker
Why?
00:45:15
Speaker
Because you're more likely to feel a muscular contraction than you are to see one, especially if someone's been sedated for a long time.
00:45:22
Speaker
Your reflexes might be blunted.
00:45:24
Speaker
So you can feel the reflex before you see it.
00:45:27
Speaker
And so when I teach, I often recommend put your fingers where the tendon are and then tap the top of your fingers.
00:45:34
Speaker
You'll feel the reflex before you see it.
00:45:38
Speaker
And the other thing I'll say in terms of Babinski, eliciting Babinski, you can elicit it with noxious stimuli.
00:45:47
Speaker
You don't have to do the classic, you know, striking up the sole of the foot.
00:45:53
Speaker
That's obviously the classic way.
00:45:55
Speaker
There's different ways of eliciting it.
00:45:57
Speaker
But if you are going to pinch something, pinch the lateral toes.
00:46:02
Speaker
Like the pinky, for example, or one of the smaller toes.
00:46:06
Speaker
Why?
00:46:07
Speaker
Because you're looking at the big toe.
00:46:10
Speaker
You're looking to see if the big toe moves up or down.
00:46:13
Speaker
So if you're pinching the big toe and you're holding it, you can't see what it's doing because your hand's on it.
00:46:19
Speaker
And that's a common mistake that I see people do.
00:46:23
Speaker
So pinch the lateral toes.
00:46:25
Speaker
So I would say in the coma exam, I focus on the brainstem, the reflexes and these sort of stereotype movements like the Babinski or triple flexion.
00:46:34
Speaker
Can you just give us a simple interpretation, remind us of how to interpret the Babinski?
00:46:41
Speaker
Sure.
00:46:42
Speaker
So the Babinski, actually a brief aside, if we have the time, there's a great story.
00:46:49
Speaker
of how Babinski, I think his name was Joseph, Joseph Babinski.
00:46:55
Speaker
I could be wrong about that.
00:46:57
Speaker
He was in a Paris hospital, Salpetriere, and it was a hospital for the homeless and sort of psychiatric patients.
00:47:09
Speaker
And the nurses had this tendency of tucking the patients in at night really tightly.
00:47:15
Speaker
Like the bed sheets were super, super tight.
00:47:18
Speaker
And in the morning, they would pull the bedsheets off and the act of pulling the bedsheets had the bedsheets slide over the bottom of the feet because it was so tight.
00:47:29
Speaker
And for patients who had CNS lesions, Babinski noticed that their toes would go up whenever the nurses pulled the bedsheets off for him to do his exam.
00:47:38
Speaker
And he wondered what was going on and he tried to elicit the same action by sliding something along the bottom of the sole.
00:47:45
Speaker
And that led to his...
00:47:47
Speaker
classic method now of stroking the sole of the foot.
00:47:50
Speaker
So I just thought that was an interesting historical lesson.
00:47:54
Speaker
But to answer your question, a toe going up is bad.
00:48:00
Speaker
A toe going down is good.
00:48:03
Speaker
We want to see.
00:48:03
Speaker
And the only case where that's acceptable as normal is in a baby.
00:48:12
Speaker
because they haven't fully formed all of their nervous system.
00:48:15
Speaker
And so you'll see that the classic up-going toe with fanning of the other toes in very, very young babies.
00:48:22
Speaker
But if you see it in adult, the up-going toe and the fanning, that is not good.
00:48:28
Speaker
And also one additional aside,
00:48:32
Speaker
It's confusing when you say positive Babinski or negative Babinski or because no one really knows what you're talking about.
00:48:39
Speaker
Are you saying it's positive and that it's not not pathological?
00:48:42
Speaker
Or are you saying it's it's negative because it is pathological?
00:48:45
Speaker
So just describe what you're seeing.
00:48:48
Speaker
up going toe or down going toe and that's and that's it you don't even have to mention babinski or his name it's just my personal recommendation because then people can see your note and say oh yeah up going toe that's bad we know that's bad and what's the neural axis explanation of the up going toe yeah actually it's really good and maybe it relates to some brain death testing um when
00:49:17
Speaker
When you stimulate the toe, the afferent fiber, the sensory fiber, goes all the way up the leg and it arcs into the spinal cord.
00:49:26
Speaker
Now, normally in a healthy patient, there is tonic suppressive activity from the brain that suppresses the reflex arc.
00:49:39
Speaker
That normally should happen.
00:49:42
Speaker
When you have a CNS lesion or either in the brain or the spinal cord,
00:49:47
Speaker
that tonic suppression from above isn't there anymore.
00:49:52
Speaker
And so what happens is that afferent arc comes all the way to the spinal cord,
00:49:56
Speaker
It arcs on another interneuron and then goes back down the leg and causes the toe to go up or in the case of triple flexion, the toe to go up, you get dorsiflexion, flexion of the knee and flexion of the hip.
00:50:09
Speaker
That's why it's called triple flexion.
00:50:12
Speaker
Foot, knee and hip.
00:50:13
Speaker
Those are the three areas that flex.
00:50:16
Speaker
Normally that doesn't happen because there's no, there's no arc because the brain is suppressing that reflex.
00:50:26
Speaker
Excellent.
00:50:26
Speaker
And we did talk a little bit about evaluation of potential death by neurologic criteria.
Brain Death Evaluation
00:50:33
Speaker
So why don't we go into that topic as our last category of the neuro exam in evaluating brain death and tell us how do you think about this, what we should look for, how you organize it, and again, if you can share any common pitfalls and pros.
00:50:51
Speaker
Yeah, this is great.
00:50:52
Speaker
Really, really good.
00:50:55
Speaker
I won't go into the whole brain death evaluation because every hospital has their protocol sheet, which you should look into and familiarize yourself with.
00:51:03
Speaker
Um, and obviously the apnea test has its own role.
00:51:08
Speaker
And so I'll, we won't talk about that here, but in terms of the actual clinical exam, when you're, when you're assessing the way I do it is I imagine a U and what I mean by that is you sort of draw from one ear,
00:51:24
Speaker
down the patient's body and then back up to the other ear that creates the letter u if you will and that that's sort of my circuit that's the pathway i take as i examine and i'll walk walk you through it so first is you try to like i said you you start with the mental status to try to elicit to see if they if they respond to to voice touch and noxious stimuli and classically they won't but i will do a super orbital ridge
00:51:54
Speaker
pain, I will then do TMJ pain.
00:51:57
Speaker
And then that helps me assess, do they respond to noxious, central noxious stimuli?
00:52:04
Speaker
And then let's say they don't.
00:52:05
Speaker
Okay, that's that.
00:52:06
Speaker
Next, I go through my cranial nerves.
00:52:11
Speaker
I will then assess the brainstem exactly like I told you.
00:52:14
Speaker
I'll shine light in their eyes.
00:52:16
Speaker
That's the pupillary reflex.
00:52:18
Speaker
I will then look to see if they have coronal reflex.
00:52:20
Speaker
And for this situation, I always, always use a gauze.
00:52:24
Speaker
Do the gold standard.
00:52:25
Speaker
When you're assessing brain death, do it properly, fully.
00:52:28
Speaker
So I use a gauze.
00:52:30
Speaker
And I don't swipe across the cornea.
00:52:33
Speaker
I just, I just touch, just poke like a little dab.
00:52:36
Speaker
That's all you need to elicit the response.
00:52:39
Speaker
And then I'll use the ET tube Ballard.
00:52:42
Speaker
Um, and I will try to elicit the cough and the gag that assesses the brainstem for me.
00:52:48
Speaker
And then you have, um, if their neck is intact, you could do the oculosephalic test.
00:52:55
Speaker
That's the doll's eye.
00:52:57
Speaker
That said, this is a technical issue, but the oculocephalic reflex falls under the category of a vestibular ocular reflex, VOR.
00:53:09
Speaker
The oculocephalic reflex, DALSI, is a type of vestibular ocular reflex.
00:53:15
Speaker
The classic way of testing the vestibular ocular reflex, VOR, is with cold caloric.
00:53:21
Speaker
So you don't actually need to do DALSI, but I think a lot of people do it.
00:53:26
Speaker
And that's fine.
00:53:26
Speaker
But you're assessing the VORs with cold calorics.
00:53:30
Speaker
Now, at this point, after I've done the brainstem, I do cold calorics.
00:53:34
Speaker
I have a bin with ice water.
00:53:37
Speaker
I have a 50 or 60 cc syringe.
00:53:40
Speaker
And what personally what I like to do and how I was taught is you want the water, the ice water to go right up against the tympanic membrane.
00:53:50
Speaker
So I'll typically use a sort of a small syringe that has a lure lock at the end that I could secure to the 50cc syringe with a little bit of tubing.
00:54:01
Speaker
That's probably the length of my pinky.
00:54:03
Speaker
And I insert that tubing into the ear, secure it to the lure lock end of the syringe, and I do a 30-second power
00:54:13
Speaker
flush of that ice water up against the tympanic membrane.
00:54:17
Speaker
Now, ideally, if this is a patient that came in as a trauma, you should always use an otoscope to make sure you don't have a perforated tympanic membrane before you do this.
00:54:27
Speaker
But assuming the tympanic membrane is intact, you do that 30 second power flush.
00:54:32
Speaker
Now, here's something I think is really important that I've seen done wrong several times.
00:54:39
Speaker
When you're power flushing the ice water,
00:54:42
Speaker
You could have either yourself or a helper lift up the eyelids of the patient.
00:54:48
Speaker
A lot of people are taught the mnemonic COWS, cold opposite warm same.
00:54:53
Speaker
What we don't remember is that that mnemonic refers to the corrective saccade.
00:54:59
Speaker
The tonic movement that you're expecting to see is that the eyes move towards the cold.
00:55:08
Speaker
and then the brain tries to correct it by going away.
00:55:12
Speaker
So the mnemonic cows refers to the correction of the tonic movement.
00:55:17
Speaker
So what you should see is the eyes slowly move towards the cold.
00:55:22
Speaker
And the other thing that I think people don't realize is that movement does not happen instantaneously.
00:55:30
Speaker
The average time it takes, I bet most people don't know this, the average time it takes for
00:55:34
Speaker
for the eyes to move towards a cold stimulus is about 30 seconds.
00:55:39
Speaker
And that's a long time.
00:55:42
Speaker
So that's why I always count.
00:55:44
Speaker
I do a full 60 seconds in my assessment.
00:55:47
Speaker
You do the power flush, hold open the eyes, and you have to look at a clock or have someone count for you.
00:55:54
Speaker
wait fully 60 seconds because it takes time for the temperature to translate to the inner ear and the semicircular canals.
00:56:05
Speaker
Before I go further, Sergio, any thoughts, any questions?
00:56:08
Speaker
I think that those are important points because I think both the doll's eyes and the octocephalic are often misinterpreted by people, but often the procedure is not followed as it should.
00:56:21
Speaker
And then, I mean, obviously the validity is going to be questionable.
00:56:26
Speaker
Yeah, exactly.
00:56:27
Speaker
And it's fine to do both, but make sure you know what you're looking for when you do it.
00:56:33
Speaker
So,
00:56:34
Speaker
The other mistake that I see with cold caloric is people will go immediately from one side to the next.
00:56:42
Speaker
Now, really what's happening here is when you're inducing cold on one ear, the brain interprets, the brain causes the eyes to move because it senses a temperature differential between the two inner ears.
00:56:58
Speaker
If you go straight from one ear to the other,
00:57:02
Speaker
the inner ears haven't had time to re-equilibrate and go back to room temperature.
00:57:07
Speaker
So then you're not really testing temperature differential because now you're dealing with one cold inner ear and immediately creating another cold inner ear.
00:57:15
Speaker
And so then they're both cold.
00:57:17
Speaker
So that's why I do the U method.
00:57:20
Speaker
I start with one ear and then after I do a cold caloric on one side, I then move down to the arm and I try to elicit noxious stimuli to the arm.
00:57:31
Speaker
And then I go down to that same side leg.
00:57:35
Speaker
I try to get the Babinski response, triple flexion.
00:57:37
Speaker
I look for spinal reflexes.
00:57:39
Speaker
I then go to the other leg.
00:57:42
Speaker
And now I'm going back up the U-shape to the other arm, the contralateral arm.
00:57:49
Speaker
Again, assessing for noxious stimuli, both peripherally and proximally in case they have neuropathy.
00:57:55
Speaker
And then finally, after that, presumably that takes about two to three minutes to do properly.
00:58:02
Speaker
You're now up.
00:58:03
Speaker
to the other ear where you can then do cold calorics again.
00:58:06
Speaker
And by that time, the temperature has gone back to normal.
00:58:10
Speaker
And when you elicit the final cold caloric, you know you're doing it properly.
00:58:14
Speaker
So that would complete my brain death exam.
00:58:18
Speaker
Excellent.
00:58:19
Speaker
And we'll link it in the show notes, our recent episode on determination of neurological death, just for more references for the other parts of the brain death evaluation that do not include the physical exam.
00:58:33
Speaker
Adam, a wonderful discussion.
00:58:35
Speaker
I think a lot of very, very useful pearls that we can apply at the bedside that can help us be better clinicians, which is ultimately what we try to achieve through the podcast.
Kindness in Critical Care and Closing Thoughts
00:58:47
Speaker
We have a
00:58:48
Speaker
a tradition of finishing the podcast with a couple of questions that are unrelated to the clinical topic.
00:58:54
Speaker
Would that be okay?
00:58:55
Speaker
Yeah, absolutely.
00:58:56
Speaker
Let's do it.
00:58:57
Speaker
So the first question relates to books.
00:58:59
Speaker
What book or books have influenced you the most or what book have you given as a gift most often to others?
00:59:07
Speaker
You know, I thought a lot about this when you told me about this potential question.
00:59:14
Speaker
I have so many books that I could recommend, Sergio, but I just felt for our audience and listeners to recommend Meditations by Marcus Aurelius.
00:59:24
Speaker
The reason why I like this book, one, I've read it repeatedly over and over again.
00:59:28
Speaker
My book is worn out at this point.
00:59:31
Speaker
But this is arguably the most powerful man in the history of Earth, a Roman emperor.
00:59:40
Speaker
And he wrote this book, this is his personal journal, with no intention of anyone ever seeing this, ever.
00:59:47
Speaker
This is truly raw emotions and raw thoughts from someone who was not writing this to have it be published ever.
00:59:56
Speaker
And reading what he talks about, I'm just so impressed, but also moved and inspired by the way he approaches things.
01:00:07
Speaker
I'll just share one quote in here because it's something that I recently read that was impactful.
01:00:13
Speaker
I'll just read a quote here if that's all right.
01:00:17
Speaker
People try to get away from it all, to the country, to the beach, to the mountains.
01:00:22
Speaker
You always wish that you could too, which is idiotic.
01:00:26
Speaker
You can get away from it any time you like by going within.
01:00:32
Speaker
know where you go is more peaceful more free of interruption than your own soul especially if you have other things to rely on an instance recollection and there it is complete tranquility and by tranquility i mean a kind of harmony and i really like that quote because this famous adage of wherever you go there you are if you think that taking a trip to you know italy or the beach or something is going to take away all your worries
01:00:59
Speaker
It won't.
01:01:00
Speaker
There's nothing about the external circumstance that's going to dramatically change your mood or your perception of things.
01:01:06
Speaker
You have to go within and deal with what's coming up within.
01:01:10
Speaker
And that's, I think, a great lesson for all of us, no matter what our philosophical persuasion.
01:01:16
Speaker
I think it's obviously a phenomenal recommendation.
01:01:19
Speaker
Those runners who know me know that this is one of my favorite books.
01:01:23
Speaker
And I think what he refers to also as the inner citadel or the inner fortress, right?
01:01:29
Speaker
To cultivate that strength within is ultimately what I think determines how we live.
01:01:36
Speaker
And obviously very applicable to what we do every day in the ICU, but just applicable to
01:01:40
Speaker
to any walk of life.
01:01:41
Speaker
So we'll definitely put a link.
01:01:43
Speaker
And for those of you who have not given it a try, highly recommend it.
01:01:48
Speaker
Thanks for sharing that.
01:01:49
Speaker
Really, really awesome.
01:01:51
Speaker
My second question, Adam, is if you could share with us something you have changed your mind about over the last couple of few years.
01:01:58
Speaker
That's a really good question.
01:02:00
Speaker
I got to commend you, Sergio.
01:02:01
Speaker
These questions are fantastic.
01:02:03
Speaker
One of the things that I've changed my mind about that I'm still...
01:02:10
Speaker
developing is the need to talk.
01:02:15
Speaker
And what I mean by that is we often as intensivists go to a patient's family, we're sitting down, we have a goals of care conversation, or maybe we're just having a daily update and the family's sitting by the bedside.
01:02:32
Speaker
Yes, it's important to say your piece and to give the update and to educate and explain, but more importantly,
01:02:40
Speaker
Often than not, it's being quiet, letting them express themselves and being comfortable with silence that creates more healing than you know.
01:02:53
Speaker
I've had moments where the patients, you know, their family would say, why is this happening?
01:02:58
Speaker
Why is this happening to us?
01:03:01
Speaker
You know, these are questions that don't need a response.
01:03:05
Speaker
And so nowadays, what I tend to go to is I hear them.
01:03:10
Speaker
And I just keep my mouth closed.
01:03:13
Speaker
And there's a palpable feeling of we're all processing this together in silence.
01:03:19
Speaker
And silence doesn't need to be filled with words.
01:03:22
Speaker
It can just be.
01:03:23
Speaker
So I'm learning to become more and more comfortable with silence and just being with family members.
01:03:30
Speaker
I feel like there's way more healing that happens there than with the words.
01:03:35
Speaker
And the final question is, what would you want every intensivist who's listening to us to know could be a quote, a fact, or just a thought?
01:03:45
Speaker
Yeah, I guess it's related to the above.
01:03:49
Speaker
But it sounds so cliche now that I'm saying it right now, but I really, having worked at now five, six hospitals, I can't recall exactly the value of kindness itself.
01:04:04
Speaker
I cannot overemphasize the role and impact that kindness can have.
01:04:11
Speaker
There's so many reasons for us to get upset in the ICU, but the nurses, the RTs, the staff, the ancillary staff, janitors, social workers, case managers, we're all a big family and we're working with each other very, very often.
01:04:28
Speaker
And so daily kindness is,
01:04:31
Speaker
goes a really long way.
01:04:32
Speaker
And for all we know, everyone's dealing with a hard battle that we're just not even privy to.
01:04:39
Speaker
And the brief moments of respite when a clinician is kind to you can have a very long-term positive impact.
01:04:46
Speaker
And so I highly recommend taking a moment and just to be as kind as possible every day.
01:04:54
Speaker
And since you mentioned meditations from Marcos Aurelius, he writes in meditations as a reminder to himself, being like you said, the most powerful person on earth at that point probably, that it's not enough to be right.
01:05:08
Speaker
You must also be kind.
01:05:10
Speaker
And I think this is a great lesson for our clinicians, right?
01:05:12
Speaker
I mean, even if you are right about something, it doesn't excuse you from saying why you're right and what needs to be done in a very kind way.
01:05:21
Speaker
So I think that's a...
01:05:22
Speaker
Perfect place to stop.
01:05:25
Speaker
Adam, I want to thank you for sharing your expertise and your time with us and hope to have you back on the podcast soon.
01:05:32
Speaker
Likewise.
01:05:33
Speaker
Thank you, Sergio.
01:05:36
Speaker
Thank you for listening to Critical Matters, a sound podcast.
01:05:40
Speaker
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01:05:46
Speaker
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01:05:50
Speaker
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