WEBVTT 00:00:07.880 --> 00:00:10.759 You're in the bay. Once you get over to the bed, 00:00:10.919 --> 00:00:13.560 we'll give you the story. Everything's going 00:00:13.560 --> 00:00:17.339 to happen super fast. Welcome to the emergency 00:00:17.339 --> 00:00:43.320 room. You know usually when we talk about a medical 00:00:43.320 --> 00:00:45.780 diagnosis, there's this I mean, there's this 00:00:45.780 --> 00:00:48.640 expectation of precision. It's almost like engineering. 00:00:48.820 --> 00:00:51.159 Right. It's very binary, structural. Exactly. 00:00:51.359 --> 00:00:54.500 Like, you break your arm, you go to the ER, the 00:00:54.500 --> 00:00:57.039 x -ray shows that jagged white line through the 00:00:57.039 --> 00:00:58.939 radius, and the doctor just points at the screen 00:00:58.939 --> 00:01:01.539 and says, you know, there it is. That's the problem. 00:01:02.159 --> 00:01:03.899 And that's comforting, honestly. We like things 00:01:03.899 --> 00:01:06.549 to be visible. Totally. We like them to be categorized 00:01:06.549 --> 00:01:08.469 so we can just, you know, put a cast on it and 00:01:08.469 --> 00:01:10.629 move on. But then you step into the world of 00:01:10.629 --> 00:01:13.569 neurocritical care. Oh, man. Yeah. You step into 00:01:13.569 --> 00:01:16.109 intracranial regulation, traumatic brain injury, 00:01:16.269 --> 00:01:19.829 neuro infections, and suddenly that metaphorical 00:01:19.829 --> 00:01:22.930 X -ray machine is just totally broken. We're 00:01:22.930 --> 00:01:26.090 looking at a diagnostic landscape that is entirely 00:01:26.090 --> 00:01:28.790 murky. It really is. The brain is basically this 00:01:28.790 --> 00:01:32.150 black box locked inside a rigid, unforgiving 00:01:32.150 --> 00:01:34.659 vault. Right. And the terrifying part is that 00:01:34.659 --> 00:01:37.219 when things go wrong inside that vault the signs 00:01:37.219 --> 00:01:41.159 are so incredibly subtle for hours or even days 00:01:41.159 --> 00:01:43.439 until they are suddenly just catastrophically 00:01:43.439 --> 00:01:46.579 obvious. And by the time they are obvious it's 00:01:46.579 --> 00:01:48.980 often too late to reverse the damage. Right, 00:01:49.140 --> 00:01:51.079 which is exactly why we're doing this deep dive. 00:01:51.319 --> 00:01:54.040 Today we are speaking directly to you, the dedicated 00:01:54.040 --> 00:01:56.780 ICU nurse looking to elevate your practice from 00:01:56.780 --> 00:01:59.719 just being competent at the bedside to truly 00:01:59.719 --> 00:02:02.459 thinking like an elite intensivist. We're going 00:02:02.459 --> 00:02:05.459 to aggressively apply the 80 -20 Pareto principle 00:02:05.459 --> 00:02:08.460 here. Meaning we are going to extract that 20 00:02:08.460 --> 00:02:11.539 % of critical high -yield pathophysiology and 00:02:11.539 --> 00:02:14.539 clinical reasoning that dictates 80 % of your 00:02:14.539 --> 00:02:17.500 bedside outcomes. Exactly. We want to transform 00:02:17.500 --> 00:02:19.300 the foundational facts you learned in nursing 00:02:19.300 --> 00:02:22.740 school into immediate life -saving pattern recognition. 00:02:23.180 --> 00:02:26.240 Because in the ICU, your patient's brain cannot 00:02:26.240 --> 00:02:28.840 advocate for itself. Right. The monitor might 00:02:28.840 --> 00:02:30.780 beep, but it doesn't give you the context. It 00:02:30.780 --> 00:02:32.819 relies entirely on your ability to translate 00:02:32.819 --> 00:02:35.659 a subtle sluggishness in a pupil or a light shift 00:02:35.659 --> 00:02:38.500 into pressure waves into action before the catastrophic 00:02:38.500 --> 00:02:41.180 signs ever appear. So I am thrilled to be here 00:02:41.180 --> 00:02:44.219 to connect that cellular pathophysiology directly 00:02:44.219 --> 00:02:47.360 to your moment -by -moment nursing actions. You, 00:02:47.419 --> 00:02:49.659 the listener, are the critical third member of 00:02:49.659 --> 00:02:51.979 our rounding team today. We're gonna go deep 00:02:51.979 --> 00:02:54.379 into the mechanics of a failing brain step -by 00:02:54.379 --> 00:02:57.080 -step. Let's do it. I'm coming at this as a fellow 00:02:57.080 --> 00:02:59.819 lifelong learner ready to ask the questions and 00:02:59.819 --> 00:03:01.740 sometimes get confused so we can really get to 00:03:01.740 --> 00:03:03.759 the bottom of this. Let's start with the absolute 00:03:03.759 --> 00:03:06.569 foundation. intracranial regulation and increased 00:03:06.569 --> 00:03:09.590 ICP. Before we can fix a broken brain, we have 00:03:09.590 --> 00:03:11.750 to understand how a normal brain protects itself. 00:03:12.090 --> 00:03:14.750 So if we look at the 80 -20 of this, why does 00:03:14.750 --> 00:03:18.289 intracranial pressure or ICP matter so brutally 00:03:18.289 --> 00:03:20.949 much? It matters for one very simple reason. 00:03:21.430 --> 00:03:23.930 Sustained pressure kills tissue. The skull is 00:03:23.930 --> 00:03:26.889 a closed box. Normal ICP is usually between 5 00:03:26.889 --> 00:03:29.250 and 15 millimeters of mercury. Okay, 5 to 15. 00:03:29.270 --> 00:03:31.870 Right. A sustained ICP of greater than 20 millimeters 00:03:31.870 --> 00:03:34.009 of mercury will crush and kill brain tissue. 00:03:34.159 --> 00:03:37.960 Period. Anyone with a new mass, bleeding, cellular 00:03:37.960 --> 00:03:40.520 swelling, or a backup of cerebrospinal fluid 00:03:40.520 --> 00:03:43.900 is at immediate risk. Okay, so the must -know 00:03:43.900 --> 00:03:46.639 facts for this foundation. I always think of 00:03:46.639 --> 00:03:48.919 the Monroe Kelly doctrine like a strictly packed 00:03:48.919 --> 00:03:51.240 suitcase. I love that analogy. Yeah. Let's say 00:03:51.240 --> 00:03:53.319 you've packed it perfectly for a two -week vacation. 00:03:53.800 --> 00:03:56.840 It is zipped tight. Inside the suitcase, you 00:03:56.840 --> 00:03:59.840 have exactly three things. You've got 78 % brain 00:03:59.840 --> 00:04:04.580 tissue, 12 % intravascular blood, and 10 % cerebrospinal 00:04:04.580 --> 00:04:08.289 fluid, or CSF. Right. And the suitcase has absolutely 00:04:08.289 --> 00:04:11.409 no give. It's hard plastic. Exactly. So if you 00:04:11.409 --> 00:04:13.729 decide to add a new pair of shoes at the last 00:04:13.729 --> 00:04:16.529 minute, let's call that new blood from a hemorrhage 00:04:16.529 --> 00:04:19.670 or swelling from trauma. Something else inside 00:04:19.670 --> 00:04:22.170 that suitcase must be squeezed out, or the zipper 00:04:22.170 --> 00:04:24.829 breaks. That is a perfect visualization. And 00:04:24.829 --> 00:04:27.649 because the skull obviously has no zipper, the 00:04:27.649 --> 00:04:29.949 body desperately tries to compensate to make 00:04:29.949 --> 00:04:32.250 room for those new shoes. The first thing the 00:04:32.250 --> 00:04:34.910 brain does is place the CSF. It pushes it out. 00:04:35.009 --> 00:04:37.290 Yeah. It shunts it down into the spinal subarachnoid 00:04:37.290 --> 00:04:39.509 space. It basically says, we don't need all this 00:04:39.509 --> 00:04:41.149 fluid right now. Get it out of here. Which buys 00:04:41.149 --> 00:04:44.050 you some time, right? A little bit of time. But 00:04:44.050 --> 00:04:46.449 if the swelling continues, the brain moves to 00:04:46.449 --> 00:04:49.300 its next trick. It collapses its own cerebral 00:04:49.300 --> 00:04:51.540 veins to push venous blood out of the skull. 00:04:51.699 --> 00:04:53.860 But there has to be a limit to that. There is 00:04:53.860 --> 00:04:56.100 a hard mathematical limit to that compensation. 00:04:56.740 --> 00:04:59.319 You can only squeeze so much CSF and venous blood 00:04:59.319 --> 00:05:01.720 out before there's nothing left to squeeze. Okay, 00:05:01.720 --> 00:05:04.240 so let's trace this pathophysiology step by step. 00:05:04.740 --> 00:05:07.560 Let's say the trigger is a severe primary injury, 00:05:08.100 --> 00:05:10.839 like a traumatic car crash. The patient arrives 00:05:10.839 --> 00:05:14.459 in your ICU. That primary injury happens once. 00:05:14.759 --> 00:05:17.279 The initial impact is over. Correct. You can't 00:05:17.279 --> 00:05:19.660 uncrash the car. The primary injury is done. 00:05:20.220 --> 00:05:22.759 What you, the ICU nurse, are managing is the 00:05:22.759 --> 00:05:25.420 secondary injury, the aftermath. So the physiologic 00:05:25.420 --> 00:05:27.639 change here is tissue edema and blood accumulating. 00:05:27.839 --> 00:05:30.899 The compensation is displacing that CSF and venous 00:05:30.899 --> 00:05:33.639 blood. But once that limit is reached, the decompensation 00:05:33.639 --> 00:05:37.139 phase hits. The ICP rises sharply. As the pressure 00:05:37.139 --> 00:05:39.540 climbs past 20, the ventricles and the small 00:05:39.540 --> 00:05:42.100 blood vessels inside the brain literally compress 00:05:42.100 --> 00:05:43.899 under the weight of the swelling. Wait, if the 00:05:43.899 --> 00:05:45.819 blood vessels compress, then cerebral blood flow 00:05:45.819 --> 00:05:48.879 drops, right? Exactly. Cerebral blood flow, or 00:05:48.879 --> 00:05:52.339 CBF, plummets. The brain tissue is now being 00:05:52.339 --> 00:05:55.300 starved of oxygen, it becomes hypoxic, and if 00:05:55.300 --> 00:05:57.540 eventually the tissue begins to die, it becomes 00:05:57.540 --> 00:05:59.910 necrotic. But here's where I get confused, or 00:05:59.910 --> 00:06:02.290 at least where the physiology feels like this 00:06:02.290 --> 00:06:05.230 tragic irony. When the body is starved of oxygen, 00:06:05.550 --> 00:06:07.790 its natural defense mechanism is to open up the 00:06:07.790 --> 00:06:10.410 blood vessels, right? Vasodilation. It's trying 00:06:10.410 --> 00:06:13.029 to bring more oxygen to the starving tissue. 00:06:13.529 --> 00:06:16.850 Normally, yes. But in the brain, it is a lethal 00:06:16.850 --> 00:06:19.470 feedback loop. You've hit on the exact mechanism 00:06:19.470 --> 00:06:21.790 that kills these patients. Oh, wow. OK, walk 00:06:21.790 --> 00:06:24.170 me through it. So when brain tissue is starved 00:06:24.170 --> 00:06:27.350 of oxygen, normal aerobic metabolism fails. The 00:06:27.350 --> 00:06:29.649 cells switch to anaerobic metabolism, which produces 00:06:29.649 --> 00:06:32.430 a massive amount of lactic acid. At the same 00:06:32.430 --> 00:06:34.689 time, because blood flow is sluggish, carbon 00:06:34.689 --> 00:06:37.069 dioxide is accumulating in the brain. And CO2 00:06:37.069 --> 00:06:40.670 is a potent vasodilator. the most potent. Both 00:06:40.670 --> 00:06:43.189 acidosis and hypercacnea tell the smooth muscle 00:06:43.189 --> 00:06:45.610 of the cerebral arteries to relax. The brain 00:06:45.610 --> 00:06:47.970 is basically gasping for air, screaming at the 00:06:47.970 --> 00:06:50.110 blood vessels, open up, we need more oxygen right 00:06:50.110 --> 00:06:52.829 now. So the vessels dilate to bring in more arterial 00:06:52.829 --> 00:06:55.089 blood. But we just said the suitcase is already 00:06:55.089 --> 00:06:57.670 full. Opening the vessels means bringing more 00:06:57.670 --> 00:07:00.170 blood volume into a rigidly packed skull that 00:07:00.170 --> 00:07:03.149 has literally no room for it. Precisely. The 00:07:03.149 --> 00:07:05.620 vasodilation brings in more volume. which takes 00:07:05.620 --> 00:07:08.800 up more space, which spikes the ICP even further. 00:07:09.379 --> 00:07:11.660 That higher pressure then crushes the vessels 00:07:11.660 --> 00:07:14.100 even more, which causes more hypoxia, which causes 00:07:14.100 --> 00:07:16.839 more CO2 buildup, which causes more vasodilation. 00:07:17.100 --> 00:07:20.699 It is a vicious, inescapable cycle. It is. If 00:07:20.699 --> 00:07:23.139 you don't intervene, the pressure will seek the 00:07:23.139 --> 00:07:25.259 only exit available in the human skull, which 00:07:25.259 --> 00:07:27.939 is downward. downward through the form and magnum, 00:07:28.060 --> 00:07:29.959 the hole at the base of the skull where the spinal 00:07:29.959 --> 00:07:33.379 cord exits. Yes. The brain tissue literally pushes 00:07:33.379 --> 00:07:36.319 down and herniates through that opening, crushing 00:07:36.319 --> 00:07:38.879 the brain stem on its way out. Once the brain 00:07:38.879 --> 00:07:40.600 stem is crushed, the respiratory and cardiac 00:07:40.600 --> 00:07:43.920 centers fail and the patient dies. Okay, so as 00:07:43.920 --> 00:07:46.279 the bedside nurse, our entire goal is to catch 00:07:46.279 --> 00:07:48.180 this feedback loop before the brain starts looking 00:07:48.180 --> 00:07:50.540 for the exit. Let's break down the assessment. 00:07:50.680 --> 00:07:52.560 Because if we are looking for subtle signs, what 00:07:52.560 --> 00:07:54.980 does that actually look like in room four? The 00:07:54.980 --> 00:07:57.779 absolute earliest, most sensitive indicator of 00:07:57.779 --> 00:08:01.019 rising ICP is a change in the level of consciousness, 00:08:01.620 --> 00:08:04.379 or LOC. But we aren't just talking about a patient 00:08:04.379 --> 00:08:06.860 suddenly falling into a coma, right? No, no. 00:08:07.399 --> 00:08:10.259 A coma is a late sign. We are talking about incredibly 00:08:10.259 --> 00:08:13.300 subtle shifts. The patient who was chatting with 00:08:13.300 --> 00:08:16.620 you about their dog two hours ago now has a slight 00:08:16.620 --> 00:08:18.850 flattening of their affect. Like, they just don't 00:08:18.850 --> 00:08:21.129 care as much. Right. They seem a bit indifferent. 00:08:21.550 --> 00:08:23.610 Maybe they are slightly restless, picking at 00:08:23.610 --> 00:08:25.810 their blankets. Or you ask them to state their 00:08:25.810 --> 00:08:27.649 name, and there's a two or three second delay 00:08:27.649 --> 00:08:30.350 before they answer. It's a slowing of processing 00:08:30.350 --> 00:08:32.870 speed. That is so easy to write off as fatigue. 00:08:33.269 --> 00:08:35.470 Especially in an ICU where alarms are ringing 00:08:35.470 --> 00:08:37.110 all night. You might just think, ah, they're 00:08:37.110 --> 00:08:39.450 tired. Which is exactly why you have to be paranoid. 00:08:39.639 --> 00:08:43.159 Any unexplained drop in attention span or orientation 00:08:43.159 --> 00:08:46.779 is an ICP spike until proven otherwise. Wow. 00:08:46.940 --> 00:08:49.019 Okay. What about the classic signs? The ones 00:08:49.019 --> 00:08:51.159 that are a bit more obvious, but maybe not yet 00:08:51.159 --> 00:08:53.980 catastrophic. The classic signs include unexpected 00:08:53.980 --> 00:08:56.740 vomiting. And the key word there is unexpected. 00:08:57.220 --> 00:09:00.340 Meaning not preceded by nausea. Right. It's often 00:09:00.340 --> 00:09:03.240 sudden and can be projectile. It happens because 00:09:03.240 --> 00:09:05.639 the pressure is directly stimulating the medic 00:09:05.639 --> 00:09:08.649 center in the medulla. You also see morning headaches 00:09:08.649 --> 00:09:11.090 or nocturnal headaches that actually wake the 00:09:11.090 --> 00:09:13.509 patient up from sleep. Wait, why specifically 00:09:13.509 --> 00:09:15.669 at night or in the morning? Because when you 00:09:15.669 --> 00:09:18.549 lay flat... gravity is no longer helping the 00:09:18.549 --> 00:09:21.230 venous blood drain out of your head. Venous return 00:09:21.230 --> 00:09:23.970 slows down, which naturally increases the volume 00:09:23.970 --> 00:09:26.610 of blood in the skull slightly. Oh, I see. Yeah, 00:09:26.710 --> 00:09:28.889 for you or me. Our brain complies, no problem. 00:09:29.429 --> 00:09:31.830 But for a patient whose suitcase is already full, 00:09:32.350 --> 00:09:34.590 that slight volume increase from laying flat 00:09:34.590 --> 00:09:37.029 pushes them over the edge into pain. That makes 00:09:37.029 --> 00:09:40.370 total sense. Okay, let's move to the late dangerous 00:09:40.370 --> 00:09:42.970 signs, the ones that mean we are actively losing 00:09:42.970 --> 00:09:45.750 the battle and herniation is imminent. The most 00:09:45.750 --> 00:09:49.190 terrifying late sign is Cushing's triad. It is 00:09:49.190 --> 00:09:51.330 an absolute medical emergency signaling that 00:09:51.330 --> 00:09:53.990 the brainstem is actively being compressed. Let's 00:09:53.990 --> 00:09:55.990 unpack the triad. What are the three pieces? 00:09:56.330 --> 00:09:58.129 And more importantly, why are they happening? 00:09:58.529 --> 00:10:00.929 Let's connect the patho to the symptoms. First, 00:10:01.389 --> 00:10:04.389 you will see systolic hypertension with a widening 00:10:04.389 --> 00:10:07.600 pulse pressure. meaning the top number, the systolic 00:10:07.600 --> 00:10:10.919 shoots way up, say to 190 or 200, while the bottom 00:10:10.919 --> 00:10:14.240 number, the diastolic, stays the same or even 00:10:14.240 --> 00:10:17.039 drops. Why does the systolic shoot up? Because 00:10:17.039 --> 00:10:19.460 the brain is hypoxic, it sends a panic signal 00:10:19.460 --> 00:10:22.039 to the sympathetic nervous system to clamp down 00:10:22.039 --> 00:10:24.240 on peripheral blood vessels. Mm -hmm. It's trying 00:10:24.240 --> 00:10:26.980 to create a massive systemic blood pressure to 00:10:26.980 --> 00:10:29.919 physically force arterial blood up into the highly 00:10:29.919 --> 00:10:31.860 pressurized skull. It's trying to overcome the 00:10:31.860 --> 00:10:34.679 resistance. Exactly. Okay. So the body is jacking 00:10:34.679 --> 00:10:36.779 up the blood pressure to save the brain. What's 00:10:36.779 --> 00:10:39.600 the second part of the triad? Bradycardia. A 00:10:39.600 --> 00:10:42.440 slow, full, bounding heart rate. Wait. If the 00:10:42.440 --> 00:10:44.500 sympathetic nervous system is firing to raise 00:10:44.500 --> 00:10:47.100 blood pressure, shouldn't the heart rate be fast, 00:10:47.440 --> 00:10:50.159 tachycardia? You would think so, but the massive 00:10:50.159 --> 00:10:52.600 systemic blood pressure triggers the baroreceptors 00:10:52.600 --> 00:10:55.820 in the aortic arch. They sense this dangerously 00:10:55.820 --> 00:10:58.740 high pressure and send a signal via the vagus 00:10:58.740 --> 00:11:01.679 nerve to the heart to slow down, trying to protect 00:11:01.679 --> 00:11:04.019 the heart from blowing out. So you get this paradox 00:11:04.019 --> 00:11:06.200 sky -high blood pressure with a heart rate dropping 00:11:06.200 --> 00:11:09.379 into the 40s? It is chilling to see on a monitor. 00:11:09.529 --> 00:11:13.730 Wow. Okay. High systolic with wide pulse pressure, 00:11:14.070 --> 00:11:16.990 bradycardia, and the third piece. Irregular respirations. 00:11:17.970 --> 00:11:19.990 Often chain stokes respirations where they breathe 00:11:19.990 --> 00:11:22.830 fast and deep, then shallow, then stop breathing 00:11:22.830 --> 00:11:26.210 for a period of apnea. This happens because the 00:11:26.210 --> 00:11:28.649 physical pressure is finally crushing the respiratory 00:11:28.649 --> 00:11:31.889 control center in the medulla. So Cushing's triad, 00:11:32.269 --> 00:11:34.649 widening pulse pressure, bradycardia, irregular 00:11:34.649 --> 00:11:38.039 breathing, and Other late signs would be pupil 00:11:38.039 --> 00:11:41.299 changes, right? Like a unilateral fixed and dilated 00:11:41.299 --> 00:11:44.320 pupil. Yes, a blown pupil on one side. That happens 00:11:44.320 --> 00:11:46.779 when the temporal lobe starts to shift and physically 00:11:46.779 --> 00:11:49.539 pinches cranial nerve the third, the oculomotor 00:11:49.539 --> 00:11:51.940 nerve. If you see that, the brain is actively 00:11:51.940 --> 00:11:54.629 herniating. You'll also see posturing. Decorticate, 00:11:54.870 --> 00:11:57.289 which is abnormal flexion, pulling the arms tight 00:11:57.289 --> 00:11:59.149 into the core like they're protecting their chest. 00:11:59.250 --> 00:12:01.769 Right, drawing into the core. And then decerebrate, 00:12:02.009 --> 00:12:04.690 which is abnormal extension arms, stiffly extended 00:12:04.690 --> 00:12:07.350 outward and rotated. Which one is worse? Decerebrate 00:12:07.350 --> 00:12:09.110 is generally worse. It indicates damage much 00:12:09.110 --> 00:12:11.190 deeper in the midbrain or brainstem. All right, 00:12:11.190 --> 00:12:13.289 let's talk about how we actually monitor this 00:12:13.289 --> 00:12:15.789 pressure before we see Cushing's triad. We have 00:12:15.789 --> 00:12:18.909 CT and MRI for imaging, of course, but for moment 00:12:18.909 --> 00:12:22.539 to moment... ICU monitoring, the ventriculostomy 00:12:22.539 --> 00:12:26.740 is the gold standard, and there's also the LICOX 00:12:26.740 --> 00:12:29.159 catheter. I want to know what these numbers and 00:12:29.159 --> 00:12:31.379 waveforms actually mean. Let's start with the 00:12:31.379 --> 00:12:34.240 LICOX. It's a catheter inserted into the white 00:12:34.240 --> 00:12:37.059 matter of the brain. It measures brain tissue 00:12:37.059 --> 00:12:40.559 oxygenation, known as PBTO2, and brain temperature. 00:12:41.120 --> 00:12:43.960 Normal PBTO2 is 20 to 40 millimeters of mercury. 00:12:44.169 --> 00:12:46.970 So it's not like an SBO2 finger probe measuring 00:12:46.970 --> 00:12:49.190 oxygen saturation in the blood. It's measuring 00:12:49.190 --> 00:12:52.029 the actual oxygen tension in the tissue itself. 00:12:52.129 --> 00:12:54.909 Exactly. If you see a PBTO2 less than 20, that 00:12:54.909 --> 00:12:57.570 means regional ischemia. The oxygen is not extracting 00:12:57.570 --> 00:12:59.970 into the tissue. The cells are starving and that 00:12:59.970 --> 00:13:01.970 lethal vasodilation cycle is about to start. 00:13:02.110 --> 00:13:04.190 And the ventriculostomy. This is the catheter 00:13:04.190 --> 00:13:06.590 that goes directly into the lateral ventricle 00:13:06.590 --> 00:13:08.350 of the brain, right? It measures the ICP, but 00:13:08.350 --> 00:13:12.110 it also allows us to drain fluid. Yes. It gives 00:13:12.110 --> 00:13:15.419 you a continuous ICP number. But more importantly, 00:13:15.440 --> 00:13:18.100 it gives you a waveform. If you look at the monitor, 00:13:18.419 --> 00:13:21.600 a normal ICP wave has three distinct bumps per 00:13:21.600 --> 00:13:23.980 heartbeat, looking almost like a staircase going 00:13:23.980 --> 00:13:27.539 down. P1, P2, and P3. Okay, break those down 00:13:27.539 --> 00:13:30.419 for me. P1 is the percussion wave. It represents 00:13:30.419 --> 00:13:32.899 the arterial pulse of blood shooting into the 00:13:32.899 --> 00:13:36.019 brain. It should be the highest peak. P2 is the 00:13:36.019 --> 00:13:39.740 tidal wave. It represents brain compliance, how 00:13:39.740 --> 00:13:43.009 much stretch or give the brain tissue has. P3 00:13:43.009 --> 00:13:45.250 is the dichroic wave representing the closure 00:13:45.250 --> 00:13:47.669 of the aortic valve. So it should look like stairs 00:13:47.669 --> 00:13:50.289 going down. P1 is the highest, then P2 is lower, 00:13:50.370 --> 00:13:52.909 P3 is the lowest. Exactly. But if the brain is 00:13:52.909 --> 00:13:54.730 swelling and losing compliance, meaning the suitcase 00:13:54.730 --> 00:13:57.429 is completely full, that P2 wave will start to 00:13:57.429 --> 00:13:59.769 rise. When you look at the monitor and see P2 00:13:59.769 --> 00:14:02.690 riding higher than P1, it means ventricular compliance 00:14:02.690 --> 00:14:05.269 is poor. The brain has lost its ability to accommodate 00:14:05.269 --> 00:14:08.549 even a tiny drop more volume. That is such a 00:14:08.549 --> 00:14:11.470 crucial visual cue for a nurse. If P2 is higher 00:14:11.470 --> 00:14:14.250 than P1, you are on the edge of the cliff. So 00:14:14.250 --> 00:14:16.789 let's transition into nursing actions. You're 00:14:16.789 --> 00:14:19.710 the nurse. You notice that subtle LOC change. 00:14:20.169 --> 00:14:22.250 The attention span is dropping. What is your 00:14:22.250 --> 00:14:25.309 immediate ADPIE thought process? My diagnosis 00:14:25.309 --> 00:14:27.990 is inadequate tissue perfusion and decreased 00:14:27.990 --> 00:14:31.399 intracranial adaptive capacity. My plan, my measurable 00:14:31.399 --> 00:14:34.679 goal is to maintain the ICP less than 20 and 00:14:34.679 --> 00:14:37.059 maintain the cerebral perfusion pressure, the 00:14:37.059 --> 00:14:39.860 CPP, greater than 60. Let's pause right there. 00:14:39.960 --> 00:14:42.299 CPP, cerebral perfusion pressure. Break down 00:14:42.299 --> 00:14:44.100 the math for me because this trips up a lot of 00:14:44.100 --> 00:14:46.700 people. Sure. CPP is the net pressure required 00:14:46.700 --> 00:14:49.019 to physically push arterial blood into the brain 00:14:49.019 --> 00:14:51.460 against the resistance of the ICP. The formula 00:14:51.460 --> 00:14:54.570 is MAP minus ICP. You mean arterial pressure 00:14:54.570 --> 00:14:57.409 minus intracranial pressure? MAP minus ICP equals 00:14:57.409 --> 00:15:00.490 CPP. Yes. A normal CPP is 60 to 100 millimeters 00:15:00.490 --> 00:15:03.269 of mercury. If your CPP falls below 50, your 00:15:03.269 --> 00:15:05.789 brain is ischemic. Less than 30 is incompatible 00:15:05.789 --> 00:15:08.230 with life. The brain tissue is dead. Let's do 00:15:08.230 --> 00:15:10.450 a scenario. Let's say my patient's MAP is 90. 00:15:10.610 --> 00:15:14.809 Their ICP is 15. 90 minus 15 is 75. So my CPP 00:15:14.809 --> 00:15:17.370 is 75. We're in the safe zone of 60 to 100. Exactly. 00:15:17.470 --> 00:15:19.029 But let's say the patient gets a little agitated. 00:15:19.110 --> 00:15:22.769 They cough. Their ICP spikes to 25. And at the 00:15:22.769 --> 00:15:24.909 same time, In time, the propofol drip they're 00:15:24.909 --> 00:15:27.549 on drops their systemic blood pressure, so their 00:15:27.549 --> 00:15:30.549 MAP falls to 70. Now I have a MAP of 70 minus 00:15:30.549 --> 00:15:33.610 an ICP of 25, that equals 45. And at a CPP of 00:15:33.610 --> 00:15:36.889 45, the brain is actively dying. This is why 00:15:36.889 --> 00:15:39.289 we have to maintain a relatively strong systemic 00:15:39.289 --> 00:15:41.289 blood pressure in these patients. But there's 00:15:41.289 --> 00:15:43.809 a catch here, a concept called autoregulation. 00:15:44.000 --> 00:15:46.279 Which is the brain's ability to adjust its own 00:15:46.279 --> 00:15:48.399 vessel diameter to keep blood flow constant. 00:15:48.580 --> 00:15:51.580 Yes. But auto -regulation totally fails if the 00:15:51.580 --> 00:15:54.639 systemic MAP drops below 70 or goes above 150. 00:15:54.779 --> 00:15:57.700 If the MAP is 60, the brain can't dilate vessels 00:15:57.700 --> 00:16:00.799 enough to save itself. If the MAP is 160, the 00:16:00.799 --> 00:16:03.080 high pressure just blasts into the damaged brain, 00:16:03.440 --> 00:16:05.620 worsening edema. So you have a tightrope to walk 00:16:05.620 --> 00:16:07.679 with your vasopressors and fluids. OK, let's 00:16:07.679 --> 00:16:10.259 talk about priority nursing actions. If my patient's 00:16:10.259 --> 00:16:12.639 ICP is spiking, or I'm trying to prevent it from 00:16:12.639 --> 00:16:15.769 spiking, Rank my actions. What is my first, next 00:16:15.769 --> 00:16:18.990 T, and then? First, always maintain a patent 00:16:18.990 --> 00:16:21.870 airway. If their Glasgow Coma Scale drops below 00:16:21.870 --> 00:16:24.710 eight, you intubate. Period. Less than eight, 00:16:25.149 --> 00:16:28.230 intubate. If you walk in and hear snoring sounds 00:16:28.230 --> 00:16:31.250 in an altered patient, that is an airway obstruction 00:16:31.250 --> 00:16:33.350 from the tongue dropping back. It is not just 00:16:33.350 --> 00:16:35.029 deep sleep. Right. Fix the airway immediately 00:16:35.029 --> 00:16:37.570 because hypoxia, as we discussed, causes vasodilation 00:16:37.570 --> 00:16:40.799 and rapidly worsens ICP. Airway is secured. What 00:16:40.799 --> 00:16:44.139 is Next T? Next T optimize their physical position. 00:16:44.580 --> 00:16:47.120 Head of the bed elevated to 30 degrees, not flat 00:16:47.120 --> 00:16:49.799 and not 90 degrees. 30 is the sweet spot. Yeah. 00:16:49.960 --> 00:16:51.779 And you must keep the neck midline and neutral. 00:16:52.340 --> 00:16:54.779 Why is the neck position so critical? Because 00:16:54.779 --> 00:16:56.980 the venous blood drains out of the skull via 00:16:56.980 --> 00:16:59.539 the jugular veins in the neck. If the patient's 00:16:59.539 --> 00:17:01.519 head is twisted to the side or flexed down onto 00:17:01.519 --> 00:17:03.980 their chest, you are physically kinking the jugular 00:17:03.980 --> 00:17:05.980 veins. You are trapping all that venous blood 00:17:05.980 --> 00:17:08.480 inside the skull. Keep the head straight. Wow, 00:17:08.519 --> 00:17:10.400 that's such a simple mechanical fix that could 00:17:10.400 --> 00:17:13.799 save a life. Keep the drain pipes open. Okay, 00:17:13.799 --> 00:17:17.299 what is then? Then you limit interventions that 00:17:17.299 --> 00:17:19.940 spike pressure. Suctioning the endotracheal tube 00:17:19.940 --> 00:17:23.079 is necessary, but it massively spikes ICP because 00:17:23.079 --> 00:17:25.859 it induces a cough reflex. So you must limit 00:17:25.859 --> 00:17:27.799 suctioning to less than 10 seconds per pass, 00:17:28.160 --> 00:17:31.140 maximum of two passes, and you always pre -oxygenate 00:17:31.140 --> 00:17:34.200 with 100 % O2 beforehand to prevent that hypoxic 00:17:34.200 --> 00:17:36.200 vasodilation. And what about the environment? 00:17:36.559 --> 00:17:40.109 Total control. Dim lights, limit visitors. Cluster 00:17:40.109 --> 00:17:42.230 your care, but if clustering causes their ICP 00:17:42.230 --> 00:17:45.009 to stay elevated, space the care out. Prevent 00:17:45.009 --> 00:17:47.589 shivering at all costs because shivering massively 00:17:47.589 --> 00:17:49.990 increases the brain's metabolic demand for oxygen. 00:17:50.250 --> 00:17:52.269 Let's move to medications. This is where we break 00:17:52.269 --> 00:17:54.369 out the heavy hitters. We've got mannitol and 00:17:54.369 --> 00:17:57.309 we've got hypertonic saline. Both are osmotic 00:17:57.309 --> 00:17:59.549 therapies used to literally pull water out of 00:17:59.549 --> 00:18:01.450 the brain. But how do we choose between them? 00:18:01.609 --> 00:18:04.609 Let's start with mannitol. It is an osmotic diuretic 00:18:04.609 --> 00:18:08.069 given IV. It works in two phases. Instantly, 00:18:08.170 --> 00:18:10.549 it expands the blood plasma, which reduces blood 00:18:10.549 --> 00:18:12.849 viscosity in a head of grit. This makes the blood 00:18:12.849 --> 00:18:15.170 thinner so it flows better, which tells the brain 00:18:15.170 --> 00:18:18.049 it can constrict its vessels a bit. Then the 00:18:18.049 --> 00:18:20.430 osmotic phase kicks in. This is the sponge effect. 00:18:20.750 --> 00:18:23.349 Right. Manital creates a high osmotic gradient 00:18:23.349 --> 00:18:25.730 in the blood. It acts like a chemical sponge, 00:18:26.089 --> 00:18:28.170 drawing free water directly out of the swollen 00:18:28.170 --> 00:18:30.710 brain tissue, across the blood -brain barrier, 00:18:30.990 --> 00:18:33.150 and into the vascular space, where the kidneys 00:18:33.150 --> 00:18:35.950 then pee it out. So what's the catch? Why not 00:18:35.950 --> 00:18:38.190 use it for everyone? because it's a diuretic. 00:18:38.549 --> 00:18:41.089 It pulls fluid out of the whole body. You must 00:18:41.089 --> 00:18:43.789 check serum osmolality before giving it. If their 00:18:43.789 --> 00:18:45.930 blood is already too concentrated osmolality 00:18:45.930 --> 00:18:49.109 over 320, you hold it. You also hold it in severe 00:18:49.109 --> 00:18:50.990 renal disease because the kidneys can't clear 00:18:50.990 --> 00:18:53.380 it. So what if we can't use mannitol or we need 00:18:53.380 --> 00:18:56.119 something else? We use hypertonic saline, usually 00:18:56.119 --> 00:18:58.779 3 % saline, sometimes higher. It works via the 00:18:58.779 --> 00:19:01.539 same osmotic principle. It severely concentrates 00:19:01.539 --> 00:19:04.400 the sodium in the bloodstream, creating a massive 00:19:04.400 --> 00:19:07.339 osmotic pool of water out of the edematous brain 00:19:07.339 --> 00:19:09.599 cells. But unlike mannitol, it doesn't make you 00:19:09.599 --> 00:19:11.799 pee it out, right? It just keeps the fluid in 00:19:11.799 --> 00:19:14.440 the vascular space. Exactly. Which means the 00:19:14.440 --> 00:19:17.019 blood volume expands drastically. You have to 00:19:17.019 --> 00:19:18.920 monitor their blood pressure and listen to their 00:19:18.920 --> 00:19:21.420 lungs obsessively because pulling all that fluid 00:19:21.420 --> 00:19:24.519 into the vascular space can easily cause severe 00:19:24.519 --> 00:19:27.299 fluid overload and pulmonary edema. You also 00:19:27.299 --> 00:19:29.700 must check serum sodium constantly. We usually 00:19:29.700 --> 00:19:32.779 target a slightly high sodium level, around 145 00:19:32.779 --> 00:19:35.859 to 155, but you don't want it going to dangerously 00:19:35.859 --> 00:19:38.559 high levels. What about sedation? Keeping the 00:19:38.559 --> 00:19:41.279 patient calm is critical to keeping the metabolic 00:19:41.279 --> 00:19:44.980 demand low. We prefer propofol or dexmedetomidine, 00:19:45.119 --> 00:19:48.420 which is Presodex. Why those specifically over, 00:19:48.420 --> 00:19:51.859 say, a continuous drip of a benzo like lorazepam? 00:19:52.059 --> 00:19:54.630 Because of the half -life. Propofol and Presodax 00:19:54.630 --> 00:19:56.690 have very short half -lives. If I have a neuro 00:19:56.690 --> 00:19:58.289 patient, I need to know what their actual brain 00:19:58.289 --> 00:20:00.990 is doing. I can turn off the propofol drip, and 00:20:00.990 --> 00:20:02.769 within five to ten minutes, the drug clears enough 00:20:02.769 --> 00:20:05.150 for the patient to wake up. I can perform a totally 00:20:05.150 --> 00:20:06.869 accurate neuro check, see if they squeeze my 00:20:06.869 --> 00:20:08.769 fingers, check their pupils, and then turn the 00:20:08.769 --> 00:20:10.769 sedation right back on. You cannot do that with 00:20:10.769 --> 00:20:13.210 long -acting benzodiazepines. They just stay 00:20:13.210 --> 00:20:17.619 snowed for hours. And if the ICP is totally refractory 00:20:17.619 --> 00:20:20.599 to sedation, to mannitol, to everything, what 00:20:20.599 --> 00:20:23.559 is the final medical step? High dose barbiturates 00:20:23.559 --> 00:20:26.779 like pentobarbital. We use this to induce a barbiturate 00:20:26.779 --> 00:20:29.700 coma. It drastically cuts the brain's metabolic 00:20:29.700 --> 00:20:32.460 demand. We titrate the drip until the continuous 00:20:32.460 --> 00:20:36.220 EG shows burst suppression, meaning the brainwaves 00:20:36.220 --> 00:20:38.599 are almost completely flat, just tiny bursts 00:20:38.599 --> 00:20:40.859 of activity. We are putting the brain to sleep 00:20:40.859 --> 00:20:43.779 to save it from itself. That is intense. Let's 00:20:43.779 --> 00:20:45.940 touch on the ventriculostomy procedure itself. 00:20:46.319 --> 00:20:48.519 As the bedside nurse, what is my biggest trap 00:20:48.519 --> 00:20:50.740 here? What is the thing I cannot mess up? Leveling 00:20:50.740 --> 00:20:54.059 the transducer. The ventriculostomy drain relies 00:20:54.059 --> 00:20:57.039 on gravity. The transducer must be leveled precisely 00:20:57.039 --> 00:20:59.460 to the tragus of the patient's ear. The tragus? 00:20:59.519 --> 00:21:01.259 That little cartilage flap at the front of the 00:21:01.259 --> 00:21:04.119 ear canal? Why there? Because anatomically, the 00:21:04.119 --> 00:21:06.119 tragus aligns perfectly with the form in a Monroe 00:21:06.119 --> 00:21:08.680 inside the brain. which is the exact point of 00:21:08.680 --> 00:21:11.099 the ventricles. You have to re -level this transducer 00:21:11.099 --> 00:21:13.640 with a laser level every single time the patient 00:21:13.640 --> 00:21:16.059 is repositioned, even an inch. What happens if 00:21:16.059 --> 00:21:17.920 I forget, say the patient slides down in bed 00:21:17.920 --> 00:21:20.039 so now their head is lower than the transducer? 00:21:20.259 --> 00:21:22.839 If the transducer is too high relative to their 00:21:22.839 --> 00:21:26.400 head, the monitor will falsely read a low ICP. 00:21:26.799 --> 00:21:28.420 You will look at the monitor, think they are 00:21:28.420 --> 00:21:31.119 fine, and completely miss a life -threatening 00:21:31.119 --> 00:21:33.990 pressure spike. Oh wow, and what if I lower the 00:21:33.990 --> 00:21:36.569 bed and the transducer is now too low below their 00:21:36.569 --> 00:21:39.009 ear? If the transducer is too low, the monitor 00:21:39.009 --> 00:21:42.109 will read a falsely high ICP and the system might 00:21:42.109 --> 00:21:44.789 overdrain cerebrospinal fluid out of the skull. 00:21:44.970 --> 00:21:48.509 If you drain CSF too fast, the ventricles can 00:21:48.509 --> 00:21:50.970 literally collapse on themselves or you can cause 00:21:50.970 --> 00:21:53.630 a subdural hematoma as the brain shrinks away 00:21:53.630 --> 00:21:55.869 from the skull. So exact leveling to the tragus 00:21:55.869 --> 00:21:59.349 every single time. And obviously strict aseptic 00:21:59.349 --> 00:22:01.369 technique because a straight line into the brain 00:22:01.369 --> 00:22:04.029 is a highway for infection. Non -negotiable sterility, 00:22:04.349 --> 00:22:06.630 absolutely. Okay, let's talk fluids and electrolytes 00:22:06.630 --> 00:22:09.269 broadly. We have to keep these patients uvelemic. 00:22:09.369 --> 00:22:11.470 We don't want them dry. We don't want them overloaded. 00:22:11.789 --> 00:22:14.490 We are monitoring closely for two classic pituitary 00:22:14.490 --> 00:22:18.150 complications, diabetes insipidus, or DI, and 00:22:18.150 --> 00:22:20.430 syndrome of inappropriate antidiuretic hormone, 00:22:20.549 --> 00:22:24.190 or SIADH. Yes. The pituitary gland is sitting 00:22:24.190 --> 00:22:26.410 right at the base of the brain, easily compressed 00:22:26.410 --> 00:22:29.349 by swelling. If it stops secreting ADH, you get 00:22:29.349 --> 00:22:31.690 diabetes insipidus. The patient will suddenly 00:22:31.690 --> 00:22:34.150 dump massive amounts of dilute urine liters an 00:22:34.150 --> 00:22:37.069 hour. Their serum sodium will skyrocket because 00:22:37.069 --> 00:22:39.970 they're losing all their free water. And SIADH 00:22:39.970 --> 00:22:42.910 is the exact opposite. Right. The damaged pituitary 00:22:42.910 --> 00:22:45.829 dumps too much ADH. The patient stops peeing 00:22:45.829 --> 00:22:48.509 entirely. They retain all their free water, which 00:22:48.509 --> 00:22:51.650 dilutes their blood, causing a dilutional hyponatremia. 00:22:51.849 --> 00:22:55.130 Low sodium in a neuro patient is incredibly dangerous 00:22:55.130 --> 00:22:57.829 because it pulls water into the cells, worsening 00:22:57.829 --> 00:22:59.970 brain edema. Speaking of fluids pulling water 00:22:59.970 --> 00:23:02.849 into cells, what IV fluids are we hanging for 00:23:02.849 --> 00:23:05.529 our routine piggybacks or maintenance? We use 00:23:05.529 --> 00:23:08.789 .9 % normal saline for everything. Never, under 00:23:08.789 --> 00:23:13.470 any circumstances, hang D5W or .45 % normal saline 00:23:13.470 --> 00:23:15.390 for a neuro patient. Because they are hypotonic? 00:23:15.529 --> 00:23:19.200 Yes. DeFiW is isotonic in the bag, but the moment 00:23:19.200 --> 00:23:21.599 it enters the bloodstream, the body metabolizes 00:23:21.599 --> 00:23:24.220 the dextrose, leaving behind only free water. 00:23:24.759 --> 00:23:27.180 Free water is incredibly hypotonic. It lowers 00:23:27.180 --> 00:23:29.660 the serum osmolality of the blood. Because of 00:23:29.660 --> 00:23:32.519 osmosis, that water will flee the vascular space 00:23:32.519 --> 00:23:35.599 and drive directly into the cells. In a brain 00:23:35.599 --> 00:23:38.359 that is already swelling, hanging DeFiW will 00:23:38.359 --> 00:23:41.460 cause a massive spike in cerebral edema. It is 00:23:41.460 --> 00:23:44.819 a fatal error. Good to know. Normal saline only. 00:23:45.399 --> 00:23:47.599 Let's summarize deterioration. We've talked about 00:23:47.599 --> 00:23:50.079 the mechanisms, but if I'm looking at my patient, 00:23:50.440 --> 00:23:52.599 how do I know they are getting worse before herniation 00:23:52.599 --> 00:23:54.759 actually happens? The patient is getting worse 00:23:54.759 --> 00:23:56.440 if you look at their ventriculostomy monitor 00:23:56.440 --> 00:23:58.720 and that P2 wave starts riding higher than P1. 00:23:58.940 --> 00:24:01.319 That means they have lost compliance. They're 00:24:01.319 --> 00:24:03.420 getting worse if you're checking vitals and you 00:24:03.420 --> 00:24:05.339 see their systolic blood pressure slowly trending 00:24:05.339 --> 00:24:07.619 up over an hour while their heart rate is slowly 00:24:07.619 --> 00:24:09.980 trending down. That is Cushing's triad knocking 00:24:09.980 --> 00:24:12.119 at the door. And they're getting worse if you 00:24:12.119 --> 00:24:14.420 do a pain stimulus check. And their previous 00:24:14.420 --> 00:24:17.299 decorticate flexion turns into decerebrate extension. 00:24:17.400 --> 00:24:19.299 The damage is moving deeper into the brain stem. 00:24:19.579 --> 00:24:22.339 What's the escalation protocol here? What's a 00:24:22.339 --> 00:24:25.400 notify the doctor versus call a code? If you 00:24:25.400 --> 00:24:28.759 see a gradual ICP drift upward, say it goes from 00:24:28.759 --> 00:24:31.779 14 to 18 over an hour, you notify the provider. 00:24:32.319 --> 00:24:34.890 But first, assess your own interventions. Are 00:24:34.890 --> 00:24:37.289 they in pain? Do they have full bladder? Are 00:24:37.289 --> 00:24:39.430 their endotracheal ties too tight around their 00:24:39.430 --> 00:24:42.109 neck, blocking venous return? Fix the nursing 00:24:42.109 --> 00:24:45.849 issues first, then call. And the immediate emergency. 00:24:46.049 --> 00:24:47.630 If you shine a light in their eyes and you see 00:24:47.630 --> 00:24:50.740 a sudden unilateral fixed and dilated pupil. 00:24:51.000 --> 00:24:53.160 That is not a call and wait for a callback. That 00:24:53.160 --> 00:24:55.180 is a code or immediate intervention. That is 00:24:55.180 --> 00:24:56.779 uncle herniation happening right in front of 00:24:56.779 --> 00:24:58.960 you. You immediately notify the provider and 00:24:58.960 --> 00:25:00.940 the neurosurgeon, ensure the airway is clear, 00:25:01.400 --> 00:25:03.579 hyperventilate the patient briefly to drop CO2 00:25:03.579 --> 00:25:06.099 and constrict vessels, and prepare for emergency 00:25:06.099 --> 00:25:08.319 surgical decompression. Let's hit a quick ICU 00:25:08.319 --> 00:25:10.519 pearl or an exam trap. I see this all the time 00:25:10.519 --> 00:25:12.740 with novice nurses. You walk in, the patient 00:25:12.740 --> 00:25:15.079 is unconscious, but they squeeze your hand when 00:25:15.079 --> 00:25:17.980 you put yours in their palm. Do not. be fooled 00:25:17.980 --> 00:25:21.599 by the hand squeeze. In an unconscious patient, 00:25:21.859 --> 00:25:23.880 hand squeezing is very often a primitive palmar 00:25:23.880 --> 00:25:26.640 grasp reflex. It means nothing about their actual 00:25:26.640 --> 00:25:29.299 cortical function. Nautis nurses will chart follows 00:25:29.299 --> 00:25:31.680 commands, purposeful movement, because the patient 00:25:31.680 --> 00:25:34.359 squeezed their hand. So how do we actually test 00:25:34.359 --> 00:25:36.640 purposeful motor response? You apply a noxious 00:25:36.640 --> 00:25:39.660 stimulus. a trapezius pinch, or supraorbital 00:25:39.660 --> 00:25:42.279 pressure, you watch what they do. If they reach 00:25:42.279 --> 00:25:44.279 up, cross the midline and try to bat your hand 00:25:44.279 --> 00:25:46.640 away, they are localizing pain that is purposeful. 00:25:46.680 --> 00:25:49.180 If they just rigidly flex their arms inward, 00:25:49.599 --> 00:25:52.539 that is abnormal decorticate posturing. Big difference. 00:25:52.619 --> 00:25:55.880 Another trapezius tubes. Yes. If a patient has 00:25:55.880 --> 00:25:58.339 severe facial trauma or a suspected basilar skull 00:25:58.339 --> 00:26:01.160 fracture, you never insert a nasogastric tube. 00:26:01.420 --> 00:26:03.839 The cribriform plate, the bone separating the 00:26:03.839 --> 00:26:06.059 nasal cavity from the brain, could be shattered. 00:26:06.440 --> 00:26:08.660 If you push an NG tube up the nose, it can go 00:26:08.660 --> 00:26:10.440 straight through the fracture and coil up inside 00:26:10.440 --> 00:26:12.660 the frontal lobe of the brain. You must use an 00:26:12.660 --> 00:26:15.400 oral gastric tube instead. That is literal nightmare 00:26:15.400 --> 00:26:17.890 fuel. Okay, let's tie this whole first section 00:26:17.890 --> 00:26:20.390 together with some intensivist thinking. This 00:26:20.390 --> 00:26:22.549 is how we want our listeners to process information. 00:26:23.269 --> 00:26:26.009 Okay, problem. Your neuro patient develops a 00:26:26.009 --> 00:26:30.069 fever of 101 .5, failing physiology. The increased 00:26:30.069 --> 00:26:32.089 temperature spikes the metabolic demand of the 00:26:32.089 --> 00:26:34.450 brain tissue. Exactly. Immediate threat. Because 00:26:34.450 --> 00:26:36.869 the brain is hotter, it demands more oxygen. 00:26:37.289 --> 00:26:40.230 To get that oxygen, it triggers cerebral vasodilation. 00:26:40.789 --> 00:26:43.589 Those dilated vessels steal space in the skull 00:26:43.589 --> 00:26:46.859 leading to an imminent ICP spike. intervention, 00:26:47.680 --> 00:26:50.500 aggressive cooling measures, ice packs, cooling 00:26:50.500 --> 00:26:52.920 blankets, and antipyretics like acetaminophen. 00:26:53.319 --> 00:26:55.279 But crucially, you must monitor them to ensure 00:26:55.279 --> 00:26:58.059 they do not start shivering. Spot on. And reassessment. 00:26:58.279 --> 00:27:00.660 Recheck the core temp and watch the ICP waveform 00:27:00.660 --> 00:27:02.859 return to normal compliance. That is beautiful. 00:27:02.940 --> 00:27:05.259 That is exactly how an elite ICU nurse thinks. 00:27:05.539 --> 00:27:07.099 You don't just treat the fever to make the number 00:27:07.099 --> 00:27:09.099 go down. You treat the fever because you know 00:27:09.099 --> 00:27:11.220 the heat is physically dilating blood vessels 00:27:11.220 --> 00:27:14.680 inside a closed box. So if we had to distill 00:27:14.680 --> 00:27:17.500 this entire foundation into our Pareto 8020, 00:27:17.920 --> 00:27:20.640 if you remember only five things from intracranial 00:27:20.640 --> 00:27:24.740 regulation, number one, core patho. Hypoxia and 00:27:24.740 --> 00:27:27.359 hypercapnia cause cerebral vasodilation, which 00:27:27.359 --> 00:27:29.680 steals limited skull space and specs pressure. 00:27:29.900 --> 00:27:32.630 Number two. Key assessment. A subtle change in 00:27:32.630 --> 00:27:34.750 level of consciousness is the earliest sign. 00:27:35.230 --> 00:27:37.769 Cushing's triad -high systolic low heart rate 00:27:37.769 --> 00:27:40.569 irregular breathing is a late fatal sign. Number 00:27:40.569 --> 00:27:43.809 three. Most dangerous complication. Brain stem 00:27:43.809 --> 00:27:46.769 herniation. Number four. Priority nursing action. 00:27:47.549 --> 00:27:49.630 Maintain the airway and elevate the head of the 00:27:49.630 --> 00:27:52.390 bed to 30 degrees with the neck perfectly neutral. 00:27:52.730 --> 00:27:55.650 Number five. Most important treatment. osmotic 00:27:55.650 --> 00:27:58.549 therapy like mannitol or hypertonic saline combined 00:27:58.549 --> 00:28:01.069 with CSF drainage. Your one sentence clinical 00:28:01.069 --> 00:28:03.609 picture for this section. An unconscious patient 00:28:03.609 --> 00:28:06.230 with a ventriculostomy whose rising blood pressure 00:28:06.230 --> 00:28:08.789 and dropping heart rate signal impending brainstem 00:28:08.789 --> 00:28:11.269 compression. The action trigger. If you see a 00:28:11.269 --> 00:28:13.809 sudden unilateral fixed and dilated pupil, think 00:28:13.809 --> 00:28:16.289 uncle herniation and do immediately notify the 00:28:16.289 --> 00:28:18.589 neurosurgeon while preparing for emergency decompression. 00:28:18.849 --> 00:28:21.349 Okay, so now that we deeply understand the mechanics 00:28:21.349 --> 00:28:24.250 of normal pressure and swelling, What happens 00:28:24.250 --> 00:28:26.430 when an external force suddenly shatters that 00:28:26.430 --> 00:28:29.589 equilibrium? Let's talk trauma. This is section 00:28:29.589 --> 00:28:33.569 two, traumatic brain injury and hematomas. TBI 00:28:33.569 --> 00:28:35.809 is essentially physical damage to the scalp, 00:28:36.190 --> 00:28:39.569 skull, or brain. It can be diffuse, meaning spread 00:28:39.569 --> 00:28:41.910 out across the entire brain like a severe concussion, 00:28:42.569 --> 00:28:45.430 or it can be focal, localized to one specific 00:28:45.430 --> 00:28:49.079 spot, like a contusion or a bleed. Why does the 00:28:49.079 --> 00:28:51.319 ICU nurse's role matter so much here? I mean, 00:28:51.400 --> 00:28:53.859 if the trauma already happened, what are we actually 00:28:53.859 --> 00:28:56.579 doing? Because of the timeline of death. Most 00:28:56.579 --> 00:28:58.960 TBI deaths occur immediately at the scene from 00:28:58.960 --> 00:29:00.880 the primary impact. We can't do anything about 00:29:00.880 --> 00:29:03.700 that. But the second wave of death happens hours 00:29:03.700 --> 00:29:06.259 or days later. The ICU nurse is the one who prevents 00:29:06.259 --> 00:29:08.660 those delayed deaths. The deaths from the secondary 00:29:08.660 --> 00:29:11.539 injury, the expanding bleeds, the ischemia, the 00:29:11.539 --> 00:29:13.880 edema. Who is getting these TBIs? We usually 00:29:13.880 --> 00:29:16.990 think of young guys on motorcycles. Yes. Falls 00:29:16.990 --> 00:29:19.089 in motor vehicle accidents are the top causes. 00:29:19.789 --> 00:29:22.309 Men are twice as likely as women to suffer TBI. 00:29:23.349 --> 00:29:26.089 But there is a massive, incredibly vulnerable 00:29:26.089 --> 00:29:29.190 risk group that we see constantly. Older adults 00:29:29.190 --> 00:29:31.849 on anticoagulant medications. Like a Liquis or 00:29:31.849 --> 00:29:34.769 Warfarin. Right. For an 80 -year -old on a blood 00:29:34.769 --> 00:29:37.410 thinner, a minor fall from a standing height 00:29:37.410 --> 00:29:39.890 that just causes a little bump on the head can 00:29:39.890 --> 00:29:43.170 turn into a lethal, slow -pooling bleed. We have 00:29:43.170 --> 00:29:44.990 to be hyper -vigilant with that demographic. 00:29:45.240 --> 00:29:47.960 Let's dig into the pathophysiology of specific 00:29:47.960 --> 00:29:51.299 injuries. Let's start with diffuse axonal injury, 00:29:51.619 --> 00:29:55.299 or DAI. When I first learned about this, I pictured 00:29:55.299 --> 00:29:57.880 the brain violently shaking and the axons, the 00:29:57.880 --> 00:30:00.519 long cables connecting the neurons, just physically 00:30:00.519 --> 00:30:02.980 snapping in half on impact. That's what we used 00:30:02.980 --> 00:30:04.960 to think. But research shows it's actually much 00:30:04.960 --> 00:30:07.140 more insidious. The initial trauma, the rapid 00:30:07.140 --> 00:30:09.680 acceleration and deceleration of the brain, doesn't 00:30:09.680 --> 00:30:12.430 usually tear the axons right away. Instead, the 00:30:12.430 --> 00:30:14.809 shearing forces stretch the axons and change 00:30:14.809 --> 00:30:17.170 their cellular function. They damage the cytoskeleton. 00:30:17.170 --> 00:30:19.609 So what happens next? Over the next 12 to 24 00:30:19.609 --> 00:30:22.970 hours, the damaged axons lose their ability to 00:30:22.970 --> 00:30:26.109 transport proteins. They start to swell. They 00:30:26.109 --> 00:30:28.130 balloon up until they finally disconnect and 00:30:28.130 --> 00:30:30.730 undergo wallerian degeneration. It's an evolving 00:30:30.730 --> 00:30:33.390 injury. This is why a patient might look okay 00:30:33.390 --> 00:30:36.910 on a CT scan at hour one, but by hour 24, they're 00:30:36.910 --> 00:30:40.750 in a deep coma. The axons literally swell themselves 00:30:40.750 --> 00:30:43.410 to death. Now what about coup contra coup injuries? 00:30:43.509 --> 00:30:45.910 This is a classic term. This happens in high 00:30:45.910 --> 00:30:48.750 -velocity impacts. Say you are in a car and you 00:30:48.750 --> 00:30:51.250 hit a brick wall. Your skull stops instantly. 00:30:51.789 --> 00:30:53.930 But your brain, which is floating in fluid, keeps 00:30:53.930 --> 00:30:56.609 moving forward. The brain strikes the front of 00:30:56.609 --> 00:30:58.569 the inside of the skull. That's the coup injury, 00:30:58.769 --> 00:31:00.690 the primary impact. Usually the frontal lobe 00:31:00.690 --> 00:31:03.650 getting bruised. Right. But then the brain rebounds. 00:31:03.769 --> 00:31:05.369 It bounces backward off the front of the skull 00:31:05.369 --> 00:31:07.660 and slams into the back of the skull. That's 00:31:07.660 --> 00:31:09.839 the contra -coup injury. So you end up with massive 00:31:09.839 --> 00:31:12.539 contusions on opposite sides of the brain. And, 00:31:12.539 --> 00:31:14.119 fascinatingly, because of the physics of the 00:31:14.119 --> 00:31:16.619 fluid dynamics, the secondary impact, the contra 00:31:16.619 --> 00:31:18.259 -coup of the back of the head, is often actually 00:31:18.259 --> 00:31:21.200 worse than the initial front impact. Wow. Okay. 00:31:21.779 --> 00:31:24.440 Let's move to the assessment of trauma. Let's 00:31:24.440 --> 00:31:26.720 talk about skull fractures, specifically the 00:31:26.720 --> 00:31:29.220 basilar skull fracture. This is a break in the 00:31:29.220 --> 00:31:31.720 bones at the base of the skull. What are the 00:31:31.720 --> 00:31:34.710 classic signs we are hunting for? You are looking 00:31:34.710 --> 00:31:37.650 for cerebrospinal fluid leaking out of the body, 00:31:38.230 --> 00:31:40.349 rhinorrhea, which is CSF leaking from the nose, 00:31:41.029 --> 00:31:42.970 and otorhea, which is leaking from the ears. 00:31:43.170 --> 00:31:45.170 The Dura has been born, so the fluid just drips 00:31:45.170 --> 00:31:48.130 out. But how do I know if it's CSF and not just 00:31:48.130 --> 00:31:50.710 a runny nose from crying or krama? You use the 00:31:50.710 --> 00:31:53.710 halo sign. If clear or slightly bloody fluid 00:31:53.710 --> 00:31:56.269 is leaking from the ear or nose, you let it drip 00:31:56.269 --> 00:31:58.710 onto a clean white gauze pad. You wait a few 00:31:58.710 --> 00:32:01.880 minutes. If it's CSF mixed with blood, the heavier 00:32:01.880 --> 00:32:03.819 red blood cells will coalesce in the center of 00:32:03.819 --> 00:32:06.480 the drop. The lighter CSF will fan out around 00:32:06.480 --> 00:32:09.099 it, creating a distinct yellowish ring, a halo 00:32:09.099 --> 00:32:12.240 encircling the blood. That is such a cool, practical 00:32:12.240 --> 00:32:14.839 bedside test. It is. You also look for battle 00:32:14.839 --> 00:32:17.200 sign, which is post -curricular ecchymosis, severe 00:32:17.200 --> 00:32:19.619 bruising right behind the ears over the mastoid 00:32:19.619 --> 00:32:22.920 bone, and raccoon eyes, which is bilateral periorbital 00:32:22.920 --> 00:32:25.519 bruising. Both indicate blood pooling at the 00:32:25.519 --> 00:32:27.460 base of the skull from a fracture. Now let's 00:32:27.460 --> 00:32:30.440 talk about the big scary ones, the hematomas. 00:32:31.140 --> 00:32:33.579 Epidural versus subdural. I want to spend some 00:32:33.579 --> 00:32:35.559 time here because the difference in how these 00:32:35.559 --> 00:32:40.180 act is wild. What is an epidural hematoma? An 00:32:40.180 --> 00:32:42.519 epidural hematoma is bleeding into the space 00:32:42.519 --> 00:32:45.579 between the tough outer layer of the brain, the 00:32:45.579 --> 00:32:47.759 dormator, and the inner surface of the skull. 00:32:48.119 --> 00:32:50.809 It is almost always an arterial bleed. typically 00:32:50.809 --> 00:32:53.450 a tear in the middle meningeal artery, often 00:32:53.450 --> 00:32:55.470 caused by a linear fracture of the temporal bone. 00:32:55.609 --> 00:32:57.769 And because it's arterial, it's under high pressure. 00:32:57.910 --> 00:33:00.329 Imagine a high pressure water main bursting inside 00:33:00.329 --> 00:33:02.750 a wall versus a slow leak from a garden hose. 00:33:03.269 --> 00:33:05.970 The epidural is the bursting water main. Exactly. 00:33:06.130 --> 00:33:08.690 It fills the epidural space incredibly fast. 00:33:09.170 --> 00:33:12.069 This creates a highly specific, classic clinical 00:33:12.069 --> 00:33:14.549 presentation that you must recognize. The patient 00:33:14.549 --> 00:33:16.509 suffers the trauma and is knocked unconscious 00:33:16.509 --> 00:33:19.069 at the scene. That's the initial impact. Right. 00:33:19.279 --> 00:33:21.740 Then they wake up. This is the lucid interval. 00:33:22.140 --> 00:33:23.960 They might be totally awake, talking to you, 00:33:23.980 --> 00:33:26.180 asking what happened to their car. But while 00:33:26.180 --> 00:33:28.140 they are talking to you, that torn meningeal 00:33:28.140 --> 00:33:30.740 artery is pumping high pressure blood into the 00:33:30.740 --> 00:33:33.099 skull, stripping the dura away from the bone 00:33:33.099 --> 00:33:35.599 and creating a massive pool of blood. The suitcase 00:33:35.599 --> 00:33:38.980 is filling up. Rapidly. Once the compliance is 00:33:38.980 --> 00:33:41.720 maxed out, the patient experiences a catastrophic 00:33:41.720 --> 00:33:44.970 rapid decrease in LOC. They go from talking to 00:33:44.970 --> 00:33:47.690 you, to confuse, to slurring their words, to 00:33:47.690 --> 00:33:50.569 comatose, to blown pupil, to posturing within 00:33:50.569 --> 00:33:52.650 minutes as the arterial blood crushes the brain 00:33:52.650 --> 00:33:55.990 inward. It's an absolute drop everything neurologic 00:33:55.990 --> 00:33:59.000 emergency. They need a burr hole or craniotomy 00:33:59.000 --> 00:34:01.660 immediately to evacuate the blood. OK, that's 00:34:01.660 --> 00:34:03.819 the epidural. What about the subdural hematoma, 00:34:04.019 --> 00:34:06.299 the slow garden hose? A subdural hematoma is 00:34:06.299 --> 00:34:08.320 bleeding between the dura mater and the arachnoid 00:34:08.320 --> 00:34:10.940 layer underneath it. This bleed is usually venous. 00:34:11.179 --> 00:34:12.920 It comes from the tearing of the small bridging 00:34:12.920 --> 00:34:14.980 veins that drain the surface of the brain into 00:34:14.980 --> 00:34:17.119 the sagittal sinus. And because veins are low 00:34:17.119 --> 00:34:19.239 pressure systems, it develops much more slowly. 00:34:19.679 --> 00:34:22.579 Right. An acute subdural presents within 24 to 00:34:22.579 --> 00:34:25.349 48 hours of the injury. A subacute might take 00:34:25.349 --> 00:34:28.809 two to 14 days to show signs, and a chronic subdural 00:34:28.809 --> 00:34:31.289 hematoma can take weeks or even months to present. 00:34:31.449 --> 00:34:33.630 This is where that differential pattern recognition 00:34:33.630 --> 00:34:36.190 is so fascinating. Let's talk about the elderly 00:34:36.190 --> 00:34:38.909 and the chronic subdural. Imagine you have an 00:34:38.909 --> 00:34:41.409 80 -year -old patient presenting to the ER with 00:34:41.409 --> 00:34:44.329 new onset confusion, memory loss, and lethargy. 00:34:44.829 --> 00:34:47.429 The family says they are acting bizarrely. The 00:34:47.429 --> 00:34:50.250 immediate instinct is to think stroke or the 00:34:50.250 --> 00:34:53.900 rapid onset of dementia or a UTI. But you must 00:34:53.900 --> 00:34:56.320 ask the family. Did they fall in the last month? 00:34:56.719 --> 00:34:58.780 Why does it take a whole month? Two reasons. 00:34:59.019 --> 00:35:01.800 First, the venous bleed is very slow. Second, 00:35:02.059 --> 00:35:03.900 older adults naturally have some brain atrophy. 00:35:04.300 --> 00:35:06.119 Their brain actually shrinks as they age, which 00:35:06.119 --> 00:35:08.099 means there is more empty space inside the skull. 00:35:08.420 --> 00:35:10.380 When the bridging vein tears from a minor bump 00:35:10.380 --> 00:35:12.940 on the head, the blood just slowly pools into 00:35:12.940 --> 00:35:15.500 that extra space. It can pool for weeks without 00:35:15.500 --> 00:35:17.940 causing any pressure symptoms. But eventually, 00:35:18.059 --> 00:35:19.760 the pool gets big enough that it finally presses 00:35:19.760 --> 00:35:22.059 on the brain tissue. It's honestly terrifying 00:35:22.059 --> 00:35:24.579 to think that a slow venous bleed can totally 00:35:24.579 --> 00:35:27.440 mimic Alzheimer's disease. You could have a patient 00:35:27.440 --> 00:35:30.099 placed in memory care when in reality they just 00:35:30.099 --> 00:35:33.219 need a burr hole to drain the old dark blood 00:35:33.219 --> 00:35:36.420 off their brain. It happens, which is why any 00:35:36.420 --> 00:35:38.920 elderly patient with new onset confusion gets 00:35:38.920 --> 00:35:41.840 a CT scan, especially if they are on a liquid 00:35:41.840 --> 00:35:45.659 or warfarin. Diagnostics for TBI. The non -contrast 00:35:45.659 --> 00:35:48.420 CT scan is the absolute gold standard for rapid 00:35:48.420 --> 00:35:51.480 trauma diagnosis. It shows fresh blood instantly 00:35:51.480 --> 00:35:53.900 as bright white. And we must always assume a 00:35:53.900 --> 00:35:57.019 cervical spine injury with head trauma. The forces 00:35:57.019 --> 00:35:59.579 required to damage the brain almost always put 00:35:59.579 --> 00:36:02.719 the neck at risk. C -spine CTs or x -rays are 00:36:02.719 --> 00:36:05.420 mandatory, and the patient stays in a rigid cervical 00:36:05.420 --> 00:36:08.320 collar until cleared by a doctor. From an ADPIE 00:36:08.320 --> 00:36:10.500 perspective, your assessment priority is hunting 00:36:10.500 --> 00:36:13.159 for those subtle fluid leaks, checking the pillowcase 00:36:13.159 --> 00:36:16.320 for a halo sign. Your nursing diagnosis is risk 00:36:16.320 --> 00:36:18.980 for ineffective cerebral tissue perfusion. Your 00:36:18.980 --> 00:36:21.199 planning is entirely focused on preventing secondary 00:36:21.199 --> 00:36:23.900 ischemia. Keep the oxygen up, keep the blood 00:36:23.900 --> 00:36:26.139 pressure stable. For implementation, you mentioned 00:36:26.139 --> 00:36:28.460 earlier that we can test nasal drainage for glucose 00:36:28.460 --> 00:36:31.190 to see if it's CSF. Yes, using your dextrose 00:36:31.190 --> 00:36:34.449 sticks. Normal mucus does not have glucose. Cerebrospinal 00:36:34.449 --> 00:36:36.389 fluid does. If it tests positive for glucose, 00:36:36.789 --> 00:36:39.030 it's CSF. But there's a huge exam trap here, 00:36:39.110 --> 00:36:41.050 right? Yes. If there is blood mixed in the fluid, 00:36:41.170 --> 00:36:43.369 the glucose test is completely invalid. Blood 00:36:43.369 --> 00:36:45.730 contains its own glucose. If you test a bloody 00:36:45.730 --> 00:36:48.110 nose, it will test positive for glucose, and 00:36:48.110 --> 00:36:50.030 you might falsely assume they have a skull fracture. 00:36:50.590 --> 00:36:52.250 If blood is present, throw the dextrose sticks 00:36:52.250 --> 00:36:54.449 away and rely entirely on the halo sign on the 00:36:54.449 --> 00:36:57.860 gauze pad. So good. What are my priority nursing 00:36:57.860 --> 00:37:01.820 actions in the trauma bay or the ICU when a severe 00:37:01.820 --> 00:37:05.440 TBI rolls in? First, stabilize the cervical spine 00:37:05.440 --> 00:37:07.940 while simultaneously managing the airway using 00:37:07.940 --> 00:37:10.239 the jaw thrust maneuver, not the head tilt chin 00:37:10.239 --> 00:37:13.719 lift, to protect the neck. Next, apply high flow 00:37:13.719 --> 00:37:16.679 oxygen via a non -rebreather mask and establish 00:37:16.679 --> 00:37:20.269 two large bore IVs for fluid resuscitation. Then 00:37:20.269 --> 00:37:22.849 control any massive external bleeding with sterile 00:37:22.849 --> 00:37:24.829 pressure dressings. For medications, we talked 00:37:24.829 --> 00:37:27.150 about sedation earlier. In trauma, do we want 00:37:27.150 --> 00:37:29.929 them sedated? It's a delicate balance. If their 00:37:29.929 --> 00:37:33.389 ICP is fine, we actually want to avoid heavy 00:37:33.389 --> 00:37:36.010 sedatives initially, if possible, because they 00:37:36.010 --> 00:37:38.989 mask our serial narrow assessments. We need to 00:37:38.989 --> 00:37:41.269 know if they're waking up or deteriorating. But 00:37:41.269 --> 00:37:44.110 we do routinely use prophylactic anti -seizure 00:37:44.110 --> 00:37:47.030 medications, like Leviteratetam or phenatoin. 00:37:47.369 --> 00:37:50.590 for the first 7 to 10 days after a severe TBI. 00:37:50.710 --> 00:37:53.869 Because a seizure would skyrocket their metabolic 00:37:53.869 --> 00:37:56.750 demand and their ICP. Exactly. Post -traumatic 00:37:56.750 --> 00:37:59.230 seizures are common and devastating. Procedures. 00:37:59.610 --> 00:38:01.730 We've mentioned burr holes for rapid decompression 00:38:01.730 --> 00:38:03.730 of an epidural bleed. What is the difference 00:38:03.730 --> 00:38:06.670 between a craniotomy and a craniectomy? In a 00:38:06.670 --> 00:38:09.090 craniotomy, the neurosurgeon cuts a flap of bone 00:38:09.090 --> 00:38:12.000 out of the skull, goes in, stops the bleeding, 00:38:12.320 --> 00:38:14.159 evacuates the hematoma, and then puts the bone 00:38:14.159 --> 00:38:16.219 flap back in place, securing it with plates. 00:38:16.760 --> 00:38:19.340 The skull is closed. In a craniotomy, they remove 00:38:19.340 --> 00:38:20.960 the bone flap and they leave it off. Wait, they 00:38:20.960 --> 00:38:23.820 just leave a hole in the skull? Yes. They usually 00:38:23.820 --> 00:38:26.079 tuck the bone flap into the patient's abdomen, 00:38:26.340 --> 00:38:28.920 just under the fat layer, to keep the bone tissue 00:38:28.920 --> 00:38:31.719 alive and sterile. They leave the skull open 00:38:31.719 --> 00:38:33.320 because they know the brain is going to swell 00:38:33.320 --> 00:38:35.960 massively over the next few days. By removing 00:38:35.960 --> 00:38:39.039 the bone, they give the swollen brain room to 00:38:39.039 --> 00:38:41.599 expand outward. instead of herniating downward 00:38:41.599 --> 00:38:44.119 into the brain stem. Months later, when the swelling 00:38:44.119 --> 00:38:46.300 is gone, they do a cranioplasty to put the bone 00:38:46.300 --> 00:38:48.940 back. Hemodynamics and fluids for trauma. We 00:38:48.940 --> 00:38:51.079 mentioned maintaining normothermia. Fever is 00:38:51.079 --> 00:38:54.000 bad. Very bad. Shivering is worse. And we give 00:38:54.000 --> 00:38:56.320 fluids very cautiously. We need a strong blood 00:38:56.320 --> 00:38:59.559 pressure to maintain CPP. But overzealous fluid 00:38:59.559 --> 00:39:01.940 resuscitation can exacerbate cerebral edema. 00:39:02.239 --> 00:39:04.159 You might need vasopressors instead of just dumping 00:39:04.159 --> 00:39:06.960 liters of saline into them. Let's do some intensivist 00:39:06.960 --> 00:39:09.980 thinking for trauma. Problem. The patient has 00:39:09.980 --> 00:39:13.619 a confirmed basilar skull fracture. Failing physiology 00:39:13.619 --> 00:39:16.059 and threat. The dura mater is torn at the base 00:39:16.059 --> 00:39:18.820 of the skull. This opens a direct unsealed pathway 00:39:18.820 --> 00:39:21.599 for bacteria from the sinuses, the nose, or the 00:39:21.599 --> 00:39:23.579 ears directly into the sterile brain cavity. 00:39:24.079 --> 00:39:26.099 The immediate threat is fulminant meningitis. 00:39:26.300 --> 00:39:28.800 Action. Advocate for prophylactic antibiotics. 00:39:29.300 --> 00:39:31.579 And crucially, as the nurse, you strictly avoid 00:39:31.579 --> 00:39:35.139 any nasal insertions. No nasal intubation, no 00:39:35.139 --> 00:39:38.219 nasogastric tubes, and no nasal suctioning. Perfect. 00:39:38.699 --> 00:39:40.960 You are recognizing that the structural damage 00:39:40.960 --> 00:39:43.559 creates an infection highway, and you are altering 00:39:43.559 --> 00:39:45.860 your nursing care to prevent driving a tube up 00:39:45.860 --> 00:39:48.019 that highway. And what about packing a leaking 00:39:48.019 --> 00:39:51.880 nose or ear? Never pack it. If CSF is leaking 00:39:51.880 --> 00:39:54.769 out, let it leak. Place a loose, sterile pad 00:39:54.769 --> 00:39:56.829 under the nose or ear to catch the fluid and 00:39:56.829 --> 00:39:59.289 change it when soiled. If you plug the leak with 00:39:59.289 --> 00:40:01.789 packing, you increase the intracranial pressure, 00:40:01.989 --> 00:40:04.269 and worse, you force the dirty infected fluid 00:40:04.269 --> 00:40:06.710 to backwash into the brain. Let's summarize TBI 00:40:06.710 --> 00:40:08.769 with our five things to remember. Number one, 00:40:09.030 --> 00:40:12.010 core patho. Arterial bleeds like epidural hematomas 00:40:12.010 --> 00:40:14.469 kill fast due to high pressure. Venous bleeds 00:40:14.469 --> 00:40:17.630 like subdural hematomas kill slowly. Number two, 00:40:18.070 --> 00:40:20.710 key assessment. The halo sign confirms CSF leakage 00:40:20.710 --> 00:40:23.099 from a skull fracture. Do not use the glucose 00:40:23.099 --> 00:40:25.539 test if blood is present. Number three, most 00:40:25.539 --> 00:40:28.139 dangerous complication. An unrecognized epidural 00:40:28.139 --> 00:40:30.719 hematoma entering the rapid deterioration phase. 00:40:31.139 --> 00:40:34.099 Number four, priority nursing action. Assume 00:40:34.099 --> 00:40:37.219 a neck injury and stabilize the C -spine simultaneously 00:40:37.219 --> 00:40:40.340 with securing the airway. Number five, most important 00:40:40.340 --> 00:40:42.960 treatment. Immediate surgical evacuation for 00:40:42.960 --> 00:40:46.500 large symptomatic hematomas. And your one sentence 00:40:46.500 --> 00:40:50.070 clinical picture for TBI. a trauma patient who 00:40:50.070 --> 00:40:53.349 briefly woke up but is now rapidly losing consciousness 00:40:53.349 --> 00:40:56.110 as a torn meningeal artery fills their skull 00:40:56.110 --> 00:40:59.130 with blood. Action trigger. If you see clear 00:40:59.130 --> 00:41:01.090 fluid dripping from the nose after head trauma, 00:41:01.710 --> 00:41:04.110 think basilar skull fracture and do tests for 00:41:04.110 --> 00:41:07.030 glucose while strictly avoiding any nasal tubes. 00:41:07.349 --> 00:41:09.489 Which brings us perfectly into section three, 00:41:09.889 --> 00:41:12.349 brain tumors and cranial surgery. We just talked 00:41:12.349 --> 00:41:14.090 about trauma, which is the sudden occupation 00:41:14.090 --> 00:41:16.530 of space. The suitcase is filled in seconds. 00:41:16.840 --> 00:41:19.260 But tumors are completely different. The space 00:41:19.260 --> 00:41:21.679 occupation is incredibly gradual. This is all 00:41:21.679 --> 00:41:23.400 about the compliance curve of the brain, right? 00:41:23.500 --> 00:41:25.300 The curve is relatively flat for a long time. 00:41:25.360 --> 00:41:28.059 Same, the brain adapts. Right. As the tumor slowly 00:41:28.059 --> 00:41:30.360 grows over months, the brain gradually pushes 00:41:30.360 --> 00:41:33.119 out more and more CSF and venous blood to make 00:41:33.119 --> 00:41:35.539 room. The patient might be totally asymptomatic. 00:41:35.940 --> 00:41:37.519 But eventually you reach the end of the flat 00:41:37.519 --> 00:41:39.400 part of the curve and hit the steep vertical 00:41:39.400 --> 00:41:42.469 wall. The compensation is maxed out. At that 00:41:42.469 --> 00:41:44.730 point, even a tiny millimeter of tumor growth 00:41:44.730 --> 00:41:48.469 causes a massive exponential spike in ICP. So 00:41:48.469 --> 00:41:51.829 the 80 -20 overview here. We are dealing with 00:41:51.829 --> 00:41:54.530 primary or metastatic cell growth in the brain. 00:41:55.150 --> 00:41:57.489 It matters because, unlike tumors in the rest 00:41:57.489 --> 00:42:00.650 of the body, even histologically benign tumors 00:42:00.650 --> 00:42:03.349 are deadly if they grow in an inaccessible area 00:42:03.349 --> 00:42:07.070 and raise ICP. Exactly. A benign meningioma that 00:42:07.070 --> 00:42:09.250 can't be removed will kill you just as surely 00:42:09.250 --> 00:42:12.170 as a malignant glioblastoma simply by crushing 00:42:12.170 --> 00:42:15.949 the brainstem. The must -know facts. Menostatic 00:42:15.949 --> 00:42:18.210 tumors are the most common brain tumors overall, 00:42:18.710 --> 00:42:20.329 usually spreading from the lung or the breast. 00:42:20.849 --> 00:42:22.510 If we're talking about primary tumors that start 00:42:22.510 --> 00:42:24.389 in the brain, meningiomas are the most common. 00:42:24.690 --> 00:42:26.949 Let's look at the pathophysiology of how these 00:42:26.949 --> 00:42:28.969 tumors actually cause damage, aside from just 00:42:28.969 --> 00:42:30.929 taking up physical space. The real enemy here 00:42:30.929 --> 00:42:34.219 is vasogenic edema. As the tumor grows, it infiltrates 00:42:34.219 --> 00:42:36.280 local tissue and demand its own blood supply. 00:42:36.800 --> 00:42:38.460 But the blood vessels that the tumor builds are 00:42:38.460 --> 00:42:40.639 poorly constructed. They lack the tight junctions 00:42:40.639 --> 00:42:43.019 of a normal blood -brain barrier. The blood -brain 00:42:43.019 --> 00:42:45.239 barrier is usually highly selective, right? It 00:42:45.239 --> 00:42:46.900 keeps the large stuff out of the brain tissue. 00:42:47.079 --> 00:42:50.699 Yes. But the tumor's vessels are leaky. This 00:42:50.699 --> 00:42:53.840 disruption allows large molecules, like proteins, 00:42:54.260 --> 00:42:56.920 to leak directly from the blood into the interstitial 00:42:56.920 --> 00:42:59.940 brain tissue. And basic osmosis dictates that 00:42:59.940 --> 00:43:02.599 water follows protein. So the leaky proteins 00:43:02.599 --> 00:43:04.880 pull free water out of the blood and into the 00:43:04.880 --> 00:43:07.800 brain, causing massive localized swelling in 00:43:07.800 --> 00:43:09.900 the extracellular space surrounding the tumor. 00:43:10.460 --> 00:43:12.280 If the tumor is located near the ventricles, 00:43:12.679 --> 00:43:15.320 its physical mass can also clamp down and obstruct 00:43:15.320 --> 00:43:18.659 the normal flow of CSF, causing hydrocephalus, 00:43:18.840 --> 00:43:20.920 which just adds more pressure to the system. 00:43:21.460 --> 00:43:23.659 Assessment. We mentioned this earlier, but the 00:43:23.659 --> 00:43:26.280 classic sign of a brain tumor is a dull, constant 00:43:26.280 --> 00:43:28.679 headache that is worse at night or that awakens 00:43:28.679 --> 00:43:30.760 the patient from a dead sleep. And again, that's 00:43:30.760 --> 00:43:32.820 because laying flat removes the gravity assist 00:43:32.820 --> 00:43:35.500 for venous drainage, spiking the ICP just enough 00:43:35.500 --> 00:43:38.000 to cause pain. You also need to look for new 00:43:38.000 --> 00:43:41.460 onset seizures in an adult. If a 45 year old 00:43:41.460 --> 00:43:44.380 with no history of epilepsy suddenly has a grand 00:43:44.380 --> 00:43:47.360 mal seizure, a brain tumor is at the absolute 00:43:47.360 --> 00:43:50.000 top of the differential list. The tumor acts 00:43:50.000 --> 00:43:52.440 as an irritant to the electrical pathways. And 00:43:52.440 --> 00:43:54.719 what if the tumor is in the frontal lobe? The 00:43:54.719 --> 00:43:57.340 frontal lobe controls executive function, personality, 00:43:57.639 --> 00:44:00.480 and emotional regulation. A patient with a frontal 00:44:00.480 --> 00:44:03.559 lobe tumor might present with bizarre personality 00:44:03.559 --> 00:44:05.940 changes. This is a great differential pattern 00:44:05.940 --> 00:44:08.599 recognition moment. Imagine you have a previously 00:44:08.599 --> 00:44:11.760 stable professional adult. Suddenly, they start 00:44:11.760 --> 00:44:14.000 losing emotional control, they become highly 00:44:14.000 --> 00:44:16.519 impulsive, making wildly inappropriate comments, 00:44:16.659 --> 00:44:18.699 or having sudden outbursts of rage. Right, the 00:44:18.699 --> 00:44:20.960 family thinks they're having a mid -life crisis 00:44:20.960 --> 00:44:23.260 or a psychiatric breakdown or just acting out 00:44:23.260 --> 00:44:26.179 of bad behavior. But if you see that sudden loss 00:44:26.179 --> 00:44:28.079 of inhibition, you have to think frontal lobe 00:44:28.079 --> 00:44:30.639 lesion. The physical hardware running their personality 00:44:30.639 --> 00:44:33.690 is being crushed. It is vital to support the 00:44:33.690 --> 00:44:35.230 family through that because watching a loved 00:44:35.230 --> 00:44:37.829 one's personality disintegrate is devastating. 00:44:38.230 --> 00:44:40.030 And they need to understand it is a physical 00:44:40.030 --> 00:44:42.650 disease, not a choice the patient is making. 00:44:43.090 --> 00:44:45.730 Diagnostics for tumors rely heavily on the MRI. 00:44:46.150 --> 00:44:48.829 It is highly sensitive for small lesions, much 00:44:48.829 --> 00:44:51.690 better than a CT scan for tissue detail. And 00:44:51.690 --> 00:44:54.190 then a tissue biopsy, often using stereotactic 00:44:54.190 --> 00:44:57.030 guidance, determines the exact histology, whether 00:44:57.030 --> 00:44:59.530 it's an astrocytoma, glioblastoma, et cetera. 00:44:59.679 --> 00:45:02.559 For your ADPIE, your assessment before surgery 00:45:02.559 --> 00:45:05.460 must establish a rock -solid baseline. You need 00:45:05.460 --> 00:45:07.780 to know exactly what their LOC is, their motor 00:45:07.780 --> 00:45:09.539 strength out of five, their sensory function. 00:45:09.719 --> 00:45:11.460 You need to know that before they go to the OR, 00:45:11.579 --> 00:45:14.159 so when they come back to the ICU, you know if 00:45:14.159 --> 00:45:16.559 a deficit is new from the surgery or if they 00:45:16.559 --> 00:45:18.820 already had it. The nursing diagnosis is risk 00:45:18.820 --> 00:45:21.199 for injury related to seizures or altered behavior. 00:45:21.579 --> 00:45:23.739 Planning is to maximize neurologic functioning 00:45:23.739 --> 00:45:26.789 and control pain. Implantation means protecting 00:45:26.789 --> 00:45:29.130 them from self -harm padded side rails if they 00:45:29.130 --> 00:45:31.610 are seizing, close supervision if their judgment 00:45:31.610 --> 00:45:33.690 is impaired. And let's talk about priority nursing 00:45:33.690 --> 00:45:35.929 actions after they come back from cranial surgery. 00:45:36.090 --> 00:45:39.789 What is my first, next T, and then? First, prevent 00:45:39.789 --> 00:45:42.809 increased ICP. And the most immediate way you 00:45:42.809 --> 00:45:45.710 do that post -op is with precise head of bed 00:45:45.710 --> 00:45:49.090 positioning. But it depends on the surgery. If 00:45:49.090 --> 00:45:51.909 they had a super tentorial surgery, meaning above 00:45:51.909 --> 00:45:54.570 the tentorium in the cerebral hemispheres, you 00:45:54.570 --> 00:45:57.289 elevate the head of the bed 30 to 45 degrees 00:45:57.289 --> 00:46:00.130 to promote venous drainage. And if they had an 00:46:00.130 --> 00:46:03.510 infratentorial surgery down in the cerebellum 00:46:03.510 --> 00:46:05.750 or brainstem? You keep them flat or slightly 00:46:05.750 --> 00:46:08.289 elevated at 10 to 15 degrees and you do not flex 00:46:08.289 --> 00:46:11.530 their neck. Okay, what is NEXT -T? NEXT -T, monitor 00:46:11.530 --> 00:46:13.809 that surgical dressing obsessively. You're looking 00:46:13.809 --> 00:46:16.650 for excess bleeding, obviously, but you are specifically 00:46:16.650 --> 00:46:19.550 hunting for clear drainage. If you see excessive 00:46:19.550 --> 00:46:22.230 clear fluid soaking the dressing, that is a CSF 00:46:22.230 --> 00:46:25.110 leak, and then administer antimetics at the first 00:46:25.110 --> 00:46:27.289 sign of nausea, the physical act of retching 00:46:27.289 --> 00:46:30.050 and vomiting causes massive spikes in intra -thoracic 00:46:30.050 --> 00:46:32.409 pressure, which translates directly to massive 00:46:32.409 --> 00:46:34.750 spikes in intracranial pressure. You must prevent 00:46:34.750 --> 00:46:36.489 them from throwing up. But there is a caveat 00:46:36.489 --> 00:46:40.429 with the antimetics, right? Yes. Avoid promethazine, 00:46:40.769 --> 00:46:44.449 or fenugin, if possible. It causes severe somnolence 00:46:44.449 --> 00:46:47.280 and sedation. If you knock the patient out with 00:46:47.280 --> 00:46:50.099 Fenergen, you ruin your ability to do an accurate 00:46:50.099 --> 00:46:53.840 hourly neuro assessment. Use Ondansetron Zofran. 00:46:53.980 --> 00:46:57.360 instead. Medications for tumors. We use a corticosteroid 00:46:57.360 --> 00:47:00.619 here, dexamethasone. Yes, dexamethasone is crucial. 00:47:01.019 --> 00:47:03.179 It directly treats that vasogenic edema we talked 00:47:03.179 --> 00:47:05.780 about earlier. It stabilizes the cell membranes 00:47:05.780 --> 00:47:08.179 and tightens up the leaky blood -brain barrier 00:47:08.179 --> 00:47:10.920 around the tumor, drastically reducing the swelling. 00:47:11.159 --> 00:47:13.500 But wait, earlier in the TBI section you explicitly 00:47:13.500 --> 00:47:15.699 said we do not use steroids for head trauma. 00:47:15.900 --> 00:47:18.699 Correct. That is a massive NCLE -X and critical 00:47:18.699 --> 00:47:21.639 care exam trap. Steroids are not recommended 00:47:21.639 --> 00:47:23.480 for traumatic brain injury. They have been shown 00:47:23.480 --> 00:47:26.420 to increase mortality and trauma. But for tumors 00:47:26.420 --> 00:47:29.460 and infections, dexamethasone is a primary treatment. 00:47:29.659 --> 00:47:32.320 What about chemotherapy? The most common is temozolomide, 00:47:32.400 --> 00:47:34.500 or temodar. It's an oral chemo drug. The brilliant 00:47:34.500 --> 00:47:36.639 thing about it is that it spontaneously converts 00:47:36.639 --> 00:47:38.880 in the body into a form that can cross the blood 00:47:38.880 --> 00:47:41.440 -brain barrier, which most chemo drugs cannot 00:47:41.440 --> 00:47:44.280 do. But the nursing monitoring for it? It causes 00:47:44.280 --> 00:47:46.809 severe myelosuppression. You have to monitor 00:47:46.809 --> 00:47:49.289 their absolute neutrophil count and their platelets 00:47:49.289 --> 00:47:51.909 closely because they are at high risk for infection 00:47:51.909 --> 00:47:54.250 and bleeding. Let's talk post -op complications, 00:47:54.630 --> 00:47:58.090 specifically ventricular shunts. If a tumor causes 00:47:58.090 --> 00:48:00.969 hydrocephalus, the surgeon might place a shunt 00:48:00.969 --> 00:48:04.349 to route the excess CSF from the ventricles down 00:48:04.349 --> 00:48:06.789 into the peritoneal cavity in the abdomen where 00:48:06.789 --> 00:48:09.889 the body reabsorbs it. The most dangerous complication 00:48:09.889 --> 00:48:12.570 here is a shunt malfunction. The tubing gets 00:48:12.570 --> 00:48:14.929 blocked by protein or blood. So the patient is 00:48:14.929 --> 00:48:17.170 getting worse if they have a ventricular shunt 00:48:17.170 --> 00:48:21.010 and they suddenly develop a decreasing LOC restlessness 00:48:21.010 --> 00:48:23.650 and start vomiting. That is classic shunt failure. 00:48:24.190 --> 00:48:26.469 The fluid is backing up into the brain. causing 00:48:26.469 --> 00:48:29.050 acute hydrocephalus, it requires immediate surgical 00:48:29.050 --> 00:48:31.230 revision. And for escalation, what if they have 00:48:31.230 --> 00:48:33.329 those symptoms, but they also have a fever and 00:48:33.329 --> 00:48:35.889 a stiff neck? You notify the provider immediately 00:48:35.889 --> 00:48:38.289 because that is a shunt infection. The hardware 00:48:38.289 --> 00:48:40.650 is infected, tracking bacteria directly into 00:48:40.650 --> 00:48:44.030 the ventricles. Here's a huge ICU pearl for positioning. 00:48:44.170 --> 00:48:46.050 We talked about craniectomies earlier, where 00:48:46.050 --> 00:48:49.409 the bone flap is removed and left off. Yes. If 00:48:49.409 --> 00:48:52.429 a patient has had a craniectomy, you never Under 00:48:52.429 --> 00:48:54.670 any circumstances, position the patient on the 00:48:54.670 --> 00:48:57.150 operative side. Because there is no bone protecting 00:48:57.150 --> 00:48:59.090 the brain. Right. If you lay them on that side, 00:48:59.329 --> 00:49:01.210 the physical weight of their head is resting 00:49:01.210 --> 00:49:04.230 entirely on unprotected, swollen brain tissue. 00:49:04.610 --> 00:49:07.710 You will cause immense ischemia and damage. Always 00:49:07.710 --> 00:49:09.530 place a sign at the head of the bed, alerting 00:49:09.530 --> 00:49:11.650 the entire care team to the craniacomy site. 00:49:12.090 --> 00:49:15.409 Intensivist thinking for tumors. Problem. Post 00:49:15.409 --> 00:49:17.409 -op cerebral edema around the resection site. 00:49:17.809 --> 00:49:21.289 Threat. Increased ICP and herniation. Intervention. 00:49:21.630 --> 00:49:24.309 Administer ordered corticosteroids like dexamethasone, 00:49:24.469 --> 00:49:26.369 maintain precise head positioning based on the 00:49:26.369 --> 00:49:29.010 surgical site, and prevent vomiting. Re -assessment. 00:49:29.530 --> 00:49:31.869 Monitor the LOC hourly and check the dressing 00:49:31.869 --> 00:49:34.309 for clear CSF leaks. Beautifully summarized, 00:49:34.329 --> 00:49:36.389 if you remember only five things for brain tumors. 00:49:36.929 --> 00:49:39.769 Number one, core petho. Tumors cause vasogenic 00:49:39.769 --> 00:49:42.170 edema by building leaky blood vessels that disrupt 00:49:42.170 --> 00:49:44.730 the blood -brain barrier. Number two, key assessment. 00:49:45.010 --> 00:49:46.530 Headaches that are worse at night or like the 00:49:46.530 --> 00:49:49.309 patient up from sleep. Number three, most dangerous 00:49:49.309 --> 00:49:52.199 complication. post -op cerebral edema, or an 00:49:52.199 --> 00:49:54.760 acute hemorrhage into the tumor bed. Number four, 00:49:55.099 --> 00:49:57.940 priority nursing action. Precise head positioning 00:49:57.940 --> 00:50:00.800 post -op and absolutely never on the craniectomy 00:50:00.800 --> 00:50:03.679 side. Number five, most important treatment. 00:50:04.119 --> 00:50:06.599 Surgical resection combined with targeted radiation 00:50:06.599 --> 00:50:09.360 or chemotherapy. And the one -sentence clinical 00:50:09.360 --> 00:50:12.400 picture. An adult with new onset seizures and 00:50:12.400 --> 00:50:15.360 personality changes who requires meticulous ICP 00:50:15.360 --> 00:50:18.340 management and steroid therapy following a craniotomy. 00:50:18.539 --> 00:50:21.800 Action trigger. If you see excessive clear drainage 00:50:21.800 --> 00:50:25.219 on a post -craniotomy dressing, think CSF leak 00:50:25.219 --> 00:50:28.219 and do notify the surgeon immediately while keeping 00:50:28.219 --> 00:50:30.340 the patient perfectly still to prevent further 00:50:30.340 --> 00:50:33.079 tearing. Excellent. Let's move to the final piece 00:50:33.079 --> 00:50:35.000 of the puzzle. We've covered bleeding filling 00:50:35.000 --> 00:50:37.179 the space. We've covered mass growths filling 00:50:37.179 --> 00:50:39.599 the space. But what happens when the fluid itself 00:50:39.599 --> 00:50:42.940 becomes the enemy? Section 4, inflammatory conditions, 00:50:43.340 --> 00:50:46.039 meningitis and encephalitis. In these conditions, 00:50:46.360 --> 00:50:48.099 severe inflammation is the primary driver of 00:50:48.099 --> 00:50:50.960 the ICP spike. Meningitis is the inflammation 00:50:50.960 --> 00:50:52.739 of the meninges, the protective layers around 00:50:52.739 --> 00:50:55.400 the brain, and the CSF itself. Encephalitis is 00:50:55.400 --> 00:50:57.239 the inflammation of the actual brain parenchyma, 00:50:57.320 --> 00:50:59.900 the tissue itself. This matters incredibly because 00:50:59.900 --> 00:51:02.820 untreated bacterial meningitis is nearly 100 00:51:02.820 --> 00:51:06.539 % fatal. And unlike a tumor or a car crash, it 00:51:06.539 --> 00:51:09.159 is a massive contagion risk for the nursing staff 00:51:09.159 --> 00:51:13.090 and the other patients on the unit. Streptococcus 00:51:13.090 --> 00:51:15.550 pneumonia and Neisseria meningititis are the 00:51:15.550 --> 00:51:18.550 top bacterial culprits. Viral meningitis is more 00:51:18.550 --> 00:51:21.690 common, but usually less severe. Viral encephalitis 00:51:21.690 --> 00:51:24.929 is often caused by herpes simplex virus, HSV, 00:51:25.210 --> 00:51:27.829 or mosquito -borne viruses like West Nile. Let's 00:51:27.829 --> 00:51:30.429 trace the pathophysiology of bacterial meningitis. 00:51:30.750 --> 00:51:33.210 How does a simple sinus infection turn into a 00:51:33.210 --> 00:51:36.070 lethal brain swelling? The organism enters the 00:51:36.070 --> 00:51:38.210 central nervous system, usually crossing over 00:51:38.210 --> 00:51:39.989 from the respiratory tract or the bloodstream. 00:51:40.119 --> 00:51:43.000 Once inside the subarachnoid space, the bacteria 00:51:43.000 --> 00:51:46.099 multiply rapidly because CSF has no white blood 00:51:46.099 --> 00:51:48.079 cells to fight them off. It's a perfect breeding 00:51:48.079 --> 00:51:50.539 ground. Right. The immune system eventually realizes 00:51:50.539 --> 00:51:53.360 what's happening and triggers a massive systemic 00:51:53.360 --> 00:51:56.260 inflammatory response. Millions of neutrophils 00:51:56.260 --> 00:51:58.920 rush into the CSF. They fight the bacteria and 00:51:58.920 --> 00:52:00.940 the resulting debris forms a thick, purulent 00:52:00.940 --> 00:52:04.059 exudate. Pass. The CSF, which is normally crystal 00:52:04.059 --> 00:52:06.920 clear, becomes this thick, cloudy, infected sludge. 00:52:07.179 --> 00:52:10.710 Exactly. This thick exudate coats the surface 00:52:10.710 --> 00:52:13.289 of the brain. It wraps around and damages the 00:52:13.289 --> 00:52:16.530 cranial nerves. And critically, it physically 00:52:16.530 --> 00:52:19.190 clogs the arachnoid villi. Remind me what the 00:52:19.190 --> 00:52:21.489 arachnoid villi do. They are the structures that 00:52:21.489 --> 00:52:24.469 reabsorb the used CSF back into the venous bloodstream. 00:52:24.750 --> 00:52:27.210 They're the drains for the sink. If the thick 00:52:27.210 --> 00:52:29.929 pus clogs the drains, the brain is still producing 00:52:29.929 --> 00:52:32.929 500 milliliters of CSF a day, but none of it 00:52:32.929 --> 00:52:35.030 can drain out. So you get non -communicating 00:52:35.030 --> 00:52:37.840 hydrocephalus. the sink overflows. The fluid 00:52:37.840 --> 00:52:40.639 builds up, the inflammatory mediators cause massive 00:52:40.639 --> 00:52:43.719 cerebral edema, and the ICP spikes drastically. 00:52:43.860 --> 00:52:46.179 Let's talk assessment. The classic triad we all 00:52:46.179 --> 00:52:48.280 learn in nursing school. Fever, severe headache, 00:52:48.500 --> 00:52:50.699 and neutral rigidity. Neutral rigidity being 00:52:50.699 --> 00:52:53.480 a stiff neck. They physically cannot touch their 00:52:53.480 --> 00:52:55.440 chin to their chest because the meninges are 00:52:55.440 --> 00:52:58.139 so inflamed that stretching them causes excruciating 00:52:58.139 --> 00:53:00.840 pain. Right. For bacterial meningitis specifically, 00:53:00.960 --> 00:53:03.440 you also look for severe photophobia, like it 00:53:03.440 --> 00:53:05.699 hurts their eyes, and a highly specific sign. 00:53:05.900 --> 00:53:10.119 A patechial rash. The tumbler test. Yes. If the 00:53:10.119 --> 00:53:12.599 patient has a rash, press the base of a clear 00:53:12.599 --> 00:53:15.559 drinking glass, a tumbler against the skin. If 00:53:15.559 --> 00:53:18.000 the rash is just normal inflammation, it will 00:53:18.000 --> 00:53:20.079 blanch, meaning it turns white under the pressure. 00:53:20.619 --> 00:53:23.639 But if it's a patechial rash from meningococcal 00:53:23.639 --> 00:53:26.420 meningitis, it will not blanch. You will still 00:53:26.420 --> 00:53:28.460 see the red or purple dots through the glass. 00:53:28.730 --> 00:53:31.449 This is because patechiae are actually tiny micro 00:53:31.449 --> 00:53:33.530 hemorrhages under the skin, not just surface 00:53:33.530 --> 00:53:36.550 inflammation. It is a very bad sign. And how 00:53:36.550 --> 00:53:38.710 does the assessment differ for encephalitis? 00:53:39.010 --> 00:53:41.190 Because encephalitis is inflammation of the brain 00:53:41.190 --> 00:53:43.409 tissue itself, rather than just the fluid around 00:53:43.409 --> 00:53:46.150 it, you see much more pronounced mental status 00:53:46.150 --> 00:53:49.190 changes early on. bizarre behavior, tremors, 00:53:49.510 --> 00:53:51.909 amnesia, camuparesis. It looks a bit more like 00:53:51.909 --> 00:53:54.030 a stroke or a severe psychiatric event initially. 00:53:54.550 --> 00:53:56.869 Okay, diagnostics. This is perhaps the most critical 00:53:56.869 --> 00:53:59.329 safety point in this entire deep dive. To diagnose 00:53:59.329 --> 00:54:01.570 meningitis, we need a sample of the CSF, which 00:54:01.570 --> 00:54:04.829 means a lumbar puncture and LP. But there is 00:54:04.829 --> 00:54:07.789 a mandatory rule before you do an LP. A CT scan 00:54:07.789 --> 00:54:09.949 of the head must be done before a lumbar puncture 00:54:09.949 --> 00:54:12.429 in any patient with suspected increased ICP. 00:54:12.610 --> 00:54:14.550 I really want to understand the physics of why. 00:54:14.880 --> 00:54:17.960 What happens if a doctor just does an LP blindly 00:54:17.960 --> 00:54:20.500 on a patient with a swollen brain? Think about 00:54:20.500 --> 00:54:23.619 the pressure gradient. Inside the skull, the 00:54:23.619 --> 00:54:25.940 pressure is massive. It's pushing downward trying 00:54:25.940 --> 00:54:28.579 to find an exit. But the pressure in the spinal 00:54:28.579 --> 00:54:31.539 column below is also somewhat high, which holds 00:54:31.539 --> 00:54:34.219 the brain in place. If you insert a needle into 00:54:34.219 --> 00:54:36.619 the lower spine and open the system to the room 00:54:36.619 --> 00:54:39.320 air, you instantly drop the pressure in the spinal 00:54:39.320 --> 00:54:42.179 column to zero. You create a vacuum effect. Exactly. 00:54:42.659 --> 00:54:44.940 The massive high pressure in the skull instantly 00:54:44.940 --> 00:54:47.599 takes the path of least resistance. It forces 00:54:47.599 --> 00:54:50.000 the brain tissue violently downward through the 00:54:50.000 --> 00:54:52.579 forum and magnum. You will cause a catastrophic 00:54:52.579 --> 00:54:54.900 fatal brainstem herniation right there on the 00:54:54.900 --> 00:54:57.500 table. You always CT first to rule out a mass 00:54:57.500 --> 00:55:00.039 effect or severe obstruction. Once the CT is 00:55:00.039 --> 00:55:02.239 clear and the LP is done, we analyze the fluid. 00:55:02.579 --> 00:55:04.519 What is the differential pattern between bacterial 00:55:04.519 --> 00:55:08.599 and viral CSF? Bacterial CSF is turbid, cloudy, 00:55:08.860 --> 00:55:11.550 or even purulent. It has a massively high white 00:55:11.550 --> 00:55:13.809 blood cell count, predominantly neutrophils. 00:55:14.269 --> 00:55:17.329 The protein is high, over 500, because the bacteria 00:55:17.329 --> 00:55:20.190 and immune cells are made of protein. And critically, 00:55:20.750 --> 00:55:24.190 the glucose is L... Because the bacteria are 00:55:24.190 --> 00:55:26.190 living organisms and they are literally eating 00:55:26.190 --> 00:55:29.769 the glucose in the fluid for energy. Yes. Viral 00:55:29.769 --> 00:55:32.349 CSF, on the other hand, is usually clear or slightly 00:55:32.349 --> 00:55:34.909 cloudy. The white blood cells are elevated, but 00:55:34.909 --> 00:55:37.750 they are lymphocytes, not neutrophils. The protein 00:55:37.750 --> 00:55:40.130 is only slightly elevated, and the glucose is 00:55:40.130 --> 00:55:42.469 normal because viruses don't eat glucose. From 00:55:42.469 --> 00:55:45.389 an ADPIE perspective assessment, you are doing 00:55:45.389 --> 00:55:47.570 the Tumblr test on any rash and checking for 00:55:47.570 --> 00:55:50.880 neutral rigidity. Diagnosis. Acute pain related 00:55:50.880 --> 00:55:54.480 to meningeal irritation and hyperthermia. Planning. 00:55:54.960 --> 00:55:56.860 Resolve the infection and strictly control the 00:55:56.860 --> 00:55:59.039 fever. For implementation, you keep the room 00:55:59.039 --> 00:56:01.460 dark because of the photophobia. You put a cool 00:56:01.460 --> 00:56:03.659 cloth over their eyes. You minimize all stimuli. 00:56:03.840 --> 00:56:06.539 No loud TVs. No constant alarms if possible. 00:56:06.619 --> 00:56:08.880 Restrict visitors. The inflamed brain is hyper 00:56:08.880 --> 00:56:10.840 -excitable and excess stimulation can easily 00:56:10.840 --> 00:56:13.090 trigger a seizure. Let's talk priority nursing 00:56:13.090 --> 00:56:15.150 actions because this is life or death for the 00:56:15.150 --> 00:56:18.190 patient and the staff. A patient rolls in with 00:56:18.190 --> 00:56:22.409 the triad. Fever, headache, stiff neck. What 00:56:22.409 --> 00:56:25.889 is my first, next T, and then? First, respiratory 00:56:25.889 --> 00:56:28.789 isolation. Immediately. droplet precautions, 00:56:29.190 --> 00:56:31.550 mask, gown, gloves for everyone entering the 00:56:31.550 --> 00:56:33.710 room. You keep them in isolation until the cultures 00:56:33.710 --> 00:56:35.809 come back negative or they've been on targeted 00:56:35.809 --> 00:56:38.250 antibiotics for 24 hours. Protect the unit first. 00:56:38.289 --> 00:56:41.130 What is NEXT -T? NEXT -T draw blood cultures 00:56:41.130 --> 00:56:44.590 and prep them for the CT and LP and then administer 00:56:44.590 --> 00:56:47.570 Empiric -5E antibiotics immediately. Wait, immediately 00:56:47.570 --> 00:56:50.230 before the LP results come back? Yes, you draw 00:56:50.230 --> 00:56:51.929 the blood cultures first so the antibiotics don't 00:56:51.929 --> 00:56:54.369 ruin the blood sample. But you do not wait for 00:56:54.369 --> 00:56:57.460 the LP results to start the IV antibiotics. Meningitis 00:56:57.460 --> 00:57:00.320 duplicates incredibly fast. Every hour you delay 00:57:00.320 --> 00:57:02.739 antibiotics, the mortality rate jumps, blasts 00:57:02.739 --> 00:57:05.099 them with broad spectrum antibiotics like ceftriaxone 00:57:05.099 --> 00:57:08.360 or ampicillin immediately. Meads, we use a cyclover 00:57:08.360 --> 00:57:11.340 for HSV encephalitis. Yes, and you must start 00:57:11.340 --> 00:57:13.420 it early before the patient falls into a coma 00:57:13.420 --> 00:57:16.420 for it to have maximum benefit. It limits viral 00:57:16.420 --> 00:57:19.099 replication. For pain control and meningitis, 00:57:19.300 --> 00:57:21.360 the headaches are described as the worst of their 00:57:21.360 --> 00:57:24.969 life. Why do we often use codeine? Coding provides 00:57:24.969 --> 00:57:27.769 significant pain relief, but it does not alter 00:57:27.769 --> 00:57:30.530 the level of consciousness as profoundly as IV 00:57:30.530 --> 00:57:33.090 fentanyl or morphine. We need to be able to wake 00:57:33.090 --> 00:57:35.389 them up and track their neuro status accurately. 00:57:35.710 --> 00:57:38.230 Hemodynamics and fluids. We have to watch for 00:57:38.230 --> 00:57:40.670 septic shock dynamics, especially with meningococcal 00:57:40.670 --> 00:57:43.510 infections. But I want to talk about fluid replacement. 00:57:43.809 --> 00:57:46.750 These patients have fevers of 103, 104 degrees. 00:57:47.130 --> 00:57:50.110 They are sweating profusely. How do we calculate 00:57:50.110 --> 00:57:53.050 fluid replacement for hypermetabolism? As a baseline 00:57:53.050 --> 00:57:55.449 rule of thumb, you calculate 800 milliliters 00:57:55.449 --> 00:57:57.949 per day for normal respiratory and insensible 00:57:57.949 --> 00:58:00.809 losses. Then you add 100 milliliters for every 00:58:00.809 --> 00:58:02.690 single degree of temperature over 38 degrees 00:58:02.690 --> 00:58:05.969 Celsius, or 100 .4 Fahrenheit. They're losing 00:58:05.969 --> 00:58:08.369 massive amounts of free water through hypermetabolism 00:58:08.369 --> 00:58:10.070 and diaphoresis. And if you don't replace it, 00:58:10.369 --> 00:58:12.610 they will become severely hypovolemic, which 00:58:12.610 --> 00:58:15.070 drops their MAP, which drops their CPP, which 00:58:15.070 --> 00:58:17.570 kills the brain. Let's talk about the most terrifying 00:58:17.570 --> 00:58:19.849 complication, Waterhouse -Friedrichsen syndrome. 00:58:20.059 --> 00:58:22.780 It is a devastating complication of meningococcal 00:58:22.780 --> 00:58:25.480 meningitis. The massive bacterial load in the 00:58:25.480 --> 00:58:28.139 blood causes disseminated intravascular coagulation, 00:58:28.539 --> 00:58:31.699 or DIC. They start clotting everywhere, consuming 00:58:31.699 --> 00:58:33.980 all their platelets, and then they start bleeding 00:58:33.980 --> 00:58:36.380 from everywhere. Which is why we see the patechial 00:58:36.380 --> 00:58:40.340 rash. Right. But worse, it causes bilateral adrenal 00:58:40.340 --> 00:58:42.880 hemorrhage. The adrenal glands bleed out and 00:58:42.880 --> 00:58:45.699 fail. Without cortisol, the patient loses all 00:58:45.699 --> 00:58:48.780 vascular tone and goes into profound treatment 00:58:48.780 --> 00:58:51.280 -resistant circulatory collapse. So the patient 00:58:51.280 --> 00:58:53.599 is getting worse if their patechial rash is rapidly 00:58:53.599 --> 00:58:56.139 spreading across their torso or if they develop 00:58:56.139 --> 00:58:58.440 a cranial nerve palsy like a drooping eyelid 00:58:58.440 --> 00:59:01.460 or a blown pupa signaling brainstem compression. 00:59:01.760 --> 00:59:04.219 And the escalation protocol is a code or immediate 00:59:04.219 --> 00:59:06.760 intervention if you see signs of DIC and shock. 00:59:06.920 --> 00:59:09.780 dropping blood pressure, oozing from IV sites, 00:59:10.059 --> 00:59:12.539 spreading petechiae. Here is a major ICU pearl 00:59:12.539 --> 00:59:15.079 regarding fever management. We said fever spikes 00:59:15.079 --> 00:59:16.860 the metabolic demand in the ICP, so I should 00:59:16.860 --> 00:59:18.559 just pack them in ice and put a cooling blanket 00:59:18.559 --> 00:59:21.539 on maximum right. Absolutely not. You must treat 00:59:21.539 --> 00:59:23.760 the fever vigorously, but you must not reduce 00:59:23.760 --> 00:59:26.460 it too rapidly. If you use a cooling blanket 00:59:26.460 --> 00:59:29.099 and you drop the skin temperature too fast, the 00:59:29.099 --> 00:59:31.360 hypothalamus panics and triggers violent shivering. 00:59:31.530 --> 00:59:34.650 Shivering generates heat, but it also massively 00:59:34.650 --> 00:59:36.889 increases the metabolic demand for oxygen, which 00:59:36.889 --> 00:59:39.510 will instantly spike the ICP. So how do we prevent 00:59:39.510 --> 00:59:42.170 it? You wrap their extremities, their hands and 00:59:42.170 --> 00:59:44.510 feet in soft towels to keep the peripheral receptors 00:59:44.510 --> 00:59:47.329 warm and trick the brain, while you apply the 00:59:47.329 --> 00:59:50.309 cooling blanket to their core, and you give acetaminophen. 00:59:50.730 --> 00:59:52.869 Intensivist thinking for infections. Problem. 00:59:53.119 --> 00:59:55.380 A college student presents with a stiff neck, 00:59:55.639 --> 00:59:58.659 photophobia, and a non -blanching rash. Threat. 00:59:58.920 --> 01:00:01.280 Highly contagious meningococcal infection leading 01:00:01.280 --> 01:00:04.119 to intravascular coagulation, adrenal failure, 01:00:04.219 --> 01:00:07.579 and lethal ICP spikes. Intervention. Immediate 01:00:07.579 --> 01:00:10.360 droplet isolation, aggressive fluid resuscitation, 01:00:10.760 --> 01:00:13.320 draw blood cultures, and administer empiric IV 01:00:13.320 --> 01:00:15.840 antibiotics without waiting for the LP reassessment. 01:00:16.440 --> 01:00:18.699 Monitor for spreading rash, worsening hemodynamics, 01:00:18.820 --> 01:00:20.559 and signs of herniation. If you remember only 01:00:20.559 --> 01:00:24.400 five things for neuro infections. 1. Core patho. 01:00:24.739 --> 01:00:26.880 Purulent exudate blocks the arachnoid villi, 01:00:27.119 --> 01:00:30.260 preventing CSF drainage and causing massive ICP 01:00:30.260 --> 01:00:33.519 spikes. 2. Key assessment. Neutral rigidity, 01:00:33.739 --> 01:00:36.219 severe headache, photophobia, and a non -blanching 01:00:36.219 --> 01:00:40.320 patechial rash. 3. Most dangerous complication. 01:00:40.800 --> 01:00:43.460 Herniation from doing an LP without a CT scan 01:00:43.460 --> 01:00:47.349 or waterhouse Fredrickson shock. 4. Priority 01:00:47.349 --> 01:00:49.949 nursing action. Initiate droplet isolation immediately 01:00:49.949 --> 01:00:52.389 and administer empiric antibiotics the second 01:00:52.389 --> 01:00:54.829 cultures are drawn. Number five. Most important 01:00:54.829 --> 01:00:57.389 treatment. Four antibiotics and dexamethasone 01:00:57.389 --> 01:00:59.869 to reduce the inflammation. And your one -sentence 01:00:59.869 --> 01:01:02.110 clinical picture. A young adult presenting with 01:01:02.110 --> 01:01:04.510 a stiff neck, blinding headache, and a patechial 01:01:04.510 --> 01:01:07.250 rash who requires immediate isolation and aggressive 01:01:07.250 --> 01:01:10.019 antibiotic therapy. Action trigger. If you see 01:01:10.019 --> 01:01:12.559 a patient with suspected meningitis, think highly 01:01:12.559 --> 01:01:15.119 contagious medical emergency and do place them 01:01:15.119 --> 01:01:17.199 in isolation before doing anything else. That 01:01:17.199 --> 01:01:19.579 really covers the landscape. We've gone from 01:01:19.579 --> 01:01:22.099 the elegant but unforgiving physics of the Monroe 01:01:22.099 --> 01:01:24.940 Kelly doctrine and the Pax suitcase. We've walked 01:01:24.940 --> 01:01:27.000 through the violent disruption of traumatic brain 01:01:27.000 --> 01:01:28.920 injury and the tragedy of the lucid interval. 01:01:29.380 --> 01:01:32.219 We've explored the insidious slow expansion of 01:01:32.219 --> 01:01:35.039 tumors defeating the compliance curve all the 01:01:35.039 --> 01:01:38.039 way to the toxic, purulent siege of bacterial 01:01:38.039 --> 01:01:40.679 infections. It is a massive amount of information 01:01:40.679 --> 01:01:43.780 to process. But applying that 80 -20 intensivist 01:01:43.780 --> 01:01:47.139 lens, Always asking why the physiology is failing 01:01:47.139 --> 01:01:49.119 at a cellular level and what is going to kill 01:01:49.119 --> 01:01:52.159 the patient really cuts through the noise. You 01:01:52.159 --> 01:01:54.380 aren't just memorizing waveforms. You are understanding 01:01:54.380 --> 01:01:57.099 that a rising P2 waves means the brain has lost 01:01:57.099 --> 01:01:59.420 its stretch. You aren't just memorizing Cushing's 01:01:59.420 --> 01:02:01.619 triad. You are visualizing the crushed medulla 01:02:01.619 --> 01:02:04.099 desperately trying to pump blood into a pressurized 01:02:04.099 --> 01:02:06.949 vault. Exactly. And I want to remind you, our 01:02:06.949 --> 01:02:08.849 listener, of your incredibly unique position 01:02:08.849 --> 01:02:11.690 in the healthcare team. In the ICU, the brain 01:02:11.690 --> 01:02:14.210 cannot advocate for itself. The monitors beep, 01:02:14.289 --> 01:02:17.269 the numbers flash, but they do not provide context. 01:02:17.670 --> 01:02:20.329 The context relies entirely on your vigilance. 01:02:20.690 --> 01:02:23.110 Your ability to translate a subtle two -second 01:02:23.110 --> 01:02:25.809 delay in answering a question into life -saving 01:02:25.809 --> 01:02:28.710 osmotic therapy is what stands between the patient 01:02:28.710 --> 01:02:31.630 and secondary brain death. You are the ultimate 01:02:31.630 --> 01:02:34.679 translator of that black box. So all said. So 01:02:34.679 --> 01:02:36.519 what does this all mean? I want to leave you 01:02:36.519 --> 01:02:38.260 with a final thought to mull over as you head 01:02:38.260 --> 01:02:40.599 into your next shift. We spend our whole lives 01:02:40.599 --> 01:02:43.300 trying to expand our minds, right? Reading, learning, 01:02:43.480 --> 01:02:46.039 experiencing new things, growing. But in the 01:02:46.039 --> 01:02:48.659 neuro ICU, a mind that expands is a mind that 01:02:48.659 --> 01:02:51.880 dies. The human skull is an exclusive VIP club, 01:02:51.960 --> 01:02:54.340 and it has a strictly enforced capacity limit. 01:02:54.760 --> 01:02:56.820 As an intensivist level nurse, your ultimate 01:02:56.820 --> 01:02:58.739 job isn't just treating the disease or hanging 01:02:58.739 --> 01:03:00.840 the antibiotics. It's playing bouncer at the 01:03:00.840 --> 01:03:03.260 door of the form and magnum. Keep the pressure 01:03:03.260 --> 01:03:05.860 controlled. Keep the swelling down. and keep 01:03:05.860 --> 01:03:07.639 the brain exactly where it belongs.