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 --> 00:00:43.280 room. You know, usually when we think about intensive 00:00:43.280 --> 00:00:47.130 care sedation, we kind of picture a light switch. 00:00:47.429 --> 00:00:49.770 You give a drug, the switch flips, and the patient 00:00:49.770 --> 00:00:52.250 is just completely plunged into darkness. Right, 00:00:52.350 --> 00:00:55.070 yeah. It's binary. You administer something like, 00:00:55.070 --> 00:00:57.890 I don't know, a heavy propofol drip. And there's 00:00:57.890 --> 00:01:00.350 really no middle ground. Yeah, exactly. There's 00:01:00.350 --> 00:01:02.990 no respiratory drive left, no ability for the 00:01:02.990 --> 00:01:05.950 patient to follow commands. As the medical team, 00:01:06.049 --> 00:01:09.849 we are basically taking total absolute control 00:01:09.849 --> 00:01:12.409 of their physiology. And functionally, that is 00:01:12.409 --> 00:01:15.049 exactly what we have needed a lot of the time. 00:01:15.650 --> 00:01:17.950 But then you encounter a medication that doesn't 00:01:17.950 --> 00:01:21.590 just flip the switch. It's like it installs a 00:01:21.590 --> 00:01:23.989 highly sophisticated dimmer. Oh, I like that. 00:01:24.049 --> 00:01:26.109 A dimmer switch. Yeah, one that actually lets 00:01:26.109 --> 00:01:28.349 you talk to the patient while they're on it without 00:01:28.349 --> 00:01:31.310 sacrificing their comfort. Which, I mean, that 00:01:31.310 --> 00:01:33.489 fundamentally changes the entire landscape of 00:01:33.489 --> 00:01:36.310 critical care. You are no longer flying blind 00:01:36.310 --> 00:01:38.769 with your neurological assessments. You don't 00:01:38.769 --> 00:01:40.629 have to guess what's happening in the brain because 00:01:40.629 --> 00:01:43.069 you can actually just ask the patient. Exactly, 00:01:43.489 --> 00:01:45.689 and that is exactly what we're getting into today 00:01:45.689 --> 00:01:49.129 on this deep dive. We are tossing out the textbook 00:01:49.129 --> 00:01:52.189 fluff and acting as your elite critical care 00:01:52.189 --> 00:01:55.969 pharmacology instructors to break down a genuinely 00:01:55.969 --> 00:02:00.430 fascinating vital medication, which is dexmedatomidine. 00:02:00.590 --> 00:02:02.450 Right, which most of you probably know better 00:02:02.450 --> 00:02:06.170 as Presodex. Yes, Presodex. We are aggressively 00:02:06.170 --> 00:02:08.909 applying the 80 -20 Pareto principle here. So 00:02:08.909 --> 00:02:10.849 we're cutting through the noise to focus strictly 00:02:10.849 --> 00:02:13.569 on the highest yield clinical facts. The 20 % 00:02:13.569 --> 00:02:16.490 of info that gives you 80 % of the results. Exactly. 00:02:16.729 --> 00:02:19.150 The core mechanics of why it's chosen and the 00:02:19.150 --> 00:02:20.849 pearls you actually need to keep your patients 00:02:20.849 --> 00:02:23.949 safe and ace your board exams. Because when you're 00:02:23.949 --> 00:02:26.009 dealing with critical care drugs, information 00:02:26.009 --> 00:02:28.389 overload is genuinely dangerous. Yeah. You know, 00:02:28.430 --> 00:02:30.169 you need to understand what a drug does to the 00:02:30.169 --> 00:02:32.969 body and exactly how it can turn on you if you 00:02:32.969 --> 00:02:34.849 aren't paying attention. Okay, let's unpack this. 00:02:35.289 --> 00:02:37.310 Dexminatomidine is fundamentally known as a unique 00:02:37.310 --> 00:02:39.930 sedative used in the ICU, but as I was looking 00:02:39.930 --> 00:02:41.849 through our source material, it has some, like, 00:02:42.050 --> 00:02:44.270 highly surprising formulations and uses completely 00:02:44.270 --> 00:02:46.789 outside the ICU, too. Oh, absolutely. It's wild. 00:02:47.020 --> 00:02:49.340 But before we get into how to give it or when 00:02:49.340 --> 00:02:51.460 to hold it, we need to understand the underlying 00:02:51.460 --> 00:02:54.539 machinery. So what is this drug actually doing 00:02:54.539 --> 00:02:58.439 in the brain? Well, at its core, dexmitetamidine 00:02:58.439 --> 00:03:01.419 is a relatively selective, centrally acting alpha 00:03:01.419 --> 00:03:05.020 -2 adrenergic agonist. Okay, that is a mouthful. 00:03:05.139 --> 00:03:07.500 I know, I know. So let's translate that into 00:03:07.500 --> 00:03:09.819 how it actually creates a physiologic effect. 00:03:10.460 --> 00:03:12.360 It works in the nervous system in two main ways. 00:03:14.159 --> 00:03:16.280 presynaptically and postsynaptically. Let's break 00:03:16.280 --> 00:03:18.520 those down. What is happening on the presynaptic 00:03:18.520 --> 00:03:20.960 side? So presynaptic activation of these alpha 00:03:20.960 --> 00:03:23.300 -2 receptors essentially acts as a break on the 00:03:23.300 --> 00:03:25.680 release of norepinephrine. Nohoma pinifera is 00:03:25.680 --> 00:03:27.939 like the gas pedal, right? Right. It's a major 00:03:27.939 --> 00:03:30.539 excitatory neurotransmitter. So if you block 00:03:30.539 --> 00:03:33.419 its release, you are effectively terminating 00:03:33.419 --> 00:03:35.879 the propagation of pain signals before they can 00:03:35.879 --> 00:03:37.960 even travel further. Oh, wow. Yeah. That gives 00:03:37.960 --> 00:03:39.860 you your analgesic effect. So it's stopping the 00:03:39.860 --> 00:03:41.639 pain signal from being handed off to the next 00:03:41.639 --> 00:03:44.500 nerve. And then what about the postsynaptic side? 00:03:44.759 --> 00:03:47.080 Post synaptic activation in the central nervous 00:03:47.080 --> 00:03:49.780 system inhibits general sympathetic activity. 00:03:50.240 --> 00:03:52.580 It just drops your overall sympathetic tone. 00:03:52.599 --> 00:03:55.099 OK, got it. And when the sympathetic nervous 00:03:55.099 --> 00:03:57.659 system, you know, your fight or flight system 00:03:57.659 --> 00:04:00.740 powers down, that leads directly to a decreased 00:04:00.740 --> 00:04:03.120 blood pressure and a decreased heart rate. So 00:04:03.120 --> 00:04:05.379 the end result of manipulating both of those 00:04:05.379 --> 00:04:09.120 receptors is sedation, analgesia. So. pain relief, 00:04:09.360 --> 00:04:11.620 and anxiolysis. Right, which is a massive reduction 00:04:11.620 --> 00:04:13.960 in anxiety. I always like to picture this mechanism 00:04:13.960 --> 00:04:16.839 like a really effective professional bouncer 00:04:16.839 --> 00:04:19.600 at a chaotic nightclub. OK, let's hear it. So 00:04:19.600 --> 00:04:22.540 the central nervous system is the club. Dexmitatomidine 00:04:22.540 --> 00:04:25.199 is the bouncer. But instead of aggressively kicking 00:04:25.199 --> 00:04:27.399 people out, throwing punches, and causing a massive 00:04:27.399 --> 00:04:31.220 scene, this bouncer just quietly turns down the 00:04:31.220 --> 00:04:33.500 music. That's the post -synaptic sympathetic 00:04:33.500 --> 00:04:36.439 drop. Exactly. And at the same time, he stops 00:04:36.439 --> 00:04:39.800 letting new, rowdy guests inside. Those rowdy 00:04:39.800 --> 00:04:42.139 guests are the norepinephrine. By just stopping 00:04:42.139 --> 00:04:44.420 the influx of chaos, the whole place naturally 00:04:44.420 --> 00:04:46.860 calms down. That is a highly accurate way to 00:04:46.860 --> 00:04:49.279 visualize it. And if we want to look at the... 00:04:50.110 --> 00:04:52.569 the deep pharmacology of where this bouncer is 00:04:52.569 --> 00:04:55.490 standing. The drug is working heavily in a specific 00:04:55.490 --> 00:04:57.949 part of the brainstem called the locus carulius. 00:04:58.069 --> 00:05:00.470 This is carulius, okay. Yeah, that area is the 00:05:00.470 --> 00:05:03.170 brain's predominant nor -genergic center. It's 00:05:03.170 --> 00:05:05.129 basically the panic and wakefulness headquarters. 00:05:06.649 --> 00:05:09.389 Dexmitetamidine activates specific G -protein 00:05:09.389 --> 00:05:11.970 -gated channels there. Which does what, exactly? 00:05:11.990 --> 00:05:14.649 To put it simply, it opens cellular exit doors, 00:05:14.769 --> 00:05:17.629 letting potassium leak out of the neuron. This 00:05:17.629 --> 00:05:20.149 makes the neuron too negatively charged to fire 00:05:20.149 --> 00:05:23.110 and stops it from releasing more neurotransmitters. 00:05:23.629 --> 00:05:26.709 It is a profoundly targeted, elegant mechanism. 00:05:26.870 --> 00:05:28.670 But wait, I have to push back here for a second. 00:05:28.810 --> 00:05:31.189 When you say centrally acting alpha -2 agonist, 00:05:31.329 --> 00:05:33.610 my brain immediately goes to clonidine. Sure. 00:05:33.750 --> 00:05:35.050 Yeah, that makes sense. We use clondine all the 00:05:35.050 --> 00:05:37.069 time for blood pressure, sometimes for withdrawal 00:05:37.069 --> 00:05:40.230 or anxiety. So is dexamidatomidane just a much 00:05:40.230 --> 00:05:42.670 more expensive intravenous version of clonidine? 00:05:42.850 --> 00:05:44.870 That is the exact logical leap a lot of people 00:05:44.870 --> 00:05:47.490 make. But no, it is not. And the distinction 00:05:47.490 --> 00:05:50.850 is a major clinical pearl here. Dexmitetomidine 00:05:50.850 --> 00:05:53.790 is eight times more specific for alpha -2 receptors 00:05:53.790 --> 00:05:56.480 than clonidine. Eight times more specific. What 00:05:56.480 --> 00:05:58.000 does that actually look like in the numbers? 00:05:58.180 --> 00:06:00.800 The activity ratio of alpha -2 to alpha -1 for 00:06:00.800 --> 00:06:05.439 dexmedetomidine is a staggering 1 ,620 to 1. 00:06:05.519 --> 00:06:08.600 Whoa. Yeah. For clonidine, it's only 220 to 1. 00:06:08.959 --> 00:06:12.360 1 ,620 to 1. That specificity is just, I mean, 00:06:12.519 --> 00:06:15.420 it's wild. Exactly. It means dexmedetomidine 00:06:15.420 --> 00:06:18.220 is acting with absolute pinpoint precision on 00:06:18.220 --> 00:06:21.230 those alpha -2 receptors. Because it is so specific, 00:06:21.430 --> 00:06:24.310 it gives us profound sedation and analgesia without 00:06:24.310 --> 00:06:26.649 broadly hitting other receptors that might trigger 00:06:26.649 --> 00:06:28.610 unwanted side effects. Well, at least until you 00:06:28.610 --> 00:06:30.769 start pushing massive, massive doses. Right, 00:06:30.910 --> 00:06:32.709 exactly. Knowing that it acts with that kind 00:06:32.709 --> 00:06:35.170 of 1600 to 1 precision, it begs the question, 00:06:35.170 --> 00:06:37.029 you know, why isn't this the default for every 00:06:37.029 --> 00:06:39.009 single patient? Why are providers still reaching 00:06:39.009 --> 00:06:42.230 for propofol or benzodiazepines if this mechanism 00:06:42.230 --> 00:06:44.560 is so elegant? It really comes down to what you 00:06:44.560 --> 00:06:47.199 actually need the patient to do. In the intensive 00:06:47.199 --> 00:06:49.959 care unit, the primary use is for sedation induction 00:06:49.959 --> 00:06:52.480 and maintenance in mechanically ventilated patients. 00:06:52.800 --> 00:06:55.279 We're talking adults, children, and neonates. 00:06:55.480 --> 00:06:57.420 And for procedural sedation too, right? Yep, 00:06:57.439 --> 00:06:59.920 that too. But the defining reason a provider 00:06:59.920 --> 00:07:03.360 chooses it over a benzo or propofol, the ultimate 00:07:03.360 --> 00:07:06.199 why choose this drug takeaway, is that it provides 00:07:06.199 --> 00:07:09.579 what we call arousable sedation. Arousable sedation. 00:07:09.759 --> 00:07:12.240 Yes. And it has extremely limited effects on 00:07:12.240 --> 00:07:14.839 the central respiratory drive. In fact, clinical 00:07:14.839 --> 00:07:17.839 guidelines explicitly recommend nonbenzodiazepine 00:07:17.839 --> 00:07:21.879 sedatives like dexmititomidine over benzodiazepines 00:07:21.879 --> 00:07:24.360 for mechanically ventilated patients in non -cardiac 00:07:24.360 --> 00:07:26.519 surgery. Specifically because it reduces the 00:07:26.519 --> 00:07:29.959 need for other heavy painkillers, right? I have 00:07:29.959 --> 00:07:32.990 to pause on that phrase, though. Arousable sedation. 00:07:33.250 --> 00:07:35.790 Honestly, it sounds like an oxymoron. If a patient 00:07:35.790 --> 00:07:38.129 is deeply sedated enough to tolerate a breathing 00:07:38.129 --> 00:07:40.589 tube, how are they arousable? Aren't those two 00:07:40.589 --> 00:07:43.230 states mutually exclusive? It does sound contradictory 00:07:43.230 --> 00:07:47.970 until you see it happen in the room. With heavy 00:07:47.970 --> 00:07:50.709 anesthetics, the patient is totally unresponsive. 00:07:51.470 --> 00:07:53.769 You perform a sternal rub or call their name, 00:07:53.970 --> 00:07:57.050 and you get very little, if any, purposeful response. 00:07:57.269 --> 00:08:00.029 They're just locked away. Exactly. But a patient 00:08:00.029 --> 00:08:02.689 on a dexmedetomidang drip is entirely different. 00:08:03.230 --> 00:08:05.529 You can walk into the ICU room, call their name, 00:08:05.750 --> 00:08:08.310 and they will calmly open their eyes. Oh, really? 00:08:08.569 --> 00:08:10.550 Yeah, they can follow complex commands for a 00:08:10.550 --> 00:08:12.870 neurological check, like, squeeze my hands, wiggle 00:08:12.870 --> 00:08:15.769 your toes, look up. And the moment you stop stimulating 00:08:15.769 --> 00:08:18.069 them and step back, they just peacefully drift 00:08:18.069 --> 00:08:20.230 right back to sleep. Going back to that dimmer 00:08:20.230 --> 00:08:22.620 switch analogy. You just dial up the lights for 00:08:22.620 --> 00:08:24.720 30 seconds, do your neuro -assessment, ensure 00:08:24.720 --> 00:08:27.000 their brain is functioning properly, and then 00:08:27.000 --> 00:08:29.100 dial the lights back down. Which is invaluable 00:08:29.100 --> 00:08:31.740 in neurocritical care. I can't imagine. But what 00:08:31.740 --> 00:08:34.519 about outside the ICU? Because the sources show 00:08:34.519 --> 00:08:36.600 some genuinely surprising formulations that I 00:08:36.600 --> 00:08:38.399 wasn't expecting for an intensive care drug. 00:08:38.740 --> 00:08:40.139 Oh, this is where it gets really innovative. 00:08:40.539 --> 00:08:42.820 What's fascinating here is they've actually developed 00:08:42.820 --> 00:08:47.080 a sublingual and buckle film formulation. The 00:08:47.080 --> 00:08:50.299 brand name is Igalmi. And this isn't for putting 00:08:50.299 --> 00:08:52.480 someone on a ventilator, right? No, not at all. 00:08:52.820 --> 00:08:54.799 This formulation is specifically used for the 00:08:54.799 --> 00:08:57.039 treatment of acute agitation associated with 00:08:57.039 --> 00:09:01.580 schizophrenia, or bipolar two disorder in adults. 00:09:01.720 --> 00:09:04.500 Wait, a film? Like one of those dissolving breath 00:09:04.500 --> 00:09:07.059 strips? Exactly like that. It's a dissolving 00:09:07.059 --> 00:09:10.440 film that delivers the drug right into the bloodstream 00:09:10.440 --> 00:09:13.149 through the mucosa of the mouth. Okay. That makes 00:09:13.149 --> 00:09:15.610 sense. Think about the clinical reality of a 00:09:15.610 --> 00:09:18.649 psychiatric emergency. Trying to start a traditional 00:09:18.649 --> 00:09:22.509 IV on a patient with severe acute agitation is 00:09:22.509 --> 00:09:25.049 incredibly dangerous. Yeah, for both the patient 00:09:25.049 --> 00:09:27.409 and the health care staff. Right. And if you 00:09:27.409 --> 00:09:30.029 inject them with heavy typical antipsychotics 00:09:30.029 --> 00:09:33.529 or massive doses of benzodiazepines, you risk 00:09:33.529 --> 00:09:35.529 knocking out the respiratory drive entirely. 00:09:35.649 --> 00:09:37.909 So you're bypassing the needle, getting a fast 00:09:37.909 --> 00:09:40.590 onset through the mucosa, and preserving their 00:09:40.590 --> 00:09:42.950 drive to breathe while still bringing their sympathetic 00:09:42.950 --> 00:09:45.370 nervous system back down to a manageable level. 00:09:45.750 --> 00:09:47.909 Right. And we are seeing other off -label uses 00:09:47.909 --> 00:09:50.889 emerge, too. For example, intranasal administration 00:09:50.889 --> 00:09:54.210 for pediatric procedural or pre -anesthesia sedation. 00:09:54.350 --> 00:09:56.850 Oh, intranasal. Yeah, they literally just drip 00:09:56.850 --> 00:09:59.190 the liquid into a child's nostrils 30 to 60 minutes 00:09:59.190 --> 00:10:02.169 before procedure. No traumatic fa 'vi start required. 00:10:02.350 --> 00:10:05.190 That is brilliant. Anything to avoid traumatizing 00:10:05.190 --> 00:10:07.409 a kid with a needle before surgery. We're even 00:10:07.409 --> 00:10:10.210 seeing continuous IV infusions use off label 00:10:10.210 --> 00:10:12.750 for severe alcohol withdrawal, allowing us to 00:10:12.750 --> 00:10:14.929 manage those brutal withdrawal symptoms without 00:10:14.929 --> 00:10:17.129 suppressing their breathing. But look, arousable 00:10:17.129 --> 00:10:19.950 sedation and magical dissolving films sound perfect 00:10:19.950 --> 00:10:23.350 on paper. The reality is we are actively and 00:10:23.350 --> 00:10:25.470 aggressively manipulating the sympathetic nervous 00:10:25.470 --> 00:10:28.049 system. Yeah, we are. That has to come with serious 00:10:28.049 --> 00:10:30.870 risks. Let's look at the complications. This 00:10:30.870 --> 00:10:32.649 is what we need to think. logically about what 00:10:32.649 --> 00:10:35.389 we are doing to the body. Following our reasoning 00:10:35.389 --> 00:10:37.909 pattern, if the mechanism is sympathetic and 00:10:37.909 --> 00:10:40.649 the physiologic effect decreases sympathetic 00:10:40.649 --> 00:10:43.169 tone, what is the inevitable cost? The heart 00:10:43.169 --> 00:10:46.509 slows down and the blood vessels relax. Precisely. 00:10:46.769 --> 00:10:49.950 Therefore, the most dangerous logical adverse 00:10:49.950 --> 00:10:54.309 effects are severe bradycardia and severe hypotension. 00:10:54.549 --> 00:10:56.649 And the numbers on this in the literature are 00:10:56.649 --> 00:10:59.029 no joke. The source data shows the incidence 00:10:59.029 --> 00:11:02.450 of hypotension can be up to 56%. Bradycardia 00:11:02.450 --> 00:11:05.590 can hit 62 % of patients. More than half. Yeah, 00:11:05.690 --> 00:11:08.350 more than half. Those are your absolute priority 00:11:08.350 --> 00:11:11.350 safety parameters to monitor. But here's where 00:11:11.350 --> 00:11:13.789 it gets really interesting. As I was reading 00:11:13.789 --> 00:11:16.710 through the pharmacology data, I found a massive 00:11:16.710 --> 00:11:19.929 physiological paradox. Oh, the IV push paradox. 00:11:20.129 --> 00:11:23.450 Yes. If you give this drug via a rapid IV push, 00:11:23.809 --> 00:11:26.230 it actually causes transient hypertension, high 00:11:26.230 --> 00:11:28.649 blood pressure, followed immediately by severe 00:11:28.649 --> 00:11:31.789 reflex bradycardia. How does a drug designed 00:11:31.789 --> 00:11:34.110 to lower blood pressure suddenly cause it to 00:11:34.110 --> 00:11:36.509 spike? It is a brilliant paradox. And it all 00:11:36.509 --> 00:11:38.490 comes back to receptor location and the speed 00:11:38.490 --> 00:11:40.610 of delivery. Remember, earlier we said it's a 00:11:40.610 --> 00:11:42.190 centrally acting drug. Right. It's supposed to 00:11:42.190 --> 00:11:44.269 work in the brain. But if you slam it into a 00:11:44.269 --> 00:11:47.649 vein as a rapid IV push, a massive, highly concentrated 00:11:47.649 --> 00:11:50.149 bolus of the drug travels up the arm and hits 00:11:50.149 --> 00:11:51.830 the peripheral blood vessels first. Before it 00:11:51.830 --> 00:11:54.250 even gets to the brain. Long before it ever crosses 00:11:54.250 --> 00:11:57.539 the blood -brain barrier. And in the periphery, 00:11:57.820 --> 00:12:00.679 those massive doses activate alpha -2 receptors 00:12:00.679 --> 00:12:03.500 on the vascular smooth muscle itself. OK, so 00:12:03.500 --> 00:12:05.940 it hits the vessels first. Right. When those 00:12:05.940 --> 00:12:08.179 peripheral receptors get flooded, they cause 00:12:08.179 --> 00:12:10.559 the blood vessels to acutely and violently clamp 00:12:10.559 --> 00:12:13.879 down. That intense constriction is your sudden 00:12:13.879 --> 00:12:17.000 hypertension. So the pipes suddenly shrink. The 00:12:17.000 --> 00:12:19.100 pressure shoots up and then the body panics. 00:12:19.399 --> 00:12:21.779 Exactly. Your body's baroreceptors, the pressure 00:12:21.779 --> 00:12:24.019 sensors in your carotid arteries, they sense 00:12:24.019 --> 00:12:26.220 that sudden, dangerous spike in blood pressure. 00:12:27.080 --> 00:12:29.759 They sound the alarm. set a signal down the vagus 00:12:29.759 --> 00:12:32.259 nerve, and tell the heart to reflexively slam 00:12:32.259 --> 00:12:34.159 on the brakes to compensate for the high pressure. 00:12:34.220 --> 00:12:36.919 Oh, wow. Yeah, that's a severe reflex bradycardia. 00:12:37.279 --> 00:12:40.440 It's a dual -threat hemodynamic crisis, and it 00:12:40.440 --> 00:12:42.659 is caused entirely by the provider pushing the 00:12:42.659 --> 00:12:44.600 drug too fast. That completely connects the dots. 00:12:44.659 --> 00:12:46.899 It's not just an arbitrary nursing rule to memorize. 00:12:47.059 --> 00:12:49.340 You know, the underlying physiology literally 00:12:49.340 --> 00:12:51.720 demands that you go slow or you will crash your 00:12:51.720 --> 00:12:54.220 patient. Speaking of rules and apparent contradictions, 00:12:54.259 --> 00:12:55.899 I found another one in the text that we need 00:12:55.899 --> 00:12:59.710 to clear up. The source explicitly states, dexmitetamidine 00:12:59.710 --> 00:13:02.629 has limited effects on respiratory drive. Which 00:13:02.629 --> 00:13:05.409 is true. Right, as we discussed, that is a massive 00:13:05.409 --> 00:13:09.250 selling point. But then, right there in the moderate 00:13:09.250 --> 00:13:12.309 adverse reactions chart, it lists respiratory 00:13:12.309 --> 00:13:16.129 depression happening in 37 to 67 percent of cases. 00:13:16.860 --> 00:13:19.820 How do we reconcile limited effects on respiratory 00:13:19.820 --> 00:13:23.559 drive with up to 67 % of patients having respiratory 00:13:23.559 --> 00:13:25.679 depression? It's a really great catch, and it's 00:13:25.679 --> 00:13:28.259 all about clinical context and the definitions 00:13:28.259 --> 00:13:31.039 of respiratory failure. When we say it has limited 00:13:31.039 --> 00:13:33.480 effects on respiratory central drive, we are 00:13:33.480 --> 00:13:36.059 comparing it directly to drugs like fentanyl 00:13:36.059 --> 00:13:38.559 or propofol. Which will reliably cause apnea. 00:13:38.820 --> 00:13:40.940 Right. They will shut off the brain stem's pacemaker, 00:13:41.500 --> 00:13:43.159 stopping the patient from breathing entirely 00:13:43.159 --> 00:13:46.279 if pushed far enough. Dexmedetomidine preserves 00:13:46.279 --> 00:13:48.600 that. brain stem drive. The brain keeps sending 00:13:48.600 --> 00:13:50.519 the signal to breathe. So if the brain is still 00:13:50.519 --> 00:13:52.740 sending the signal, why are they depressed? Because 00:13:52.740 --> 00:13:55.860 these are critically ill patients. They are profoundly 00:13:55.860 --> 00:13:58.440 relaxed by the medication. They often have existing 00:13:58.440 --> 00:14:01.879 lung pathology like pneumonia or ARDS, and their 00:14:01.879 --> 00:14:04.539 upper airway muscles can become so relaxed that 00:14:04.539 --> 00:14:07.159 the tongue falls back and obstructs the airway. 00:14:07.399 --> 00:14:09.799 Ah, so the breathing mechanics fail, even if 00:14:09.799 --> 00:14:12.970 the brain is still trying. Exactly. While the 00:14:12.970 --> 00:14:14.629 drug isn't shutting off the brain's breathing 00:14:14.629 --> 00:14:17.509 center, nurses and providers must still vigilantly 00:14:17.509 --> 00:14:20.350 monitor for respiratory depression, hypoventilation, 00:14:20.629 --> 00:14:23.370 and hypoxia. You can never just drop your guard 00:14:23.370 --> 00:14:25.570 just because a drug is marketed as safer for 00:14:25.570 --> 00:14:28.029 the respiratory system. That makes perfect sense. 00:14:28.149 --> 00:14:30.789 The signal is there, but the anatomical pathway 00:14:30.789 --> 00:14:34.070 is compromised. So given these hemodynamic and 00:14:34.070 --> 00:14:36.870 respiratory risks, when do we definitively hold 00:14:36.870 --> 00:14:39.389 this drug? Because of the profound hemodynamic 00:14:39.389 --> 00:14:42.090 risks we just covered, you hold additional doses. 00:14:42.330 --> 00:14:44.730 And this is especially true for that sublingual 00:14:44.730 --> 00:14:47.710 psychiatric formulation. If the systolic blood 00:14:47.710 --> 00:14:50.409 pressure is less than 90, the diastolic is less 00:14:50.409 --> 00:14:53.230 than 60, or the heart rate is less than 60 beats 00:14:53.230 --> 00:14:56.110 per minute. What about orthostatic changes? Yes. 00:14:56.389 --> 00:14:58.850 You also hold it if the patient is experiencing 00:14:58.850 --> 00:15:02.429 significant orthostatic postural drops. If they 00:15:02.429 --> 00:15:04.950 stand up and their pressure absolutely tanks, 00:15:05.350 --> 00:15:07.330 you do not give them more of a sympathetic drug. 00:15:07.580 --> 00:15:10.480 All right, let's translate all of this into strict 00:15:10.480 --> 00:15:13.539 medication administration protocols. Based on 00:15:13.539 --> 00:15:15.419 what we just discussed about the physiological 00:15:15.419 --> 00:15:18.360 paradox of peripheral constriction, rule number 00:15:18.360 --> 00:15:22.139 one and a massive NCLEX or ATI test point you'll 00:15:22.139 --> 00:15:26.000 see is never 5E push. Never. It must be infused. 00:15:26.100 --> 00:15:28.639 But what about the loading dose? The formal guidelines 00:15:28.639 --> 00:15:30.840 say to infuse a loading dose over 10 minutes 00:15:30.840 --> 00:15:32.759 to get them up to a steady state. And here's 00:15:32.759 --> 00:15:36.279 a massive real -world clinical pearl. in actual 00:15:36.279 --> 00:15:38.940 day -to -day clinical practice. Those loading 00:15:38.940 --> 00:15:41.460 doses are frequently completely bypassed. Wait, 00:15:41.559 --> 00:15:44.120 really? Yeah. The source text explicitly states 00:15:44.120 --> 00:15:47.440 this for adults, children, and neonates. Providers 00:15:47.440 --> 00:15:49.919 often skip the loading dose entirely and just 00:15:49.919 --> 00:15:51.820 start the continuous maintenance drip. I guess 00:15:51.820 --> 00:15:53.820 because even over 10 minutes, flooding the system 00:15:53.820 --> 00:15:55.720 with that much drug right out of the gate still 00:15:55.720 --> 00:15:58.159 carries too high a risk of inducing that severe 00:15:58.159 --> 00:16:00.179 bradycardia and hypotension we mapped out earlier. 00:16:00.600 --> 00:16:03.960 Precisely. It is infinitely safer to just start 00:16:03.960 --> 00:16:07.279 the drip and slowly, patiently titrate it up 00:16:07.279 --> 00:16:09.840 to your target sedation level rather than whisk 00:16:09.840 --> 00:16:12.340 a hemodynamic crash from a loading dose just 00:16:12.340 --> 00:16:14.679 to get them asleep. A few minutes faster. As 00:16:14.679 --> 00:16:18.059 for the actual IV logistics, the standard ASHP 00:16:18.059 --> 00:16:20.700 concentration you'll encounter is four micrograms 00:16:20.700 --> 00:16:24.100 per milliliter, usually mixed with 0 .9 % normal 00:16:24.100 --> 00:16:26.399 saline. Right. And it is very chemically stable. 00:16:26.500 --> 00:16:28.480 Yeah, good for 48 hours at room temperature. 00:16:29.000 --> 00:16:31.019 But drug interactions are critical here. And 00:16:31.019 --> 00:16:32.659 I don't just mean receptor interactions in the 00:16:32.659 --> 00:16:35.440 body. I mean physical IV line compatibility. 00:16:35.639 --> 00:16:38.519 Oh, this is so important. You cannot co -administer 00:16:38.519 --> 00:16:41.539 dexmedetomidine through the same IV line as blood, 00:16:41.740 --> 00:16:44.159 serum, or plasma. The physical compatibility 00:16:44.159 --> 00:16:46.980 simply has not been established, meaning we don't 00:16:46.980 --> 00:16:49.539 know if it will precipitate, crystallize, or 00:16:49.539 --> 00:16:52.139 degrade in the line. And regarding metabolic 00:16:52.139 --> 00:16:54.379 interactions, it actually has very minimal cytochrome 00:16:54.379 --> 00:16:58.539 P450 interactions, mainly just CYP2A6. So it 00:16:58.539 --> 00:17:00.399 plays relatively nicely with other medications 00:17:00.399 --> 00:17:02.279 in terms of liver metabolism. It's not going 00:17:02.279 --> 00:17:04.720 to aggressively block other drugs from breaking 00:17:04.720 --> 00:17:07.559 down. Let's talk about the sublingual and buccal 00:17:07.559 --> 00:17:10.059 formulation of Golmi, because the administration 00:17:10.059 --> 00:17:13.440 rules for this film are highly specific. If you 00:17:13.440 --> 00:17:16.559 are using this for acute psych agitation, you 00:17:16.559 --> 00:17:18.900 must keep it in the foil package until the exact 00:17:18.900 --> 00:17:21.940 moment of use. And if you have to cut it to give 00:17:21.940 --> 00:17:25.480 a partial dose, you must use clean, absolutely 00:17:25.480 --> 00:17:28.079 dry hands and dry scissors. Because it's a film, 00:17:28.220 --> 00:17:30.539 right? Any moisture will ruin it. Because it 00:17:30.539 --> 00:17:33.000 is a highly calibrated mucosal delivery system. 00:17:33.599 --> 00:17:36.759 Any moisture Even a drop of sweat on your glove 00:17:36.759 --> 00:17:39.059 will begin dissolving the film and ruin the dose 00:17:39.059 --> 00:17:40.920 before it even gets to the patient. Exactly. 00:17:41.039 --> 00:17:43.380 You place it under the tongue or inside the lower 00:17:43.380 --> 00:17:46.680 lip. The absolute priority for client education 00:17:46.680 --> 00:17:49.240 here, they cannot chew or swallow it. It has 00:17:49.240 --> 00:17:51.180 to dissolve into the mucosa. And they cannot 00:17:51.180 --> 00:17:53.359 have food or drink for at least 15 minutes if 00:17:53.359 --> 00:17:55.839 it's sublingual, or a full hour if it's buckle. 00:17:56.640 --> 00:17:58.660 Tying back to everything we discussed about sympathetic 00:17:58.660 --> 00:18:00.759 tone and blood pressure dropping, the patient 00:18:00.759 --> 00:18:03.640 must remain seated or lying down after administration, 00:18:03.900 --> 00:18:06.819 right? Right. The orthostatic hypotension risk 00:18:06.819 --> 00:18:09.779 is very real, and they can easily faint if they 00:18:09.779 --> 00:18:13.009 jump up. and obviously no driving or operating 00:18:13.009 --> 00:18:14.910 hazardous machinery for at least eight hours. 00:18:15.250 --> 00:18:17.470 Okay, what about organ impairment? If I have 00:18:17.470 --> 00:18:20.150 a patient with liver failure or kidney failure, 00:18:20.230 --> 00:18:22.869 do I need to adjust these doses? This is a vital 00:18:22.869 --> 00:18:25.009 distinction to make. You absolutely must consider 00:18:25.009 --> 00:18:28.170 dosage reductions for hepatic impairment liver 00:18:28.170 --> 00:18:30.309 dysfunction. Because the liver metabolizes it. 00:18:30.450 --> 00:18:33.450 Yes. The drug undergoes extensive biotransformation 00:18:33.450 --> 00:18:37.309 in the liver, specifically a process called glucuronidation. 00:18:37.799 --> 00:18:40.740 Think of glucuronidation as the liver slapping 00:18:40.740 --> 00:18:43.140 a molecular barcode on the drug so the body knows 00:18:43.140 --> 00:18:45.259 it's time to pee it out. OK, I like that barcode 00:18:45.259 --> 00:18:48.099 analogy. If the liver is failing, say, a patient 00:18:48.099 --> 00:18:51.539 has cirrhosis with a high child pew score, that 00:18:51.539 --> 00:18:54.619 barcode system is broken. The drug isn't processed, 00:18:55.059 --> 00:18:57.220 so it just circulates and builds up to toxic, 00:18:57.420 --> 00:18:59.839 heart -stopping levels. That's why you must drastically 00:18:59.839 --> 00:19:02.160 reduce the dose or titrate very carefully. OK, 00:19:02.220 --> 00:19:04.279 so the liver is the main filter. What about the 00:19:04.279 --> 00:19:07.779 kidneys? Interestingly, no specific dosage adjustments 00:19:07.779 --> 00:19:10.940 are required for real impairment. Really? None? 00:19:11.319 --> 00:19:14.470 None. Even though the metabolites exit the body 00:19:14.470 --> 00:19:16.869 through the urine, the active drug has already 00:19:16.869 --> 00:19:18.789 been dealt with and neutralized by the liver. 00:19:19.450 --> 00:19:22.210 So bad kidneys don't change your initial dosing 00:19:22.210 --> 00:19:24.690 strategy for the active drug. Liver matters. 00:19:24.890 --> 00:19:27.029 Kidneys don't for dosing adjustments, at least. 00:19:27.410 --> 00:19:29.309 To see how this actually plays out in the wild, 00:19:29.529 --> 00:19:31.930 let's look at two brief clinical scenarios. Let's 00:19:31.930 --> 00:19:35.299 do it. Imagine you are in the ICU. You have a 00:19:35.299 --> 00:19:37.519 mechanically ventilated patient who is recovering 00:19:37.519 --> 00:19:40.940 from major non -cardiac surgery. The critical 00:19:40.940 --> 00:19:44.200 care provider orders a dexmedetomidine continuous 00:19:44.200 --> 00:19:47.259 IV drip and specifically writes in the order, 00:19:47.819 --> 00:19:50.640 no loading dose. Why is this the exact right 00:19:50.640 --> 00:19:52.960 call? It's the right call because the bedside 00:19:52.960 --> 00:19:54.900 nurse needs to wake this patient up every two 00:19:54.900 --> 00:19:57.480 hours to perform accurate neurological assessments. 00:19:57.980 --> 00:20:00.220 They need that specific arousal sedation. Right. 00:20:00.539 --> 00:20:02.519 Furthermore, as they prepare to extubate the 00:20:02.519 --> 00:20:04.299 patient to pull the breathing tube out, they 00:20:04.299 --> 00:20:06.200 need the patient to maintain their own central 00:20:06.200 --> 00:20:08.960 respiratory drive. Yeah. And the provider bypass 00:20:08.960 --> 00:20:11.000 the loading dose entirely to protect the patient 00:20:11.000 --> 00:20:12.740 from a sudden blood pressure and heart rate crash. 00:20:13.099 --> 00:20:15.640 It checks every single box perfectly. It's exactly 00:20:15.640 --> 00:20:18.319 what the drug was built for. Okay, scenario two, 00:20:18.880 --> 00:20:21.450 psychiatric emergency. An adult patient with 00:20:21.450 --> 00:20:23.670 a known history of bipolar eye disorder arrives 00:20:23.670 --> 00:20:26.029 in the emergency department experiencing severe 00:20:26.029 --> 00:20:30.650 acute agitation. The provider orders 180 micrograms 00:20:30.650 --> 00:20:33.440 of the agami sublingual film. Also an excellent 00:20:33.440 --> 00:20:35.599 application. They're utilizing the centrally 00:20:35.599 --> 00:20:38.599 acting sympathetic properties to rapidly calm 00:20:38.599 --> 00:20:40.859 the nervous system and achieve a reduction in 00:20:40.859 --> 00:20:43.480 agitation. And no needles involved. Exactly. 00:20:43.660 --> 00:20:45.819 Without needing to force an IV into a highly 00:20:45.819 --> 00:20:48.680 agitated patient and without using a heavy anti 00:20:48.680 --> 00:20:51.079 -psychotic that might cause profound respiratory 00:20:51.079 --> 00:20:53.900 depression or severe extra -pyramidal side effects. 00:20:54.180 --> 00:20:56.700 And for both of those scenarios, our evaluation 00:20:56.700 --> 00:20:58.859 of effectiveness is exactly the same, right? 00:20:59.019 --> 00:21:01.180 We know the medication is working when we achieve 00:21:01.180 --> 00:21:03.549 the target level of arousal sedation in the ICU, 00:21:03.990 --> 00:21:06.630 or a measurable reduction in that acute agitation 00:21:06.630 --> 00:21:09.710 in the ED, all while maintaining stable hemodynamics. 00:21:10.029 --> 00:21:11.890 Meaning, their heart rate and blood pressure 00:21:11.890 --> 00:21:14.750 haven't crashed. Hemodynamic stability is the 00:21:14.750 --> 00:21:16.670 tightrope you walk with this drug from start 00:21:16.670 --> 00:21:19.390 to finish. Which brings us to the final 80 -20 00:21:19.390 --> 00:21:22.109 review. I want to give you a memory hook right 00:21:22.109 --> 00:21:24.250 out of the gate to lock this physiology into 00:21:24.250 --> 00:21:26.569 your brain. Always helpful to have a hook. When 00:21:26.569 --> 00:21:29.369 you think of this drug, remember, pre -STEC -X 00:21:29.559 --> 00:21:32.160 keeps you de -extrous enough to wake up, but 00:21:32.160 --> 00:21:34.539 slows your heart to a crawl. Okay, I like it. 00:21:34.720 --> 00:21:39.160 Or, if you prefer a simpler acronym, DAX equals 00:21:39.160 --> 00:21:42.460 decreases excitement excellently. Decreases excitement 00:21:42.460 --> 00:21:45.539 excellently. That covers both the ICU sedation 00:21:45.539 --> 00:21:48.309 and the psychiatric agitation. perfectly. So 00:21:48.309 --> 00:21:49.710 what does this all mean? Let's bring it home 00:21:49.710 --> 00:21:53.150 with the absolute essentials, the 20 % you absolutely 00:21:53.150 --> 00:21:55.990 must know to master this drug for clinical practice 00:21:55.990 --> 00:21:58.210 and your exams. I'll take the first one. Number 00:21:58.210 --> 00:22:01.130 one, it is a highly specific alpha -2 agonist. 00:22:01.789 --> 00:22:04.690 Remember, 1600 to 1 specificity, making it eight 00:22:04.690 --> 00:22:07.089 times more specific than clonidine. Number two, 00:22:07.109 --> 00:22:09.390 it offers a rousable sedation without shutting 00:22:09.390 --> 00:22:11.589 off the brain stem's respiratory drive. That 00:22:11.589 --> 00:22:14.329 is its superpower. Number three, because it blocks 00:22:14.329 --> 00:22:16.710 the sympathetic nervous system, the major safety 00:22:16.680 --> 00:22:19.480 concerns are severe bradycardia and hypotension. 00:22:19.700 --> 00:22:22.119 Number four, because of those safety concerns, 00:22:22.359 --> 00:22:24.880 your priority intervention is never rapid 4V 00:22:24.880 --> 00:22:28.380 push because that paradoxically causes dangerous 00:22:28.380 --> 00:22:31.440 transient hypertension followed by severe reflex 00:22:31.440 --> 00:22:34.279 bradycardia as the body panics. And similarly, 00:22:34.660 --> 00:22:37.059 IV loading doses are frequently bypassed entirely. 00:22:37.359 --> 00:22:41.460 Number five, the sublingual or buccal film, Igalmi, 00:22:41.740 --> 00:22:44.299 is a game changer for acute schizophrenia or 00:22:44.299 --> 00:22:48.380 bipolar agitation. Just remember the strict mucosal 00:22:48.380 --> 00:22:51.380 administration rules, dry hands, don't chew or 00:22:51.380 --> 00:22:53.960 swallow, and wait 15 minutes to an hour to eat 00:22:53.960 --> 00:22:56.819 or drink. And number six, it requires hepatic 00:22:56.819 --> 00:22:59.019 dose adjustments for liver impairment because 00:22:59.019 --> 00:23:01.359 the liver processes it, but no renal adjustments 00:23:01.359 --> 00:23:04.049 are needed. And finally, never physically mix 00:23:04.049 --> 00:23:07.150 the IV form with blood products. Those six facts 00:23:07.150 --> 00:23:09.869 are your ultimate survival guide for dexmedetomidine. 00:23:10.170 --> 00:23:11.829 But before we wrap, I want to leave you with 00:23:11.829 --> 00:23:14.349 a final thought to mull over. Yeah, if we connect 00:23:14.349 --> 00:23:15.990 this to the bigger picture of where medicine 00:23:15.990 --> 00:23:18.769 is heading, we now have a highly selective alpha 00:23:18.769 --> 00:23:21.829 -2 agonist that can achieve targeted, arousable 00:23:21.829 --> 00:23:25.329 sedation via a simple sublingual film, all without 00:23:25.329 --> 00:23:27.390 shutting down the brain's fundamental respiratory 00:23:27.390 --> 00:23:30.200 drive. Which is huge. It is. So the question 00:23:30.200 --> 00:23:33.200 becomes, how might this level of highly selective 00:23:33.200 --> 00:23:36.259 neurological targeting revolutionize the future 00:23:36.259 --> 00:23:39.140 of outpatient anxiety and panic treatments? Are 00:23:39.140 --> 00:23:41.859 we looking at a future where these powerful tools 00:23:41.859 --> 00:23:44.660 move completely out of the intensive care unit 00:23:44.660 --> 00:23:47.819 and into our daily lives? Right. Allowing people 00:23:47.819 --> 00:23:51.039 to safely manage extreme stress or panic attacks 00:23:51.039 --> 00:23:53.640 at home without losing their ability to function. 00:23:53.799 --> 00:23:56.220 It really makes you rethink what sedation even 00:23:56.220 --> 00:23:59.539 means. We started this deep talking about a light 00:23:59.539 --> 00:24:02.500 switch versus a dimmer. Dexminitamidine proved 00:24:02.500 --> 00:24:04.240 that we don't have to plunge our patients into 00:24:04.240 --> 00:24:06.740 total darkness to keep them calm. Sometimes we 00:24:06.740 --> 00:24:08.920 just need to quietly turn down the noise. Thank 00:24:08.920 --> 00:24:11.200 you for joining us on this deep dive. Keep questioning 00:24:11.200 --> 00:24:13.619 the physiology, keep applying that 80 -20 rule, 00:24:13.819 --> 00:24:14.740 and we'll see you next time.