WEBVTT 00:00:00.720 --> 00:00:03.839 Hey guys, this right here is going to be PALS, 00:00:03.940 --> 00:00:07.919 the Pediatric Advanced Life Support. And the 00:00:07.919 --> 00:00:09.640 way it's going to go is I'm going to try to keep 00:00:09.640 --> 00:00:13.380 it in this order. The systematic approach to 00:00:13.380 --> 00:00:17.699 the pediatric patients, pediatric shock recognition, 00:00:18.100 --> 00:00:23.199 pediatric management of shock, recognizing respiratory 00:00:23.199 --> 00:00:27.850 distress, managing respiratory distress. recognizing 00:00:27.850 --> 00:00:30.710 cardiac arrest, management of cardiac arrest, 00:00:31.109 --> 00:00:34.170 arrhythmias, recognition of those arrhythmias, 00:00:34.350 --> 00:00:37.670 and then management of those arrhythmias. I don't 00:00:37.670 --> 00:00:41.049 remember PALS being this deep, but again, it's 00:00:41.049 --> 00:00:43.829 been almost two years since I've taken PALS, 00:00:44.070 --> 00:00:47.689 but it seems like it's a lot more in depth than 00:00:47.689 --> 00:00:52.710 just your normal ACLS. So this material is coming 00:00:52.710 --> 00:00:56.840 straight from the book. For the course just make 00:00:56.840 --> 00:00:59.880 sure that you guys are reading that material 00:00:59.880 --> 00:01:06.680 Because I did not add some stuff in there like 00:01:06.680 --> 00:01:10.500 team dynamics or resources for respiratory care 00:01:10.500 --> 00:01:15.459 or Management of the post cardiac arrest, you 00:01:15.459 --> 00:01:17.760 know stuff like that. I didn't include that into 00:01:17.760 --> 00:01:22.260 this stuff So if you guys need that or want that, 00:01:22.299 --> 00:01:25.420 then by all means, read the book or, you know, 00:01:25.519 --> 00:01:29.359 Google it or whatever. But this right here is 00:01:29.359 --> 00:01:32.879 going to be the intro for the pals stuff. So 00:01:32.879 --> 00:01:35.439 I hope you guys enjoy the pediatric advanced 00:01:35.439 --> 00:01:50.120 life support material for the course. This is 00:01:50.120 --> 00:01:53.680 all going to happen super fast. Welcome to the 00:01:53.680 --> 00:02:27.669 emergency room. Welcome back to the deep dive. 00:02:28.289 --> 00:02:30.990 If you're an ER nurse or really any critical 00:02:30.990 --> 00:02:32.590 care professional getting ready for your Pell 00:02:32.590 --> 00:02:37.150 S certification, then today's deep dive is absolutely 00:02:37.150 --> 00:02:39.909 for you. Yeah, this is essential stuff. We are 00:02:39.909 --> 00:02:43.490 jumping headfirst into, I think, the most foundational 00:02:43.490 --> 00:02:46.550 piece of pediatric advanced life support, arrhythmia 00:02:46.550 --> 00:02:49.360 recognition. It really is. I mean, this is the 00:02:49.360 --> 00:02:52.080 single most crucial skill you can master. The 00:02:52.080 --> 00:02:54.939 PAL -S algorithms are, frankly, they're worthless 00:02:54.939 --> 00:02:57.560 if you can't accurately see the rhythm on the 00:02:57.560 --> 00:02:59.780 monitor and then connect that to the kid in the 00:02:59.780 --> 00:03:01.860 bed. Right, to the physiological instability. 00:03:02.000 --> 00:03:05.599 Exactly. So our mission today isn't just to review 00:03:05.599 --> 00:03:07.939 definitions from a textbook. We want to get into 00:03:07.939 --> 00:03:11.120 the clinical reasoning, the why behind unstable 00:03:11.120 --> 00:03:13.919 bradycardia and these really rapid tachycardias. 00:03:13.979 --> 00:03:16.219 So you can actually anticipate the next steps 00:03:16.219 --> 00:03:18.430 in the algorithm. before anyone even has to call 00:03:18.430 --> 00:03:20.409 them out. That's the goal. That's when you know 00:03:20.409 --> 00:03:22.610 you've mastered it. We've distilled a whole stack 00:03:22.610 --> 00:03:25.330 of foundational PLS sources and they all drill 00:03:25.330 --> 00:03:27.750 down into the path of physiology of these rhythms, 00:03:28.150 --> 00:03:30.909 giving you those, those nuanced characteristics 00:03:30.909 --> 00:03:32.650 you need to tell the difference. The difference 00:03:32.650 --> 00:03:35.069 between a stable child who's just in distress 00:03:35.069 --> 00:03:37.949 and a child who is, you know, right on the brink 00:03:37.949 --> 00:03:40.250 of cardiopulmonary arrest. This is basically 00:03:40.250 --> 00:03:42.889 your shortcut to mastering that rhythm recognition 00:03:42.889 --> 00:03:45.580 piece of the certification. And the material 00:03:45.580 --> 00:03:48.500 we're drawing from, it specifically focuses on 00:03:48.500 --> 00:03:52.080 recognizing compromise, understanding those key 00:03:52.080 --> 00:03:54.639 ECG differentiators, especially, and this is 00:03:54.639 --> 00:03:57.699 the big one, between sinus tach and SVT, and 00:03:57.699 --> 00:04:00.180 then, of course, classifying how severe a bradycardia 00:04:00.180 --> 00:04:02.479 is. Mastering this is step one, the critical 00:04:02.479 --> 00:04:04.340 first step. Absolutely. OK, let's unpack this. 00:04:04.360 --> 00:04:06.099 And I want to start right at the physiological 00:04:06.099 --> 00:04:09.800 core. Why is a child's heart rate so uniquely 00:04:09.800 --> 00:04:12.879 vulnerable? And why does a pediatric arrest look 00:04:12.879 --> 00:04:15.180 so, so different from what we usually see in 00:04:15.180 --> 00:04:17.720 adults? That is the perfect place to start. And 00:04:17.720 --> 00:04:20.560 it all begins with a really simple equation for 00:04:20.560 --> 00:04:23.360 how we maintain hemodynamic stability. It's cardiac 00:04:23.360 --> 00:04:25.220 output. Cardiac output. Which is just the volume 00:04:25.220 --> 00:04:27.490 of blood the heart pumps out per minute. And 00:04:27.490 --> 00:04:29.410 you calculate it by taking stroke volume and 00:04:29.410 --> 00:04:31.370 multiplying it by heart rate. And this simple 00:04:31.370 --> 00:04:33.550 equation, this is where kids' physiology just 00:04:33.550 --> 00:04:36.110 takes a sharp turn away from an adult's. It really 00:04:36.110 --> 00:04:38.709 does. Because as practitioners, you know, we're 00:04:38.709 --> 00:04:41.009 often dealing with adult codes. And we know if 00:04:41.009 --> 00:04:43.910 an adult's heart rate dips a little bit, the 00:04:43.910 --> 00:04:46.170 heart have this amazing ability to compensate. 00:04:46.350 --> 00:04:48.829 It can just increase its stroke volume. Yeah, 00:04:48.829 --> 00:04:51.290 it just pumps harder. It pumps more blood with 00:04:51.290 --> 00:04:53.670 each contraction to keep that cardiac output 00:04:53.670 --> 00:04:56.480 stable. But that flexibility... Yeah. It just 00:04:56.480 --> 00:04:58.660 doesn't exist in infants and young children. 00:04:58.800 --> 00:05:00.420 Not at all. And the sources are really clear 00:05:00.420 --> 00:05:02.939 on this. The young heart muscle, especially the 00:05:02.939 --> 00:05:06.779 ventricles, it's just less compliant. It can't 00:05:06.779 --> 00:05:09.240 stretch or contract with that same kind of force 00:05:09.240 --> 00:05:11.959 variability that an adult heart has. So to put 00:05:11.959 --> 00:05:14.040 it simply, the stroke volume, the amount of blood 00:05:14.040 --> 00:05:16.560 they can eject with each beat is pretty much 00:05:16.560 --> 00:05:19.000 fixed. It's relatively fixed, yeah. Especially 00:05:19.000 --> 00:05:21.120 when they're in a volume sensitive state, like 00:05:21.120 --> 00:05:23.800 dehydration or shock. OK, so if stroke volume 00:05:23.800 --> 00:05:27.110 is off the table, The body really only has one 00:05:27.110 --> 00:05:30.449 major tool left in the toolbox to control cardiac 00:05:30.449 --> 00:05:33.089 output and meet the body's demands. Exactly, 00:05:33.430 --> 00:05:36.129 heart rate. It becomes the primary, essential, 00:05:36.529 --> 00:05:38.889 and frankly, often the only determinant of cardiac 00:05:38.889 --> 00:05:41.970 output in infants and young children. Which means 00:05:41.970 --> 00:05:45.290 any deviation from that normal age -appropriate 00:05:45.290 --> 00:05:48.589 heart rate range, whether it's too slow, bradycardia, 00:05:48.610 --> 00:05:51.980 or too fast, tachycardia, it's going to rapidly 00:05:51.980 --> 00:05:54.839 result in a critically low cardiac output. That 00:05:54.839 --> 00:05:57.899 one physiological constraint, it just underscores 00:05:57.899 --> 00:06:00.720 why rate control is the intervention that buys 00:06:00.720 --> 00:06:03.160 you the most time in a pediatric resuscitation. 00:06:03.399 --> 00:06:06.120 It is. If you can fix the rate, you often fix 00:06:06.120 --> 00:06:08.819 the output. It's that simple and that critical. 00:06:09.040 --> 00:06:11.399 And that distinction, that total dependence on 00:06:11.399 --> 00:06:14.970 heart rate, it immediately tells us why a profound 00:06:14.970 --> 00:06:18.189 bradycardia in an infant is so much more catastrophic, 00:06:18.209 --> 00:06:20.009 so much faster than it would be in an adult. 00:06:20.490 --> 00:06:22.689 Absolutely. And that catastrophic drop in output, 00:06:22.709 --> 00:06:24.930 that leads us right to our next critical concept, 00:06:25.009 --> 00:06:27.230 which is defining cardiopulmonary compromise. 00:06:27.470 --> 00:06:29.410 Right. Because an abnormal rhythm is one thing. 00:06:29.430 --> 00:06:31.629 It's a flag. At the compromise. Compromise is 00:06:31.629 --> 00:06:34.149 the siren. It's the thing screaming for you to 00:06:34.149 --> 00:06:36.470 intervene right now. And your ability to spot 00:06:36.470 --> 00:06:38.410 that compromise, that's what dictates whether 00:06:38.410 --> 00:06:40.810 you have 10 minutes to figure things out or 10 00:06:40.810 --> 00:06:43.529 seconds to act. So how do the PLS guidelines 00:06:43.529 --> 00:06:46.689 based on these sources? How do they define that 00:06:46.689 --> 00:06:49.430 critical state where poor output is actually 00:06:49.430 --> 00:06:51.810 leading to organ failure? It's defined by the 00:06:51.810 --> 00:06:54.589 presence of three major criteria, which are really, 00:06:54.589 --> 00:06:56.370 I mean, they're the clinical signs of shock. 00:06:56.730 --> 00:06:58.889 First, you're looking for hypotension. So a blood 00:06:58.889 --> 00:07:00.750 pressure that's below the normal threshold for 00:07:00.750 --> 00:07:04.189 that child's age. Correct. Second, acutely altered 00:07:04.189 --> 00:07:06.550 mental status. This could be a decreased level 00:07:06.550 --> 00:07:09.329 of consciousness, lethargy, or in an infant, 00:07:09.889 --> 00:07:13.329 that severe persistent irritability. OK. And 00:07:13.329 --> 00:07:15.170 the third? And third, you're looking for... for 00:07:15.170 --> 00:07:17.750 definitive signs of shock, so clear evidence 00:07:17.750 --> 00:07:20.730 of poor end -organ perfusion. Let's focus on 00:07:20.730 --> 00:07:22.769 those signs of shock for a second, because for 00:07:22.769 --> 00:07:24.949 an ER nurse, these are often the first things 00:07:24.949 --> 00:07:26.689 you can put your hands on. They tell the story 00:07:26.689 --> 00:07:28.930 before the monitor even spits out the full rhythm. 00:07:29.189 --> 00:07:31.670 You're absolutely right. Poor end -organ perfusion, 00:07:31.670 --> 00:07:34.069 it shows up as a whole cascade of clinical signs. 00:07:34.269 --> 00:07:37.620 You're looking for... cool clammy extremities, 00:07:37.680 --> 00:07:40.160 you're checking for a delayed cap refill time. 00:07:40.240 --> 00:07:42.420 One in three seconds. Greater than three seconds, 00:07:42.519 --> 00:07:46.420 yeah. You're feeling for weak or thready peripheral 00:07:46.420 --> 00:07:49.819 pulses compared to their central pulses, like 00:07:49.819 --> 00:07:51.959 the femoral. You're looking for modeling of the 00:07:51.959 --> 00:07:54.319 skin, diaphoresis. Which are that excessive sweating 00:07:54.319 --> 00:07:56.699 you see when their sympathetic tone is just cranked 00:07:56.699 --> 00:07:58.860 way up. Exactly. And what about the more subtle 00:07:58.860 --> 00:08:01.420 behavioral signs, especially in kids who can't 00:08:01.420 --> 00:08:04.089 talk to you? That's where it gets really tricky, 00:08:04.110 --> 00:08:07.350 and it takes experience. In an infant, compromise 00:08:07.350 --> 00:08:10.829 might just look like profound irritability, or 00:08:10.829 --> 00:08:13.870 they're not feeding well, or they're just unusually 00:08:13.870 --> 00:08:16.829 sleepy. In older kids, you might hear them complain 00:08:16.829 --> 00:08:19.350 about a vague feeling of discomfort or chest 00:08:19.350 --> 00:08:22.709 pain, dizziness, or you might just see a sudden 00:08:22.709 --> 00:08:25.589 change in how they're breathing, leading to respiratory 00:08:25.589 --> 00:08:27.529 distress. So if you see any of those clinical 00:08:27.529 --> 00:08:30.149 signs... and you pair them with an abnormal heart 00:08:30.149 --> 00:08:32.009 rate on the monitor. You are dealing with an 00:08:32.009 --> 00:08:34.370 unstable arrhythmia and you have to move straight 00:08:34.370 --> 00:08:36.629 to intervention. You have to assess the rhythm 00:08:36.629 --> 00:08:39.730 and the perfusion together, always. So the real 00:08:39.730 --> 00:08:42.450 challenge for the nurse is to recognize that 00:08:42.450 --> 00:08:45.590 that early irritability or that decreased responsiveness 00:08:45.590 --> 00:08:48.370 physiologically, that's shock until you prove 00:08:48.370 --> 00:08:50.919 it's not. You can't separate the rhythm strip 00:08:50.919 --> 00:08:52.860 from the child in the bed. You can't. They're 00:08:52.860 --> 00:08:54.799 two parts of the same story. Okay, let's shift 00:08:54.799 --> 00:08:58.360 our focus now to the slow rates. Let's dig into 00:08:58.360 --> 00:09:02.820 bradycardia. What exactly constitutes bradycardia 00:09:02.820 --> 00:09:06.019 in the PALS world? Well, the simple definition 00:09:06.019 --> 00:09:09.379 is a heart rate that's slow relative to the child's. 00:09:09.419 --> 00:09:12.320 age, their level of activity, and this is the 00:09:12.320 --> 00:09:14.919 key part, their clinical condition. But the rhythm 00:09:14.919 --> 00:09:17.299 that really demands our immediate attention is 00:09:17.299 --> 00:09:19.899 systematic bradycardia. That's the one. Let's 00:09:19.899 --> 00:09:21.879 be really precise about that definition. Please. 00:09:21.940 --> 00:09:23.779 It's a heart rate that is slower than the normal 00:09:23.779 --> 00:09:25.759 range for that child's age, and usually we're 00:09:25.759 --> 00:09:27.779 talking about a rate that is persistently less 00:09:27.779 --> 00:09:30.779 than 60 beats per minute that is also accompanied 00:09:30.779 --> 00:09:33.000 by those signs of cardiopulmonary compromise 00:09:33.000 --> 00:09:35.340 we just talked about. And the prognosis for this 00:09:35.340 --> 00:09:38.940 rhythm, I mean... It's grim if you turn it around 00:09:38.940 --> 00:09:41.620 immediately. It's classified as an ominous sign 00:09:41.620 --> 00:09:44.059 of impending cardiac arrest. I mean, if that 00:09:44.059 --> 00:09:46.779 heart rate drops below 60 and you've got poor 00:09:46.779 --> 00:09:49.779 perfusion and that slow rate is sticking around 00:09:49.779 --> 00:09:52.059 despite you giving them good oxygenation and 00:09:52.059 --> 00:09:54.200 inhalation... Then the guidelines say you start 00:09:54.200 --> 00:09:57.799 CPR. You have to. You initiate chest compressions 00:09:57.799 --> 00:10:01.259 immediately. That rhythm tells you that the child's 00:10:01.259 --> 00:10:04.019 compensatory mechanisms have failed. Their cardiac 00:10:04.019 --> 00:10:06.200 output just isn't sustainable anymore. So we 00:10:06.200 --> 00:10:09.179 need to understand the why. Why does a kid's 00:10:09.179 --> 00:10:11.860 heart slow down to this critical pre -arrest 00:10:11.860 --> 00:10:15.080 level? The why is, overwhelmingly, one thing. 00:10:15.419 --> 00:10:18.809 Tissue hypoxia. Okay. Progressive hypoxemia, 00:10:19.009 --> 00:10:21.509 or respiratory failure, is the number one cause 00:10:21.509 --> 00:10:23.850 of symptomatic bradycardia in children. And this 00:10:23.850 --> 00:10:26.330 is a huge differentiator from adults, where bradycardia 00:10:26.330 --> 00:10:28.629 is often an intrinsic electrical problem. Right. 00:10:28.850 --> 00:10:31.429 Primary heart disease. In kids, the slow heart 00:10:31.429 --> 00:10:34.029 rate is usually a physiological consequence of 00:10:34.029 --> 00:10:36.230 them not being able to breathe effectively. Which 00:10:36.230 --> 00:10:38.610 means, from a management standpoint, our first 00:10:38.610 --> 00:10:41.600 move is always respiratory. As the nurse, you're 00:10:41.600 --> 00:10:44.419 not reaching for atropine first. No, you're not. 00:10:44.519 --> 00:10:46.679 You're securing the airway and you're maximizing 00:10:46.679 --> 00:10:49.860 ventilation. Exactly. Your absolute priority 00:10:49.860 --> 00:10:52.940 is to provide adequate oxygenation and ventilation. 00:10:53.340 --> 00:10:55.360 Because you're treating the underlying hypoxia 00:10:55.360 --> 00:10:57.899 that's causing that vagal response and the bradycardia, 00:10:58.179 --> 00:11:00.340 you treat the primary cause first. And if you 00:11:00.340 --> 00:11:02.860 reverse the hypoxia? The rate should climb right 00:11:02.860 --> 00:11:05.600 back to normal. If it doesn't, that's when you 00:11:05.600 --> 00:11:07.940 start suspecting a primary cardiac problem or 00:11:07.940 --> 00:11:10.500 some other profound secondary cause. Okay, so 00:11:10.500 --> 00:11:12.480 let's use the source materials classification 00:11:12.480 --> 00:11:15.399 here to guide us through how to differentiate 00:11:15.399 --> 00:11:18.529 these causes quickly. Primary versus secondary 00:11:18.529 --> 00:11:22.029 bradycardia. Because this distinction, it directs 00:11:22.029 --> 00:11:24.990 the entire plan. It does. So primary bradycardia, 00:11:25.110 --> 00:11:27.049 or intrinsic bradycardia, it originates in the 00:11:27.049 --> 00:11:29.450 heart itself. This is from a congenital or an 00:11:29.450 --> 00:11:31.769 acquired heart condition that directly damages 00:11:31.769 --> 00:11:34.509 the conduction system. The SA node, the AV node, 00:11:34.610 --> 00:11:37.429 the wiring. All of it. The problem is structural 00:11:37.429 --> 00:11:40.289 or electrical, and it's inside the cardiac system. 00:11:40.490 --> 00:11:42.629 What are some common examples of primary causes 00:11:42.629 --> 00:11:45.799 that we might see? Things like congenital abnormalities 00:11:45.799 --> 00:11:48.340 that mess with the conduction system's integrity, 00:11:49.539 --> 00:11:51.899 surgical injury after a complex cardiac repair, 00:11:52.200 --> 00:11:55.379 or diseases like a severe cardiomyopathy or myocarditis. 00:11:55.840 --> 00:11:59.559 So often, kids with a known complex medical history. 00:11:59.820 --> 00:12:03.259 Very often, yes. Now, contrast that with secondary 00:12:03.259 --> 00:12:05.360 bradycardia. This is the one we see most often 00:12:05.360 --> 00:12:08.379 in the ER. It's a reflection of a systemic illness. 00:12:08.639 --> 00:12:10.360 So it's not the heart's fault. Something else 00:12:10.360 --> 00:12:13.340 is making it slow down. Exactly. Secondary bradycardia 00:12:13.340 --> 00:12:15.940 is caused by non -cardiac conditions that alter 00:12:15.940 --> 00:12:18.460 the normal electrical conduction, usually by 00:12:18.460 --> 00:12:21.080 depressing the SA or AV node. And this is where 00:12:21.080 --> 00:12:23.299 you have to immediately map that rhythm back 00:12:23.299 --> 00:12:25.519 to your Hs and Ts. Okay, let's list them out. 00:12:25.840 --> 00:12:28.059 What are the Hs and Ts that are most relevant 00:12:28.059 --> 00:12:30.919 for a secondary bradycardia? Because this is 00:12:30.919 --> 00:12:32.860 the mental map the nurse needs to anticipate. 00:12:33.100 --> 00:12:35.539 what labs to draw and what interventions to prep. 00:12:35.659 --> 00:12:38.519 For sure. So the key secondary causes are hypoxia 00:12:38.519 --> 00:12:40.440 number one, always, it drives the rate down. 00:12:40.879 --> 00:12:43.360 Then hypothermia, which severely depresses the 00:12:43.360 --> 00:12:46.240 metabolic rate and nodal function. Hypotension, 00:12:46.299 --> 00:12:48.440 because that causes poor coronary perfusion, 00:12:48.580 --> 00:12:50.639 which just stresses the myocardium even more. 00:12:51.309 --> 00:12:54.590 Then you have hydrogen ion excess, which is acidosis, 00:12:55.169 --> 00:12:58.269 hypoglycemia, and then a big one, drugs or toxins, 00:12:58.750 --> 00:13:01.850 things like sedatives, opioids, digoxin, beta 00:13:01.850 --> 00:13:05.570 blockers, calcium channel blockers. As the nurse, 00:13:05.610 --> 00:13:08.669 if that rate is slow, you are proactively hunting 00:13:08.669 --> 00:13:11.429 for the source of one of these systemic problems. 00:13:11.710 --> 00:13:14.210 Let's move to the monitor. Beyond just the slow 00:13:14.210 --> 00:13:16.889 rate, what are the ECG characteristics that help 00:13:16.889 --> 00:13:20.299 us pinpoint what's going on? OK, so first. Obviously, 00:13:20.580 --> 00:13:22.700 their rate is low for their age. Now, P waves. 00:13:23.200 --> 00:13:25.059 They may or may not be visible. If you see them, 00:13:25.159 --> 00:13:27.139 it means the atria are firing, but they might 00:13:27.139 --> 00:13:29.659 be dissociated. meaning they don't lead to a 00:13:29.659 --> 00:13:32.259 QRS complex. Right, and the QRS complex itself 00:13:32.259 --> 00:13:34.899 gives you a clue. It can be narrow or wide. A 00:13:34.899 --> 00:13:37.399 wide QRS and a bradycardia suggest the impulse 00:13:37.399 --> 00:13:39.120 is starting way down in the ventricles, like 00:13:39.120 --> 00:13:41.379 an escape rhythm, or there's a severe block plus 00:13:41.379 --> 00:13:43.820 a pre -existing bundle branch block. Either way, 00:13:43.820 --> 00:13:46.379 it's generally more ominous. And that leads us 00:13:46.379 --> 00:13:49.379 right into the complexities of AV block classification. 00:13:49.779 --> 00:13:52.639 This is essential for the ER nurse to know, because 00:13:52.639 --> 00:13:54.620 it determines the severity of the conduction 00:13:54.620 --> 00:13:57.259 failure and how urgently you might need to start 00:13:57.259 --> 00:14:00.769 pacing. It is. AV block is just a disturbance 00:14:00.769 --> 00:14:03.529 in conduction between the atria and the ventricles. 00:14:03.929 --> 00:14:07.250 And we divide it into three degrees of essentially 00:14:07.250 --> 00:14:10.049 progressive failure. Let's start with the simplest, 00:14:10.370 --> 00:14:13.070 first degree AV block. First degree is purely 00:14:13.070 --> 00:14:15.710 an electrical delay. You have a constant but 00:14:15.710 --> 00:14:18.210 prolonged PR interval. So the signal gets through 00:14:18.210 --> 00:14:19.909 every single time. It's just a little bit slow 00:14:19.909 --> 00:14:22.289 going to the AV node. And clinically, what does 00:14:22.289 --> 00:14:24.679 that mean for the patient? Clinically, the sources 00:14:24.679 --> 00:14:27.379 all agree this is usually asymptomatic. It rarely 00:14:27.379 --> 00:14:30.200 requires treatment on its own. It's more of a 00:14:30.200 --> 00:14:32.740 finding. What's causing that delay? It's often 00:14:32.740 --> 00:14:35.600 just enhanced vagal tone, or it could be drug 00:14:35.600 --> 00:14:37.820 effects, digoxin, beta blockers. You know the 00:14:37.820 --> 00:14:40.559 list. It can also be an early sign of myocarditis. 00:14:41.059 --> 00:14:43.320 But often, if you just adjust the medication 00:14:43.320 --> 00:14:46.179 or correct some mild physiological issue, that 00:14:46.179 --> 00:14:48.620 PR interval shortens right back up. OK, so now 00:14:48.620 --> 00:14:51.759 we get to second degree mobitz type I. also known 00:14:51.759 --> 00:14:53.960 as Venkabok. This block is happening a little 00:14:53.960 --> 00:14:56.620 higher up in the AV node itself. Venkabok has 00:14:56.620 --> 00:14:59.440 that classic pattern you learned. The PR interval 00:14:59.440 --> 00:15:02.139 gets progressively longer with each beat until 00:15:02.139 --> 00:15:04.519 finally one P wave is completely blocked. It 00:15:04.519 --> 00:15:06.580 just doesn't conduct to the ventricles. And then 00:15:06.580 --> 00:15:09.639 the cycle repeats. Longer, longer, longer drop. 00:15:09.779 --> 00:15:11.980 Now you have a Venkabok. That's the one. The 00:15:11.980 --> 00:15:14.919 key is that progressive PR lengthening. And since 00:15:14.919 --> 00:15:17.559 this block is happening higher up, at the AV 00:15:17.559 --> 00:15:20.220 node level, what are the clinical implications? 00:15:20.480 --> 00:15:23.000 Is it as dangerous? It's generally less severe 00:15:23.000 --> 00:15:25.620 than a type 2 because the bundle branches, the 00:15:25.620 --> 00:15:28.480 lower wiring is usually fine. So the ventricular 00:15:28.480 --> 00:15:30.919 rate, while it's irregular, is often good enough 00:15:30.919 --> 00:15:34.220 to maintain perfusion. So the patient might feel... 00:15:34.279 --> 00:15:37.679 What? A little lightheaded? Maybe some presyncope 00:15:37.679 --> 00:15:40.940 or lightheadedness, but rarely a full hemodynamic 00:15:40.940 --> 00:15:43.580 collapse. And the causes are often transient 00:15:43.580 --> 00:15:46.600 things, like drug effects or increased parasympathetic 00:15:46.600 --> 00:15:48.659 tone. OK, now let's contrast that immediately 00:15:48.659 --> 00:15:51.899 with second -degree mobates type 2. Why is type 00:15:51.899 --> 00:15:55.029 2 so much more dangerous? Mobitz type 2 is a 00:15:55.029 --> 00:15:57.330 much more serious problem, usually because it's 00:15:57.330 --> 00:15:59.110 happening lower down in the conduction system, 00:15:59.269 --> 00:16:01.169 like in the bundle of his or the bundle branches. 00:16:01.409 --> 00:16:03.970 And here's the key distinction on the ECG. The 00:16:03.970 --> 00:16:06.470 PR interval of the beats that do conduct remains 00:16:06.470 --> 00:16:09.090 constant. It doesn't lengthen. It's just that 00:16:09.090 --> 00:16:12.710 some P waves dot poof, they fail to conduct entirely. 00:16:13.100 --> 00:16:16.519 often in a fixed ratio like a 2 .1 or a 3 .1 00:16:16.519 --> 00:16:18.720 block. And if the problem is lower down in the 00:16:18.720 --> 00:16:21.580 bundle branches, that means any subsequent block 00:16:21.580 --> 00:16:23.580 could lead straight to a complete heart block. 00:16:24.039 --> 00:16:26.559 Precisely. Because the block is distal to the 00:16:26.559 --> 00:16:29.379 AV node, any escape rhythm that has to kick in 00:16:29.379 --> 00:16:32.679 is going to be slower. less reliable, and originate 00:16:32.679 --> 00:16:35.220 lower in the ventricle. Which means a wider QRS. 00:16:35.379 --> 00:16:38.740 A wider, slower, much less stable rhythm. This 00:16:38.740 --> 00:16:42.120 makes Mobitz type 2 inherently unstable. It's 00:16:42.120 --> 00:16:44.480 much more likely to cause syncope or rapidly 00:16:44.480 --> 00:16:46.559 progress to a third -degree block. So if you 00:16:46.559 --> 00:16:48.240 see a Mobitz 2, you're thinking about pacing 00:16:48.240 --> 00:16:50.279 much sooner. Absolutely. You're getting the pads 00:16:50.279 --> 00:16:52.639 on. You're anticipating the need for external 00:16:52.639 --> 00:16:55.240 or transvenous pacing way sooner than you would 00:16:55.240 --> 00:16:57.759 for a type I. And that brings us to the rhythm 00:16:57.759 --> 00:17:00.620 that requires immediate life support, third degree 00:17:00.620 --> 00:17:04.279 or complete heart block. This is a total electrical 00:17:04.279 --> 00:17:06.539 failure between the atria and the ventricles. 00:17:06.900 --> 00:17:09.339 There is absolutely no relationship between the 00:17:09.339 --> 00:17:12.059 P waves, which is your atrial activity, and the 00:17:12.059 --> 00:17:14.559 QRS complexes, your ventricular activity. They're 00:17:14.559 --> 00:17:16.819 completely divorced. Completely. The atria are 00:17:16.819 --> 00:17:18.880 firing at their own rate and the ventricles are 00:17:18.880 --> 00:17:20.759 firing at theirs. They're totally independent. 00:17:20.940 --> 00:17:23.000 Which leaves the ventricles relying on a very 00:17:23.000 --> 00:17:26.339 slow very unreliable pacemaker. Correct. The 00:17:26.339 --> 00:17:29.359 rhythm is maintained by a very slow, often wide 00:17:29.359 --> 00:17:33.180 ventricular escape rhythm, and this loss of coordination, 00:17:33.380 --> 00:17:36.619 this AV dissociation, and the profound drop in 00:17:36.619 --> 00:17:38.900 heart rate just cripples cardiac output. Leading 00:17:38.900 --> 00:17:41.599 to severe symptoms. Severe symptoms. Fatigue, 00:17:41.740 --> 00:17:44.619 syncope, shock. The causes are things like extensive 00:17:44.619 --> 00:17:47.480 conduction system disease, toxicity, or just 00:17:47.480 --> 00:17:50.619 persistent severe hypoxia and acidosis. This 00:17:50.619 --> 00:17:53.519 is a pacing emergency, no question. OK. We've 00:17:53.519 --> 00:17:56.200 established that slow rates kill cardiac output 00:17:56.200 --> 00:17:58.440 by not letting the heart fill enough times per 00:17:58.440 --> 00:18:02.240 minute. Now let's flip it and explore why excessively 00:18:02.240 --> 00:18:05.339 fast rates are equally catastrophic. Let's talk. 00:18:05.450 --> 00:18:09.789 Right, so tachycardia is just an abnormally fast 00:18:09.789 --> 00:18:12.349 heart rate for the child's age, and these rhythms, 00:18:12.430 --> 00:18:14.730 whether they start in the atria, the AV node, 00:18:14.730 --> 00:18:18.490 or the ventricles, they all risk acute cardiopulmonary 00:18:18.490 --> 00:18:21.109 compromise, especially if the child has some 00:18:21.109 --> 00:18:24.089 underlying cardiac issue. Let's really reinforce 00:18:24.089 --> 00:18:26.390 the two main physiological reasons why going 00:18:26.390 --> 00:18:29.230 too fast is so bad. The sources break this down 00:18:29.230 --> 00:18:31.170 beautifully. Okay, so first, and this is the 00:18:31.170 --> 00:18:34.069 big one, extremely rapid rates drastically shorten 00:18:34.069 --> 00:18:36.910 the duration of... Diastole is when the ventricles 00:18:36.910 --> 00:18:39.250 relax and fill up with blood for the next beat. 00:18:39.809 --> 00:18:42.170 Exactly. If diastole is too short, ventricular 00:18:42.170 --> 00:18:44.829 filling is just inadequate. that crushes your 00:18:44.829 --> 00:18:47.329 stroke volume and therefore crushes your cardiac 00:18:47.329 --> 00:18:49.470 output. Okay, so that's problem number one. What's 00:18:49.470 --> 00:18:51.910 the second? Second, and this is so critical, 00:18:52.369 --> 00:18:54.730 coronary perfusion, the blood flow to the heart 00:18:54.730 --> 00:18:57.710 muscle itself, happens primarily during diastole. 00:18:57.930 --> 00:19:01.349 So a prolonged rapid tachycardia means the heart 00:19:01.349 --> 00:19:04.130 is literally starving itself of oxygen at the 00:19:04.130 --> 00:19:06.250 exact moment it's being asked to work its absolute 00:19:06.250 --> 00:19:08.750 hardest. That's a perfect way to put it. It creates 00:19:08.750 --> 00:19:12.269 a severe myocardial oxygen demand supply mismatch. 00:19:12.569 --> 00:19:15.490 In kids, and especially infants, a prolonged 00:19:15.490 --> 00:19:18.490 SVT can rapidly just tire out the heart muscle 00:19:18.490 --> 00:19:21.789 leading straight to myocardial dysfunction, congestive 00:19:21.789 --> 00:19:24.369 heart failure, and cardiogenic shock. Which is 00:19:24.369 --> 00:19:26.569 why immediate rate control is absolutely paramount. 00:19:26.640 --> 00:19:29.119 It is. So our first step when we see a tachycardia 00:19:29.119 --> 00:19:32.779 on the monitor is to classify it by its QRS complex 00:19:32.779 --> 00:19:36.180 width. Yep. We use a cutoff of 0 .09 seconds. 00:19:36.519 --> 00:19:38.740 If the QRS is less than that, we call it narrow 00:19:38.740 --> 00:19:41.200 complex. That means the impulse originated above 00:19:41.200 --> 00:19:43.220 the ventricles and traveled down the normal fast 00:19:43.220 --> 00:19:45.119 highway, the bundle branches. So that's things 00:19:45.119 --> 00:19:47.700 like sinus tachycardia, SVT, atrial flutter. 00:19:47.839 --> 00:19:51.039 Correct. If the QRS is wider than 0 .09 seconds, 00:19:51.059 --> 00:19:53.859 it's a wide complex rhythm. And that's generally 00:19:53.859 --> 00:19:56.740 either ventricular tachycardia, VT, or, and this 00:19:56.740 --> 00:19:59.940 is a critical distinction, an SVT with aberrant 00:19:59.940 --> 00:20:02.339 conduction. Okay, let's start with the one that 00:20:02.339 --> 00:20:06.900 causes the most diagnostic headaches. Sinus tachycardia, 00:20:07.000 --> 00:20:09.839 ST. This is a physiologic response we have to 00:20:09.839 --> 00:20:12.710 rule out first. We have to. Sinus tachycardia 00:20:12.710 --> 00:20:16.589 is a normal compensatory response. The SA node 00:20:16.589 --> 00:20:19.230 is firing faster because the body needs more 00:20:19.230 --> 00:20:21.609 cardiac output. There's a reason for it, like 00:20:21.609 --> 00:20:25.250 a fever or pain or fluid loss. It's not a pathological 00:20:25.250 --> 00:20:27.269 arrhythmia. You don't treat it with antiarrhythmic 00:20:27.269 --> 00:20:30.490 drugs. No. And misdiagnosing ST as SVT and giving 00:20:30.490 --> 00:20:32.670 the wrong drugs is one of the most common and 00:20:32.670 --> 00:20:35.470 dangerous pitfalls. So as the ER nurse, what 00:20:35.470 --> 00:20:37.829 are the ECG keys that tell you this fast rhythm 00:20:37.829 --> 00:20:40.710 is just ST? You have to look for beat to beat 00:20:40.710 --> 00:20:43.230 variability. The rate should fluctuate. It should 00:20:43.230 --> 00:20:45.849 change with activity, with pain, with crying, 00:20:45.990 --> 00:20:49.009 with stress. And critically, the rate is usually 00:20:49.009 --> 00:20:51.430 constrained. There's a ceiling. It's generally 00:20:51.430 --> 00:20:53.990 less than 220 beats per minute in infants and 00:20:53.990 --> 00:20:56.650 less than 180 in children. And you absolutely 00:20:56.650 --> 00:20:59.650 must see normal P waves before every single QRS. 00:21:00.049 --> 00:21:02.230 And the R to R interval, the space between the 00:21:02.230 --> 00:21:04.490 beats, is usually variable, not perfectly fixed. 00:21:04.569 --> 00:21:06.549 Not fixed, right. It speeds up. It slows down. 00:21:06.569 --> 00:21:08.599 It's responding to the body. So what are the 00:21:08.599 --> 00:21:10.359 common underlying causes we should be hunting 00:21:10.359 --> 00:21:13.920 for if we think it's ST? Oh, the list is long. 00:21:14.440 --> 00:21:18.920 Fever is huge. Pain, anxiety, hypovolemia, either 00:21:18.920 --> 00:21:22.200 from dehydration or hemorrhage, shock, like septic 00:21:22.200 --> 00:21:26.299 or hypovolemic shock, hypoxemia, trauma. Your 00:21:26.299 --> 00:21:28.880 job with ST is to find and aggressively treat 00:21:28.880 --> 00:21:31.119 that underlying cause. Give the fluids, give 00:21:31.119 --> 00:21:33.660 the Tylenol, fix the oxygenation problem. Exactly. 00:21:33.779 --> 00:21:36.019 You treat the patient, not the monitor. Okay, 00:21:36.079 --> 00:21:39.019 now let's turn to superventricular tachycardia, 00:21:39.539 --> 00:21:42.140 SVT, the pathological rhythm that's the great 00:21:42.140 --> 00:21:45.339 mimicker of SD. SVT is an abnormally fast rhythm 00:21:45.339 --> 00:21:47.299 that starts above the ventricles, and it's often 00:21:47.299 --> 00:21:49.599 caused by a reentry circuit. Think of it like 00:21:49.599 --> 00:21:51.619 a short circuit, often involving an accessory 00:21:51.619 --> 00:21:54.640 pathway or the AV node itself. And the hallmark 00:21:54.640 --> 00:21:57.259 of it is its paroxysmal nature. Meaning it has 00:21:57.259 --> 00:21:59.960 an abrupt onset and an abrupt termination, like 00:21:59.960 --> 00:22:01.960 flipping a switch. Exactly like flipping a switch 00:22:01.960 --> 00:22:05.299 on and then off. So how does the ECG scream SVT 00:22:05.299 --> 00:22:07.660 at you, especially when there's hemodynamic compromise? 00:22:08.019 --> 00:22:09.980 The signs are basically the inverse of what we 00:22:09.980 --> 00:22:13.910 see in ST. In SBT, there is no beat -to -beat 00:22:13.910 --> 00:22:16.650 variability. The rate is fixed, and it is relentless. 00:22:17.069 --> 00:22:19.730 And it typically meets or blows past those critical 00:22:19.730 --> 00:22:23.710 rate thresholds. The 22180 rule. Right. 220 per 00:22:23.710 --> 00:22:26.329 minute in infants or 0180 per minute in children. 00:22:26.890 --> 00:22:29.269 P waves are often completely unidentifiable, 00:22:29.430 --> 00:22:32.230 or they're buried inside the QRS, and that RR 00:22:32.230 --> 00:22:35.470 interval is dead constant. Those rate thresholds, 00:22:35.549 --> 00:22:38.289 the 220 and 180, those have to be the nurse's 00:22:38.289 --> 00:22:41.009 non -negotiable mental alarm bells. If a child 00:22:41.009 --> 00:22:43.549 crosses that line, you have to assume it's SVT 00:22:43.549 --> 00:22:45.890 until you can prove it's not. You have to. Because 00:22:45.890 --> 00:22:48.670 a rate that fast simply does not allow for adequate 00:22:48.670 --> 00:22:51.609 diastolic filling. Low cardiac output is guaranteed 00:22:51.609 --> 00:22:53.930 eventually. Let's talk about the clinical presentation 00:22:53.930 --> 00:22:57.279 of SVT. How do we spot that impending CHF or 00:22:57.279 --> 00:22:59.019 shock at the bedside? You're looking for things 00:22:59.019 --> 00:23:01.680 like irritability, a refusal to feed, or just 00:23:01.680 --> 00:23:04.119 profound lethargy. And because that heart is 00:23:04.119 --> 00:23:06.660 getting so tired, you start to see signs of congestive 00:23:06.660 --> 00:23:08.519 heart failure. So things like rapid breathing. 00:23:08.920 --> 00:23:12.299 Rapid breathing, grunting. You might hear crackles 00:23:12.299 --> 00:23:14.640 when you listen to their lungs, hepatomegaly 00:23:14.640 --> 00:23:17.920 from fluid backing up. An older child might actually 00:23:17.920 --> 00:23:20.180 be able to tell you they feel severe palpitations 00:23:20.180 --> 00:23:22.380 or like they're going to pass out. And prolonged 00:23:22.380 --> 00:23:26.259 SVT. even in a kid with a structurally normal 00:23:26.259 --> 00:23:30.019 heart is a true medical emergency. It absolutely 00:23:30.019 --> 00:23:33.680 is. Okay, this brings us to the ST versus SVT 00:23:33.680 --> 00:23:36.880 quick comparison. This is the most common diagnostic 00:23:36.880 --> 00:23:39.740 hurdle in Pellas. We need to be able to apply 00:23:39.740 --> 00:23:42.079 that mental table really, really quickly. Let's 00:23:42.079 --> 00:23:44.519 focus on the practical differences. Picture this. 00:23:44.900 --> 00:23:46.619 A child comes in, they're crying, they have a 00:23:46.619 --> 00:23:48.839 fever, heart rate is 190. When you finally get 00:23:48.839 --> 00:23:51.680 them settled down, the rate drops to 160. That 00:23:51.680 --> 00:23:54.420 rate variability... That strongly suggests ST. 00:23:54.539 --> 00:23:56.920 It's responding to the stimulus. Exactly. Now, 00:23:57.039 --> 00:23:58.740 same child, but they're quiet, they're limp, 00:23:58.859 --> 00:24:00.759 they look mottled, and the rate is a constant 00:24:00.759 --> 00:24:03.079 230 beats per minute. There's no fluctuation, 00:24:03.319 --> 00:24:06.619 no visible P waves. That fixed, relentless rate, 00:24:06.960 --> 00:24:09.160 plus the fact that it's over the threshold, tells 00:24:09.160 --> 00:24:12.579 us this has to be SVT. And the clinical implication 00:24:12.579 --> 00:24:15.339 of getting that right is enormous. If you suspect 00:24:15.339 --> 00:24:18.559 ST, your first move is an IV fluid challenge 00:24:18.559 --> 00:24:21.460 and antipyretics. But if you suspect SVT? You 00:24:21.460 --> 00:24:24.400 are immediately preparing the synchronized tardioverter 00:24:24.400 --> 00:24:27.799 pads and drawing up adenosine. Getting it wrong 00:24:27.799 --> 00:24:31.000 wastes crucial time, or even worse, leads to 00:24:31.000 --> 00:24:33.759 giving the wrong drug or an unnecessary shock. 00:24:33.980 --> 00:24:36.359 We should probably briefly touch on atrial flutter. 00:24:36.480 --> 00:24:39.119 It's another narrow complex rhythm, but we usually 00:24:39.119 --> 00:24:41.299 see it in specific populations, right? We do. 00:24:41.420 --> 00:24:43.619 You typically see atrial flutter in kids who 00:24:43.619 --> 00:24:45.640 have pre -existing congenital heart disease or 00:24:45.640 --> 00:24:48.319 after they've had cardiac surgery. It's a rapid 00:24:48.319 --> 00:24:50.440 reentry circuit, but it's contained within the 00:24:50.440 --> 00:24:52.660 atrium. And the ECG hallmark is that classic. 00:24:52.980 --> 00:24:55.480 Sawtooth pattern of P waves. The atrial rate 00:24:55.480 --> 00:24:58.740 is just incredibly fast, over 300 a minute, but 00:24:58.740 --> 00:25:00.880 the ventricular rate is usually slower because 00:25:00.880 --> 00:25:03.420 the AV node blocks some of those signals. So 00:25:03.420 --> 00:25:06.059 you might get a 2 .1 or a 4 .1 block. Right, 00:25:06.200 --> 00:25:07.960 which means the ventricular rate might actually 00:25:07.960 --> 00:25:11.039 be near normal or only mildly tachycardic, which 00:25:11.039 --> 00:25:13.880 can be deceiving. OK, now let's move to the most 00:25:13.880 --> 00:25:18.200 potentially unstable rhythms, the wide complex 00:25:18.200 --> 00:25:21.119 rhythms, starting with ventricular tachycardia. 00:25:21.319 --> 00:25:24.839 VT. VT is, I mean, it's the definition of electrical 00:25:24.839 --> 00:25:27.359 inefficiency. The impulse is generated down in 00:25:27.359 --> 00:25:29.819 the ventricle, so it bypasses that super -fast 00:25:29.819 --> 00:25:31.940 specialized conduction system. Which leads to 00:25:31.940 --> 00:25:35.220 those wide, bizarre -looking QRS complexes, wider 00:25:35.220 --> 00:25:38.160 than 0 .09 seconds. Yep. And the rate is usually 00:25:38.160 --> 00:25:41.519 at least 120, but often it gets up to 200 or 00:25:41.519 --> 00:25:44.400 even more. And why does VT cause such immediate 00:25:44.400 --> 00:25:47.539 hemodynamic compromise? It's because that electrical 00:25:47.539 --> 00:25:49.900 impulse is traveling slowly, muscle cell to muscle 00:25:49.900 --> 00:25:51.740 cell, through the ventricles. The contraction 00:25:51.740 --> 00:25:53.640 is disorganized and it's inefficient. That just 00:25:53.640 --> 00:25:55.599 tanks your stroke volume. And the rapid rate 00:25:55.599 --> 00:25:57.980 on top that makes the diastolic filling problem 00:25:57.980 --> 00:26:00.160 even worse. It's a double hit to your cardiac 00:26:00.160 --> 00:26:02.980 output. And on top of all that, VT can degenerate 00:26:02.980 --> 00:26:05.460 into pulseless VT or ventricular fibrillation 00:26:05.460 --> 00:26:08.480 at any moment. What are the primary ECG keys 00:26:08.480 --> 00:26:11.339 for recognizing VT? The rate is fast and it's 00:26:11.339 --> 00:26:14.019 typically regular. The cuirous complex is wide. 00:26:14.269 --> 00:26:17.529 And the P waves are either gone, you can't see 00:26:17.529 --> 00:26:19.569 them, or you can see them firing independently 00:26:19.569 --> 00:26:22.569 of the QRS. That's your AV dissociation again. 00:26:23.029 --> 00:26:25.190 But the big clinical question you're often faced 00:26:25.190 --> 00:26:28.990 with in the moment is, is this really VT or is 00:26:28.990 --> 00:26:33.089 it an SVT with aberrancy? And that distinction, 00:26:33.450 --> 00:26:36.529 SVT with aberrancy versus VT, is one of the biggest 00:26:36.529 --> 00:26:39.490 highest stakes pitfalls in peril. How do you 00:26:39.490 --> 00:26:41.750 tell them apart? So how do we? This is where 00:26:41.750 --> 00:26:43.490 you have to look for really nuanced findings. 00:26:44.009 --> 00:26:46.230 If it's an SVT that's just traveling down an 00:26:46.230 --> 00:26:48.769 already injured or blocked bundle patch, that's 00:26:48.769 --> 00:26:51.170 aberrancy, you can still sometimes see clues 00:26:51.170 --> 00:26:54.009 of its supraventricular origin. Like some RR 00:26:54.009 --> 00:26:55.869 variability, or you might spot a P wave that 00:26:55.869 --> 00:26:58.109 does conduct every now and then. Right. In true 00:26:58.109 --> 00:27:00.410 VT, you're looking for definitive signs of AV 00:27:00.410 --> 00:27:03.009 dissociation or things called fusion beats or 00:27:03.009 --> 00:27:04.890 capture beats, which are just more proof that 00:27:04.890 --> 00:27:07.329 the atria and ventricles are not talking. But 00:27:07.329 --> 00:27:10.009 in the middle of a code. in that chaos if you 00:27:10.009 --> 00:27:12.069 can't immediately tell the difference and the 00:27:12.069 --> 00:27:14.589 patient is unstable. The Pallas algorithm is 00:27:14.589 --> 00:27:17.950 crystal clear. If a wide complex tachycardia 00:27:17.950 --> 00:27:20.750 is causing hemodynamic compromise, you treat 00:27:20.750 --> 00:27:23.309 it as the most dangerous option. You treat it 00:27:23.309 --> 00:27:25.970 as VT until you can prove otherwise. Because 00:27:25.970 --> 00:27:29.190 VT requires immediate electrical or pharmacological 00:27:29.190 --> 00:27:31.450 intervention. Immediately. Let's talk about the 00:27:31.450 --> 00:27:34.569 causes of VT. When you see that rhythm on the 00:27:34.569 --> 00:27:36.900 strip, What should the nurse be anticipating 00:27:36.900 --> 00:27:39.940 in terms of diagnostics? When you see VT, it 00:27:39.940 --> 00:27:41.779 strongly suggests there's a severe underlying 00:27:41.779 --> 00:27:44.200 problem. It could be congenital heart disease, 00:27:44.420 --> 00:27:48.259 like Long QT syndrome, or a significant cardiomyopathy 00:27:48.259 --> 00:27:51.579 or myocarditis. But crucially, from an ER perspective, 00:27:51.799 --> 00:27:54.240 you have to anticipate the need to treat severe 00:27:54.240 --> 00:27:57.579 electrolyte disturbances, hypokalemia, hyperkalemia, 00:27:57.759 --> 00:28:00.390 hypocalcemia, and drug toxicity. Things like 00:28:00.390 --> 00:28:03.369 tricyclic adidepressants. Tricyclics, methamphetamines. 00:28:03.450 --> 00:28:06.029 When you see a wide complex tachycardia, your 00:28:06.029 --> 00:28:08.170 immediate thought process should be, draw a chemistry 00:28:08.170 --> 00:28:10.690 panel and a toxicology screen right now. OK, 00:28:10.849 --> 00:28:12.970 finally, let's cover that visually distinct and 00:28:12.970 --> 00:28:16.150 highly dangerous variant of VT, polymorphic VT, 00:28:16.670 --> 00:28:19.710 or torsades de pointes. Torsades is... I mean, 00:28:19.950 --> 00:28:22.009 it's visually unmistakable once you've seen it. 00:28:22.210 --> 00:28:24.349 The QRS complexes look like they're twisting 00:28:24.349 --> 00:28:27.009 or rotating around the isoelectric line. They 00:28:27.009 --> 00:28:28.869 change their polarity and their amplitude. That's 00:28:28.869 --> 00:28:30.450 where the name comes from, turning on a point. 00:28:30.910 --> 00:28:33.410 And the rate is usually extremely fast and often 00:28:33.410 --> 00:28:36.150 irregular? Very fast and very unstable. What 00:28:36.150 --> 00:28:38.710 is the critical clinical association for torsides? 00:28:38.789 --> 00:28:40.599 What do we have to know? You have to know that 00:28:40.599 --> 00:28:43.099 it is almost always associated with a prolonged 00:28:43.099 --> 00:28:45.779 QT interval in the patient's preceding sinus 00:28:45.779 --> 00:28:49.339 rhythm. This rhythm is extremely unstable and 00:28:49.339 --> 00:28:52.500 can degrade into V -fib in a heartbeat. And this 00:28:52.500 --> 00:28:54.859 rhythm has a very specific pharmaceutical treatment 00:28:54.859 --> 00:28:57.359 that the ER nurse absolutely has to be ready 00:28:57.359 --> 00:29:00.140 for. It does. The causes are often things like 00:29:00.140 --> 00:29:03.000 congenital long QT syndromes, hypomagnesemia, 00:29:03.200 --> 00:29:06.119 hypokalemia, or certain drug toxicities. And 00:29:06.119 --> 00:29:08.539 since low magnesium is such a common acquired 00:29:08.539 --> 00:29:11.440 cause, the specific intervention for torsides 00:29:11.440 --> 00:29:14.039 is often the immediate administration of magnesium 00:29:14.039 --> 00:29:16.519 sulfate. Alongside defibrillation if they become 00:29:16.519 --> 00:29:19.140 pulseless. Of course. All right. We've laid out 00:29:19.140 --> 00:29:20.660 the foundational knowledge. We've gone through 00:29:20.660 --> 00:29:23.279 the ECG patterns. Here's where it gets really 00:29:23.279 --> 00:29:26.059 interesting. For that ER nurse who's prepping 00:29:26.059 --> 00:29:29.240 for pills, how does mastering all of these distinctions 00:29:29.240 --> 00:29:32.559 actually translate into running a successful, 00:29:32.839 --> 00:29:35.279 organized, and time -efficient resuscitation? 00:29:35.480 --> 00:29:38.019 The power of accurate rhythm recognition is all 00:29:38.019 --> 00:29:40.559 about anticipation. It lets the nurse move beyond 00:29:40.559 --> 00:29:42.400 just waiting for an order and lets them start 00:29:42.400 --> 00:29:44.700 executing all the preparatory steps. Like drawing 00:29:44.700 --> 00:29:46.920 up meds, setting up equipment. Exactly. Drawing 00:29:46.920 --> 00:29:49.319 up meds, setting the defib parameters, gathering 00:29:49.319 --> 00:29:52.000 specific labs. You can do all of that simultaneously 00:29:52.000 --> 00:29:54.430 with the provider's assessment. And that saves 00:29:54.430 --> 00:29:57.130 seconds, and those seconds define outcomes. Let's 00:29:57.130 --> 00:29:59.109 use a couple of concrete scenarios to really 00:29:59.109 --> 00:30:01.309 illustrate that rapid -fire decision process. 00:30:01.910 --> 00:30:04.230 Scenario one, a toddler comes in, heart rate 00:30:04.230 --> 00:30:07.670 is 170, they're hypotensive, modeled, and lethargic. 00:30:08.150 --> 00:30:11.130 The monitor shows wide, regular QRS complexes, 00:30:11.589 --> 00:30:14.910 no identifiable P waves. Yeah. Okay. Unstable, 00:30:15.029 --> 00:30:17.789 wide, complex tachycardia. We have to assume 00:30:17.789 --> 00:30:20.799 VT. So your immediate action, knowing how serious 00:30:20.799 --> 00:30:24.319 VT is, is to secure the ABCs, of course. But 00:30:24.319 --> 00:30:26.400 you're specifically anticipating the electrical 00:30:26.400 --> 00:30:28.559 and the toxicological interventions. So you're 00:30:28.559 --> 00:30:30.640 confirming the pads are on? You confirm the synchronized 00:30:30.640 --> 00:30:32.599 cardioversion pads are placed. You make sure 00:30:32.599 --> 00:30:36.220 the energy dose, 0 .5 to one joule per kilo to 00:30:36.220 --> 00:30:38.400 start, is dialed in. And while you're putting 00:30:38.400 --> 00:30:40.579 in that IV, you are drawing immediate labs for 00:30:40.579 --> 00:30:42.880 potassium, magnesium, and a tox screen. And you're 00:30:42.880 --> 00:30:45.440 already thinking about the meds? You are proactively 00:30:45.440 --> 00:30:48.039 preparing an amidurone or a lidocaine infusion. 00:30:47.950 --> 00:30:51.210 the rhythm on the monitor dictated all of those 00:30:51.210 --> 00:30:53.789 preparatory steps immediately. Okay, scenario 00:30:53.789 --> 00:30:56.670 two. A six -month -old infant comes in with a 00:30:56.670 --> 00:31:00.109 104 -degree fever. Heart rate is 210. It's regular 00:31:00.109 --> 00:31:02.309 narrow complex. The P waves are almost hidden. 00:31:02.769 --> 00:31:04.990 When the nurse goes to place an oral temp, the 00:31:04.990 --> 00:31:07.349 rate drops for just a second to 180, and then 00:31:07.349 --> 00:31:09.809 climbs right back up to 210. Okay, that drop 00:31:09.809 --> 00:31:12.579 in rate, even if it was just transient? That's 00:31:12.579 --> 00:31:14.700 a subtle clue that there might be some variability. 00:31:15.519 --> 00:31:18.059 However, the rate is persistently close to that 00:31:18.059 --> 00:31:21.460 220 threshold. The P waves are absent. Clinically, 00:31:21.680 --> 00:31:24.319 you cannot rule out SVT. Especially since the 00:31:24.319 --> 00:31:26.460 signs of compromise can overlap so much with 00:31:26.460 --> 00:31:28.319 fever and sepsis. You can't tell the difference 00:31:28.319 --> 00:31:30.980 sometimes. So the nurse's action has to be immediate 00:31:30.980 --> 00:31:34.059 preparation for adenosine push and flush. Let's 00:31:34.059 --> 00:31:36.039 detail that adenosine prep because the nursing 00:31:36.039 --> 00:31:38.500 technique is so crucial and so time sensitive. 00:31:38.650 --> 00:31:41.250 It absolutely is. Adenosine has a half -life 00:31:41.250 --> 00:31:44.049 of just a few seconds. So the nurse has to establish 00:31:44.049 --> 00:31:46.609 two lines if possible, or have everything ready 00:31:46.609 --> 00:31:50.109 at one. You need a proximal IV line for the rapid 00:31:50.109 --> 00:31:52.269 push of the adenosine, and you need a separate 00:31:52.269 --> 00:31:54.910 syringe ready for a rapid aggressive saline flush. 00:31:55.049 --> 00:31:57.670 At least five to ten millis. At least. The medication 00:31:57.670 --> 00:31:59.869 has to be pushed as fast as you can, followed 00:31:59.869 --> 00:32:02.450 immediately by that flush, and you have to elevate 00:32:02.450 --> 00:32:04.730 the limb to get the drug to the central circulation 00:32:04.730 --> 00:32:07.849 before it metabolizes. If you recognize SVT, 00:32:07.950 --> 00:32:09.750 who are setting the sequence up while someone 00:32:09.750 --> 00:32:12.130 else is attempting vagal maneuvers. Now, let's 00:32:12.130 --> 00:32:14.650 flip that. What if the heart rate was on 70, 00:32:15.069 --> 00:32:17.589 the child was screaming, the QRS was narrow, 00:32:17.910 --> 00:32:20.509 but the rate slowed down predictably every time 00:32:20.509 --> 00:32:22.509 they paused to take a breath? That predictable 00:32:22.509 --> 00:32:24.950 variability and the fact that the rate is staying 00:32:24.950 --> 00:32:28.829 below that critical 180 or 220 threshold, that 00:32:28.829 --> 00:32:31.579 points very strongly to sinus tachycardia. And 00:32:31.579 --> 00:32:34.240 your actions shift completely. Completely. You 00:32:34.240 --> 00:32:37.579 hold the adenosine, you prioritize rapid temperature 00:32:37.579 --> 00:32:39.980 reduction antipyretics, maybe cooling blankets, 00:32:40.420 --> 00:32:43.059 and a fluid assessment. You anticipate the need 00:32:43.059 --> 00:32:45.660 for an IV fluid bolus to treat the dehydration 00:32:45.660 --> 00:32:48.279 that the fever caused. You're treating the cause, 00:32:48.579 --> 00:32:50.819 not the rhythm. Let's connect bradycardia. Back 00:32:50.819 --> 00:32:53.619 to the bedside. You said symptomatic bradycardia 00:32:53.619 --> 00:32:56.220 is the pre -arrest state that's driven by hypoxia. 00:32:56.339 --> 00:32:59.140 Right. And when you see that symptomatic bradycardia, 00:32:59.259 --> 00:33:01.920 that heart rate under 60 with poor perfusion, 00:33:02.400 --> 00:33:05.480 the nurse's ABC flow is absolutely non -negotiable. 00:33:05.619 --> 00:33:08.160 First thing is airway, oxygenation, and ventilation. 00:33:08.380 --> 00:33:10.740 You have to max out their oxygen delivery. You 00:33:10.740 --> 00:33:14.220 have to. You ensure maximum oxygen delivery and 00:33:14.220 --> 00:33:16.420 effective ventilation before you even think about 00:33:16.420 --> 00:33:19.769 rhythm drugs. If and only if that bradycardia 00:33:19.769 --> 00:33:22.829 persists despite good ventilation and 100 % oxygen. 00:33:23.089 --> 00:33:25.470 That is the trigger. That is the clear trigger 00:33:25.470 --> 00:33:28.339 for the nurse to initiate CPR. And what's the 00:33:28.339 --> 00:33:30.299 common pitfall here that the nurse has to avoid? 00:33:30.519 --> 00:33:32.839 Wasting time waiting for medications. If you 00:33:32.839 --> 00:33:35.359 see a persistent bradycardia at 50 with poor 00:33:35.359 --> 00:33:38.440 perfusion, that child is effectively in cardiac 00:33:38.440 --> 00:33:42.259 arrest. CPR is what provides the artificial circulation 00:33:42.259 --> 00:33:44.319 they need to perfuse their own coronaries in 00:33:44.319 --> 00:33:46.460 their brain. Trying to draw up atropine when 00:33:46.460 --> 00:33:48.720 the kid really just needs you to bag them better 00:33:48.720 --> 00:33:51.420 or start compressions is a critical delay. It's 00:33:51.420 --> 00:33:53.960 a critical delay. Recognition dictates. Secure 00:33:53.960 --> 00:33:55.839 the airway first, then start compressions if 00:33:55.839 --> 00:33:58.099 the rate doesn't come up. This entire discussion 00:33:58.099 --> 00:34:01.140 just reinforces that the PLS material, it's not 00:34:01.140 --> 00:34:03.539 just a sequence of boxes in an algorithm, it's 00:34:03.539 --> 00:34:05.960 a roadmap that's built on this underlying path 00:34:05.960 --> 00:34:08.639 of physiology. We have to master the differences 00:34:08.639 --> 00:34:12.019 between Mobitz type I and II, between ST and 00:34:12.019 --> 00:34:15.059 SVT variability, and between the wide versus 00:34:15.059 --> 00:34:18.489 the narrow QRS complex. Exactly. And mastering 00:34:18.489 --> 00:34:21.789 that differentiation based on all the ECG characteristics 00:34:21.789 --> 00:34:23.969 we've discussed, that's the hardest part, but 00:34:23.969 --> 00:34:26.550 it's also the most impactful challenge. In the 00:34:26.550 --> 00:34:29.230 middle of all that chaos, the rhythm strip is 00:34:29.230 --> 00:34:31.710 your most objective piece of data. Tells you 00:34:31.710 --> 00:34:33.449 what to do next. It tells you whether you should 00:34:33.449 --> 00:34:36.110 be preparing fluids or synchronizing the electricity 00:34:36.110 --> 00:34:38.630 or checking the electrolytes. The question you 00:34:38.630 --> 00:34:41.800 have to ask yourself is... What stands out to 00:34:41.800 --> 00:34:45.199 you in that chaos? Is it the fixed unrelenting 00:34:45.199 --> 00:34:49.039 pace of SVT, or is it that subtle rate change 00:34:49.039 --> 00:34:52.219 of ST? That is the question that guides the entire 00:34:52.219 --> 00:34:55.159 code. That distinction variability versus a fixed 00:34:55.159 --> 00:34:58.039 rate, that really is the mental cornerstone for 00:34:58.039 --> 00:35:00.719 managing pediatric tachycardias. It is. That 00:35:00.719 --> 00:35:03.500 was an incredibly detailed deep dive into the 00:35:03.500 --> 00:35:06.039 foundations of Pell Rhythmia Recognition. It 00:35:06.039 --> 00:35:09.460 was really tailored for the ER nurse. Let's recap 00:35:09.460 --> 00:35:11.300 the four most critical takeaways that you need 00:35:11.300 --> 00:35:13.400 to internalize for your next shift. Okay, number 00:35:13.400 --> 00:35:15.840 one, physiological constraint. Always remember 00:35:15.840 --> 00:35:17.900 that heart rate is the primary driver of cardiac 00:35:17.900 --> 00:35:20.760 output in infants and young kids. Any significant 00:35:20.760 --> 00:35:23.159 deviation is immediately life -threatening. Number 00:35:23.159 --> 00:35:26.480 two, bradycardia priority. Symptomatic bradycardia, 00:35:26.539 --> 00:35:28.659 that heart rate less than 60 with compromise, 00:35:29.159 --> 00:35:32.519 is almost always secondary to hypoxia. Your first 00:35:32.519 --> 00:35:35.260 action is to secure the airway and maximize ventilation. 00:35:35.550 --> 00:35:38.110 If it persists, start CPR immediately. Number 00:35:38.110 --> 00:35:40.510 three, the big one. Tachycardia differentiation. 00:35:40.869 --> 00:35:42.710 You must be able to swiftly tell the difference. 00:35:43.409 --> 00:35:46.070 Is it sinus tachycardia, which is a normal response 00:35:46.070 --> 00:35:48.030 that has rate variability and a rate generally 00:35:48.030 --> 00:35:52.809 below 220 or 180? Or is it SVT or VT, a pathological 00:35:52.809 --> 00:35:55.210 rhythm with a fixed relentless rate that often 00:35:55.210 --> 00:35:57.769 meets or exceeds those thresholds? And finally, 00:35:57.909 --> 00:36:01.519 number four. Wide complex warning. Ventricular 00:36:01.519 --> 00:36:04.480 tachycardia is high risk. Recognizing a wide 00:36:04.480 --> 00:36:06.780 QRS complex should immediately alert you to the 00:36:06.780 --> 00:36:09.280 possibility of underlying heart disease, toxicology, 00:36:09.659 --> 00:36:12.039 or severe electrolyte problems like with potassium 00:36:12.039 --> 00:36:14.739 or magnesium. This foundational knowledge, it 00:36:14.739 --> 00:36:16.559 really does transform you from someone who's 00:36:16.559 --> 00:36:18.760 just following orders into a proactive clinical 00:36:18.760 --> 00:36:21.300 leader who can anticipate that next step. We 00:36:21.300 --> 00:36:23.840 really encourage you to practice applying these 00:36:23.840 --> 00:36:26.820 ECG characteristics and these differentiators 00:36:26.820 --> 00:36:29.159 mentally. Don't just memorize the treatments. 00:36:29.260 --> 00:36:32.159 Understand why a certain rhythm leads to a specific 00:36:32.159 --> 00:36:36.099 treatment. Keep those PR intervals, QRS widths, 00:36:36.159 --> 00:36:38.900 and RR variability cues at the top of your mind 00:36:38.900 --> 00:36:41.679 as you move on to mastering the specific Pyle 00:36:41.679 --> 00:36:43.940 algorithms. Thank you so much for joining us 00:36:43.940 --> 00:36:46.199 on this deep dive into Pyle's foundations. We 00:36:46.199 --> 00:36:48.079 wish you the very best in your preparation and, 00:36:48.079 --> 00:36:49.960 of course, in your practice. Until next time.