Cardiac Nursing - All you need to know

 

Okay, in this article, we re just kinda condense and talk very briefly about some of the things that weren t covered in the disease specific videos relating to the cardiac system and some of the things that you really need to know. So, this is gonna bring about a lot of kind of electic is gonna seem a little bit random but we re gonna talk about the things that you really need to know for NCLEX just as quick points, okay? So, first of all, heart rate. What is a normal heart rate? Well, we all know that normal heart rate is 60-100. Sinus tachycardia is gonna be over 100 beats per minute and Sinus bradycardia is gonna be less than 60 beats per minute. And the way that we re obviously gonna assess that is gonna be through our EKG, we have our P, Q, R, S, and T. This is gonna be one complete cardiac cycle. This is the mechanical representation of one complete cardiac cycle and we re looking, hoping that our patients are between 60 - 100 beats per minute. That s gonna be normal. Sinus tachy is gonna be greater than 100. Sinus brady is gonna be less than 60. Okay. So, now very quickly, let s talk about the vascular system. Hopefully, this is not new information for you at all. But, our vascular system consists of arteries and veins, then there s venules, arterioles, and there s capillaries, okay? So, basically, we have our heart, and coming out of our heart is gonna be arteries and then it gonna go to arterioles which are gonna be a little bit smaller, and then we re gonna have this capillary network, okay, within different organs. And then, we re gonna have our venules, and then we re gonna have our veins bringing it back to the heart. Easy way to remember this is arteries take blood away and venules or veins bring blood back. I remember that because I learned Spanish back in the day and viene means to come. So, V, Viene , comes back to the heart. A for away, arteries and then again you have your arterioles and this is gonna be our capillary bed. 

And the capillary network is really what s gonna be within organs, so like for an example, here s a kidney, here s a kidney, or a pancreas, there s kidney right there, then you re also gonna have your liver, and those are all gonna be, have all these capillaries, or these arteries and veins within those. So, that s kinda your capillaries are gonna branch out and perfuse all those different areas. And here s lungs, of course. And, so, on this picture here, the red is going to indicate arteries and your blue is gonna indicate a vein. Okay, here s your aorta, and then here s your vena cava. Okay, so that s very simple overview of the vascular system. Now, when we have a patient who is suspected of having a heart attack, one thing that we re gonna run is we re gonna run with our cardiac markers. Another way to refer this is gonna be CIP s: Cardiac Injury Profile. Okay, Cardiac Injury Profile is going to be a set of a few labs that we run to determine the extent or the presence of cardiac damage. That s going to consist of Troponin, that s gonna be Troponin I and Troponin T, CK-MB and Myoglobin. I know we talked about this in our Myocardial Infarction lecture. But very briefly, Troponin is going to be your most sensitive to cardiac damage, however, it takes 12 hours to peak. Your CK-MB is gonna be a little bit less sensitive and it takes a little bit longer than your Troponins. Myoglobin, very low specificity to infarction because this can indicate damage to muscles in general. It does peaks the fastest but very low specificity. So the number that we re gonna be concerned about are the Troponins, and most of all, I mean, in my hospital, the number that we re really looking at is our Troponin I. 

Okay, if our Troponin I is elevated, then that s an indicative of infarction. Okay, specially when we can match that up with an EKG, if we have an EKG that shows like an ST Elevation, and we have Troponins that are elevated, the patient is having a heart attack. If we have a Non-STEMI but we have our elevated Troponins, we can also determine that they maybe having a heart attack. So, Cardiac Labs. These are gonna be some of the labs you re going to be concerned about with cardiac damage. First of all is gonna be potassium, a normal potassium is 3.5 - 5. We know that hypokalemia, so less than 3.5 can lead to ventricular dysrhythmias, increased digoxin toxicity if your patient is receiving digoxin, it can develop a U wave. Now, what a U wave is, is it s, so here s our normal, then there will be an additional wave here, this is gonna be our U wave and this is gonna show up with hypokalemia. This could also lead to ST depression. Again, ST depression, here s our, so ST depression is gonna look like that. So, Q, R, S, and T, so instead of ever really coming up, it will just go below our isoelectric line and that s gonna be ST depression. Hyperkalemia can lead to peaked T waves, so, what you ll see with your patient is they will have a T wave that s very high and maybe almost as high as your Q, R, S. And then, you ll also have the widened QRS and then it could lead to ventricular dysrhythmias as well. And again, if this QRS continues to widen, that s gonna lead to severe ventricular arrythmias and then you ll gonna have your peaked T waves. So, what I would do, if you have a patient that s on 5-lead continuous cardiac monitoring or whatever, if you start noticing that these T waves are elevating, you know, cause your normal T waves is gonna be way down here, we notice that these T waves start to elevate, what I would do, is I would just kinda call a physician and say Hey, you know, I noticed the EKG is getting a little bit funky. We re getting these changes in the T wave. Do you mind if I run, just get like a CBC or a BNP, you know. Another lab we re gonna look about at is Hematocrit. Hematocrit is basically percent of RBC s in the blood. It s different for males and females. But as that number goes up, as our percent of red blood cells goes up, that s gonna be indicative of dehydration. Why is that? Well, you know, part of our blood, only a portion of our blood is red blood cells, as you can see here, it s 30 - 50 % or so, and the rest is gonna be different fluids and things. So, if that continues to go up, you know, and we re at 60 for our hematocrit, that s gonna mean there s less of the other fluids which shows that we are dehydrated. On the other hand, if our hematocrit goes down, hemoglobin goes down, that can be indicative of anemia. Another lab that you re gonna look at for your cardiac patients is gonna be lipids, it s gonna be total cholesterol, you want to have under 200 mg/dL, LDL, that s our bad cholesterol, you want it under 130, HDL, happy, high density lipoproteins, you want that between 30 and 70, and that s our good cholesterol. Okay. A couple of the labs I did not write on here but I want you to remember are gonna be BNP, I know we talked about this with heart failure, that s brain natriuretic peptide, and what happens with that, as the ventricles stretch, as there s increase ventricular stretch, that s gonna release BNP into the system. Normal value should be under a 100. You might notice patients with heart failure have levels 4,000 and above. But anytime we get up over a 100, that s gonna be indicative of ventricular stretch and heart failure. What was another lab I want to talk about? BNP, that s really a big one, indicative of heart failure. Okay. Holter Monitoring. So, Holter Monitoring is important for patients who maybe have angina, whether it s stable or unstable or prinzmetal angina, because what this can do, as you can see here, this is a picture of a Holter monitoring. It can be worn on a patient, it s supposed to be worn in 24 hours and it can be worn under their clothes. And, it s kinda have this continuous EKG monitoring. What the patient needs to do is, it s going to store this data, it s going to store their EKG, and as they start to have chest pain, they need to write down the time they have chest pain and what they were doing. And what can happen from that is the physician can take that EKG print out and they can match it up with what the patient s activities were, and what was going on, and they can kinda give them a better idea of the angina, better idea of what s causing the abnormalities in their EKG. But that s basically Holter Monitoring. This patient or this picture should help you remember. While we re on this one, let s talk about too, about EKG placement. So, for our 5 Lead EKG, now, as you guys know, I don t like mnemonics, okay? The reason why I don t like mnemonics is because I believe that if you understand the process, if you understand what s going on, you re going to better understand and remember forever the process and exactly what s going on. So, as you can separate learning mnemonics from learning the systems and the processes, I think you can better understand. However, for EKG placement, I think that there s an easy way to remember the mnemonic because it is just color-based. So, we wanna have our white one, we have our green one, black, red, and brown. So, best way to remember this is white on right, so, white on right is the first thing to remember, we have white on right, and then you ll do SNOW over TREES and SMOKE over FIRE. 

Okay, so, white is snow, right? Green is the color of trees. Black is the color of smoke and smoke comes out over fire right? And so smoke rises over fire. So, white on right, and snow over trees, white over green, and then smoke over fire, our brown is our ground, and that s gonna go right in the middle. Alright. So, that s the best way to remember 5 Lead EKG placement. Last thing we wanna talk about here is cardiogenic shock. So, what happens with cardiogenic shock is the heart is unable to maintain effective cardiac output. This can be due to various reasons, heart failure, disruptions in the cardiac functions. And, so, what we re gonna see is, so, shock. What we need to understand really quickly though is shock is a decreased delivery of oxygen to the body. And so, as oxygen delivery is decreased and it s affected, our organs are not gonna be able to function appropriately. So, it s not necessarily low blood volume, necessarily what it is, is decreased delivery of oxygen to the tissues and then the tissues are not able to function without that oxygen. So, what happens with our heart, is, for whatever reason, our heart is not beating as it should, it s not maintaining effective cardiac output. Okay. Cardiac output is volume of blood out in 1 minute, okay? So, some of these reminds us is gonna be low urine output. Why is that? Well, we re not delivering enough oxygen to our kidneys, or enough blood to our kidneys, so, the kidneys are not able to work appropriately. We re gonna have low urine output. Low BP, obviously, low cardiac output. The thing we re gonna want to assess most with this is our CVP. Okay. The reason we assess CVP, what that tells us, is it tells us the right atrial preload and what right atrial preload basically tells us is it tells us the overall volume in the system. Okay. The system is our body, okay? Because what CVP is, is CVP tells us right atrial preload basically. It s really gonna tell us the preload in the right side of our heart. Okay. And if we know the preload of the right side of our heart, we basically know about how much volume is kinda in the system. So, what is preload? Preload is gonna be the stretch as the ventricles fills up, okay. So, as the volume comes in, the stretch, the pressure exerted on those as the volume fills up. Normal CVP is gonna be 2 - 8 mmHg. Okay, so, if you have a very high CVP, that means it s gonna be indicative of like hypervolemia etc., if you have a low CVP, that means we have a decrease in volume. Okay, so, a CVP of less than 2 or hovering around there is gonna be indicative of low volume. Okay. So, that might mean we need to supply more volume. However, if we have a CVP of greater than like 8, 6 or 8 or so, that s gonna mean we have high volume and volume is not our problem, okay? So, if the patient is ventilated, you wanna take the end expiration and you re gonna zero the transducer at the fourth intercostal space along the mid axillary line and that s the location of the right atrium. Okay, where is that at? So, mid axillary line is here under the armpit and then you re gonna wanna the fourth intercostal space. And you have a little transducer, so this will be going like in your jugular and then we re gonna end up with these wave forms and we want that to be 2-8 mmHg. Okay, so that s gonna tell us our CVP. Hopefully, that makes a little bit of sense about cardiogenic shock, we ll go into shock in greater detail later. But, that s really kinda what you need to know. You don t need a lot to know a lot about shock for NCLEX. If you start working in an ICU, that s gonna be a topic you re wanna come back to and visit quite often. If you have any questions, you guys, let us know. Those are some of the quick NCLEX points.