Blood Pressure – Vital Signs (Nursing)

00:00 Welcome to blood pressure in our vital signs series. So taking a look at our normal range, it's 120/80 mmHg is considered a normal blood pressure. So let's take a little bit deeper look about blood pressure and how we get those numbers. So when we're talking about blood pressure, we're talking about arterial blood pressure and this is the force that's exerted on the walls of those arteries by pulsing blood under the pressure from the heart.

00:34 So when we're talking about blood pressure, you got to remember 2 different pieces.

00:38 One of those being systolic. And when we're talking about the systolic pressure, this is the pressure during the ventricular contraction. Now, when we're talking about our diastolic pressure, this is the pressure during ventricular relaxation. So, this is going to look much like this when you take a blood pressure. You're going to have the systolic reading, which is what we may call the top number and the diastolic reading which what we may call the bottom number. And blood pressure is measured in mmHg. So again, your reading should look something like this. Now, when we're talking about factors affecting arterial blood pressure, we've got to consider first our stroke volume and our heart rate. So a stroke volume all this is is the volume of blood ejected by those ventricles, those bottom parts of the heart.

01:30 We're going to take that times our heart rate and we get something of what we call cardiac output. Now our cardiac output is going to help affect our blood pressure. It's going to either make it go up or down as well as our peripheral resistance. So let's talk about what peripheral resistance is. This is the resistance of the vessels to blood flow. So just kind of think about this way. If you have a vessel that constricts, that's a lot more resistance if you think about it. Right? If we have a certain amount of fluid going through and those vessels are smaller, there's a lot of resistance. Now, if a vessel is nice, wide, and open and we have the same amount of pressure going through, the resistance decreases. Therefore, our blood pressure would be lower. So again, when you're thinking about blood pressure, just know that cardiac output and peripheral resistance can either raise or lower your blood pressure. Some other things to consider about when we're talking about peripheral resistance is what we call our blood volume, blood viscosity, and those vessels how elastic they are. So a blood volume is exactly that, it's the amount of volume of blood you have circulating in your body. We need a certain amount to perfuse our organs. Now also, if our blood viscosity has changed such as how thick is our blood, meaning how many red blood cells are in that otherwise known as our hematocrit, this affects how thick our blood is and also can affect our blood pressure. And lastly, vessel elasticity. Just think about if someone maybe smokes for example, they can harden and restrict those vessels and that as well can affect our blood pressure. So, when you talk about blood pressure, the gold standard is of course the American Heart Association. So they set out guidelines of what we consider hypertension. Now, when you hear that word all we're talking about is high blood pressure.

03:30 So let's take a look at this graphic. So a normal blood pressure, if you remember, is the systolic where our top number is 120 over 80 which is our diastolic. That's a normal stater for our blood pressure and that's the goal we shoot for. However, patient's blood pressure could be a little bit higher, so anything above 120 or over 80 systolic when we start creeping up, we call that pre-hypertension. Now, this is an important number to know because if we start moving out of that 120/80 range, we start doing some modifiable risk factors as what we call that such as maybe we watch our salt intake, maybe we watch the type of diet that we're consuming to see if we can use those factors to lower our blood pressure for our patients. Now next, we have something what we call stage 1 hypertension.

04:26 So this is the beginning stages of classified hypertension, meaning our systolic blood pressure is 130–139, our diastolic is 80–89. So once we get here as stage 1 hypertension, this starts becoming a cause of concern for your healthcare provider because this can start affecting the structures of our heart. So here is where maybe we'll start integrating medications for your patient. Now stage 1 can advance to stage 2 if it's uncontrolled and we have not created any treatment or initiated treatment to lower that blood pressure back down to our green range of our normal range. So stage 2 hypertension is classified a systolic 140 mm and over and diastolic 90 mm and over. So just to compare those, systolic 140 mm and over and diastolic 90 mm and over. So just to compare those, see how much higher our blood pressure can get. And again, once we start in stage 2 hypertension, this is definitely a cause of concern, we can affect our heart structures, and the patient perfusion to the rest of their organs. Now, we just talked about the American Heart Association standards about hypertension. Now, let's talk about 2 really common issues that you may deal with your patient such as hypertension versus hypotension and the difference. So when we're talking about hypertension, this is much more common in the patient population you're going to see. And hypotension is a lot less common. So we're talking about hypertension. If you remember that's defined a systolic greater than 120 and our diastolic greater than 90. Now with hypotension, this is going to be lower than the patient's baseline or if the patient starts having symptoms. Hypotension for each patient can vary depending on what their trend and again what their baseline is. Now with hypertension, believe it or not, usually the patient's asymptomatic, meaning they feel actually okay and this is why you may hear it called the silent killer. This can affect perfusion and perfusion to our organs and our heart long term. Now, with hypotension, patients are typically much more symptomatic. They can experience pallor, clamminess, confusion. Now, if our patient's blood pressure is too low, our heart triggers say "Hey, we're not getting enough perfusion so we will start beating a lot faster and increase our heart rate." Now, if we don't have enough blood volume going to our organs, it could also affect our kidneys and decrease our urine output. Another type of hypotension that's important to be aware of is what we call orthostatic or postural hypotension. This is when a normotensive person develops symptoms when they have a very low blood pressure for when they go from lying down to sitting up. So we can assess this by obtaining a blood pressure and a pulse when the client is supine lying down then they go to sitting and then they go to standing. That's a very common method to assess for orthostatic hypotension. So we just talked briefly about hypertension versus hypotension. So there's a lot of factors that can affect our blood pressure. So let's start with one being age. You can imagine over time our peripheral vascular tone decreases, this is going to lessen the blood return to the heart. And again, our cardiac tone as well over time as we age can decrease which lowers the force of contraction and our cardiac output. Now next is stress. If you're watching this, you could be a nursing school and as you can imagine stress can definitely affect our blood pressure.

08:11 This is going to stimulate that sympathetic cystome if you remember that fight or flight piece which in turn can increase your heart rate, your cardiac output, and that vascular resistance. Another consideration is ethnicity. Now, ethnicity can predispose you to something like hypertension, for example. The patient can be doing everything right; eating a healthy diet, watching their salt intake, living a healthy lifestyle and exercising.

08:40 Just keep in mind that ethnicity can predispose a patient with high blood pressure issues.

08:46 Also know that with genders, higher blood pressure in males is often after puberty and also women after menopause. Now other factor to consider with blood pressure is just the variation of the day in our Circadian rhythms. So when we sleep, our bodies relax so typically our blood pressure is usually lower than when we wake up. And of course, there are all kind of medications out there to affect our blood pressure, some of them are going to constrict those vessels to increase the blood pressure because that's what we're trying to do for that patient. Sometimes, that blood pressure is way too high like those hypertension patients such as stage 1 or maybe stage 2. We may be giving them what we call antihypertensives to lower that blood pressure. And also, different medications like opioids, for example, for pain can also affect our blood pressure. So, let's talk about some what we call modifiable risk factors in regards to blood pressure. One of those being activity and weight. Now, if we exercise regularly, this can contribute to a lower blood pressure. Also our weight can affect our blood pressure as well such as obesity over time can predispose someone to high blood pressure otherwise known as hypertension. And also smoking guys. This is where that peripheral vascular resistance comes in because smoking directly affects the patient's vessels. This can produce vasoconstriction here, which of course increases the patient's blood pressure. And don't forget about diet. This one's a hard one. Right? Because it's really easy especially at nursing school and just the ease of the type of foods that we have available, that high salt and high sodium diets, processed foods can all affect our blood pressure. It will increase that blood pressure especially high amounts of caffeine. Now again, as you can imagine, all of these maybe factors that you may have during nursing school and it can also affect your blood pressure.

10:52 And don't forget excessive alcohol intake. This can also affect our blood pressure and raising it quite a bit to where we could go in to that, again stage 1 or stage 2 hypertension.

11:04 Now, let's take a look at risk factors. We have already talked briefly about things such as obesity, smoking, alcohol consumption, caffeine intake, and high salt diets. These are all what we call modifiable risk factors. Now when you hear this word, that only means that as a person, these are factors that we can control to reduce our risk of hypertension.

11:28 Also, there's non-modifiable risk factors to take into account. Now these are things, of course, that the patient can't do anything about. We definitely can't slow down our aging as much as some of us may want to do so. And also our gender, ethnicity, our family history also can predispose us to hypertension. So let's take a look at this image. This is what we call a sphygmomanometer. Now guys, that's a mouthful. Right? Really we just call this a blood pressure cuff. Now, I do want to point out a very important fact about this cuff that we see on the image. Now, this one's hooked up to the wall and you're going to see this a lot in your physician's office, for example, for routine check-up, but this is what we call a manual blood pressure cuff. Because it's not hooked up to any machine that is powered by battery, we are going to get our reading here by looking at our dial with the markings. And also you see the bulb at the bottom? We inflate this to obtain our reading. So this is why we call this a manual blood pressure cuff and it's going to be the most accurate. Now it's important when we're selecting a blood pressure cuff for our patient to look at size guidelines. So we've got to look at our patient's arm length and also the width of the cuff.

12:46 Nowadays it's really helpful that we have markings on a manual cuff. Most manual blood pressure cuffs that you see will have the same markings to help you for appropriate size for your patient. So you see this Y index line that you see running this way on the cuff on the image? That's going to help us know does it fall within the minimum and that maximum range markings. So that's really helpful because if it falls anywhere in between that line, we know this is the appropriate size for that patient. Now, the size of the cuff guys really is important because this can change readings that are inaccurate such as if the cuff size is far too small it will make our blood pressure high and that's not the accurate reading. Right? This is a false reading. Or, if the blood pressure cuff is way too big for that patient's arm, we could get a false low reading which is also inaccurate. Now if you can take a look at this chart, we see going from child to small adult to large adult all the way to the thigh, there's different circumferences of arm and different circumferences of cuff sizes. So you can see here there are markings as well, you just want to know that there are various sizes for each population and also size.