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So, when we talk hypertension, we’re talking about blood pressure that is gotten beyond the normal limits. Now, this might seem like a very simple topic to discuss but it affects millions of Americans and uses a huge amount of healthcare dollars. So, for that reason, it’s very important that we discuss and understand the implications of high blood pressure and how and what we, as nurses, can do to treat it.
So first, let’s talk really quickly about what blood pressure is. There are three main parameters you need to know. Systolic blood pressure, diastolic blood pressure, and mean arterial pressure. First, systolic blood pressure is the pressure exerted on the blood vessels when the heart contracts – or when it forces blood out into the arteries during systole. Diastolic blood pressure is the pressure within the vessels between beats, or when the heart is relaxing during diastole. So when we report a blood pressure we report it as systolic over diastolic – for example 120/80. The third metric is Mean Arterial Pressure or MAP, you’ll see this a lot when we talk about vasopressor medications or in patients with neuro disorders – it’s a calculation of the average pressure within the arterial system. So it looks at the full cardiac cycle and takes the average pressure. Now, sometimes you’ll hear us mention “pulse pressure”. What we mean by pulse pressure is the difference between systolic and diastolic – or SBP – DBP. It gives us an idea of how hard the heart is working – we use it a lot in neuro and cardiac patients.
So what are the ranges for blood pressure. Well this table is based on the 2017 American Heart Association guidelines. They’ve actually removed the term “prehypertension” and lowered the threshold for diagnosis – the hope is that people can begin receiving treatment sooner! So normal is less than 120 over less than 80. If your systolic goes above 120, you’re considered to have an elevated blood pressure, then Stage I hypertension exists once your systolic is between 130-139 and you diastolic is between 80-89. Stage 2 hypertension is >140 over >90. We see patients hitting hypertensive crisis when their systolic blood pressure is over 180 and/or their diastolic is over 120. We’re going to dive deep into hypertensive crisis in the case study that’s attached to this lesson so make sure you check that out! Now one thing that’s really important to note here is that these measurements need to be accurate. When we take blood pressures with a blood pressure cuff, it’s possible to get inaccurate readings just by having the wrong size cuff. So make sure the cuff is the right size. If we’re going to treat based on this number it needs to be correct. Details about sizing can be found in the care plan attached to this lesson.
So what causes hypertension? Well we have two kinds, primary hypertension and secondary hypertension. Primary hypertension doesn’t have one specific cause, while secondary hypertension is usually caused by some other disorder. So what does cause primary hypertension? Well there are quite a few risk factors, what we want you to see is that there are some non-modifiable risk factors and there are some modifiable risk factors. Non-modifiable means there’s nothing the patient can do to avoid the risk. Examples would be increasing age, family history of hypertension, and race – specifically african americans are at higher risk for developing hypertension. Then modifiable risk factors – this is something the patient could change, which we’ll talk about a lot with patient education – these are things like obesity, smoking – this is huge – if they smoke they need to stop smoking like TODAY, stress – that increases cortisol levels which puts stress on the heart, hyperlipidemia, coronary artery disease, and atherosclerosis – those can all cause SBP to increase because it’s pumping against hardened or blocked vessels. Then dietary things like salt intake which causes water retention or caffeine intake which causes vasoconstriction – all of those things can cause hypertension.
With secondary hypertension, the most common things that can cause it are pregnancy (you’ll see in OB we’ll talk about preeclampsia and eclampsia), renal and CV disorders which tend to exacerbate each other and make blood pressure go up, and diabetes which can do a lot of damage to blood vessels. So patients with these conditions are at risk as well.
When it comes to symptoms, the reality of hypertension is that sometimes there are NO symptoms until it starts causing end-organ damage. That’s why we call it the “Silent Killer”. Someone may not check their blood pressure regularly and have no idea they have hypertension until they have significant problems. Some of the later signs would be vision changes because of the effect on the pressure and vessels within the eye, frequent headaches and dizziness because of pressure in the brain, and even chest pain because of the strain on the heart. The biggest things we see as end-organ damage and the ways that super high blood pressure can be the most dangerous are strokes, renal failure, heart failure, and heart attacks or myocardial infarction. You may have a patient present with the worst headache of her life and blurry vision, turns out her blood pressure is 240/120 and she has had a hemorrhagic stroke! But her blood pressure didn’t suddenly go from 120/80 to 240/120 – it’s a gradual thing. So we need to stress how important it is that our patients get their blood pressure checked at LEAST annually. But they can always just go down to CVS and have it checked for free!
When it comes to medication management, the goal for hypertension is to address the blood pressure with multiple mechanisms. Most hypertension patients will be on at least two of these medications, because they all have a different mechanism of action. ACE inhibitors, those are our -prils like Captopril, and our ARB’s, that would be your -sartans like Losartan, will prevent water retention and cause vasodilation by blocking the RAAS. Beta blockers, that’s the -lols like metoprolol, will slow down the heart and decrease contractility so that pressure can decrease. Calcium channel blockers, the -pines like nicardipine, will relax smooth muscle in the vessels so they dilate, it also decreases contractility. And we give diuretics to offload the system – we want to remove some of that preload so the overall blood pressure can decrease. These are your -ides like furosemide or hydrochlorothiazide. So we give them a combination of these to help address their blood pressure and prevent end-organ damage. HOWEVER – there is SO much the patient can do to improve their hypertension that patient education is a MUST
Like we talked about with the modifiable risk factors – there’s a LOT patients can do to decrease the risk and prevent complications from hypertension. These are mostly diet and lifestyle changes! Remember what the #1 change is? Smoking Cessation! If they smoke, they’ve got to stop! That will decrease their risk exponentially in a very short period of time. We will also teach them the DASH diet – this is a low sodium diet. They need to learn how to not add salt to their foods, avoid processed and canned foods, etc. They should decrease caffeine intake and reduce stress – boy, that’s easier said than done, isn’t it!? Especially for nursing students. But it’s so important. And then, anything they can do to reduce weight will be beneficial – diet, exercise, yoga can help with that and stress reduction. The point is, its our role as the nurse to empower our patients with this information – they can make a huge difference in their own health if they’re willing to be a part of it!
We’ll cover more specific nursing interventions in the care plan, but just to recap the top 3 priority concepts are going to be perfusion, obviously, because this is a perfusion issue, and then health promotion and education are going to be key for these patients – that’s a huge part of our role as nurses and it needs to be prioritized.
So remember the normal blood pressure ranges have been shifted down recently to allow for earlier intervention, so make sure you familiarize yourself with those. Secondary hypertension is caused by other conditions, but primary hypertension is manageable and can even be prevented! When they are put on meds, many times we approach it through multiple mechanisms to have the biggest impact. Patients may not even have symptoms until it’s too late so we have to stress the importance of screening and monitoring. We are on the front lines here and we HAVE to teach them how to take care of themselves, it’s a top priority for these patients.
You guys are going to be amazing nurses are you’re going to make such an incredible impact on your patients. Go out and be your best self today! And, as always, happy nursing!