Structural and Functional Changes of the Renal System (Nursing)

00:00 Hello. Welcome to our geriatric nursing series. In this series, we're looking at age-related changes in health. Now, we're going to focus in this portion on renal systems, but I want to start with a story first. Now remember Jose? He is our example of someone who is aging successfully. This is Jessica, his granddaughter. Now she went with him for an annual check-up not because he needed someone to go with him, but they were going to go to lunch afterwards. So, while she was there waiting for her granddad to get his annual check-up, she ran into one of her friends, Marie. She was so relieved to see her friend Marie because she wanted to ask her kind of a personal question about her grandfather, Jose. See she was starting to worry that Jose was sick. She told Marie "I heard him get up 3 times last night to use the bathroom." She just is convinced that her granddad is sick.

00:57 Marie smiles at her friend and says "No problem. Let me go in and finish the assessment on your granddad and I'll come back and talk to you afterwards with his permission." So, Marie went in, spent time with the grandfather. She explained to him that the granddaughter was really concerned about him and got his permission to talk with her about what's going on. So, after the check-up Marie tells her, the nurse, tells Jessica, the granddaughter "Hey, everything is fine. When someone ages and as they age it's normal for them to have to get up during the night multiple times to go to the bathroom.

01:36 Now Jessica was both relieved and still a little hesitant but she really trusted Marie's opinion so she left with her grandfather, Jose, but on their way out Jose sees his old friend, Enrique. Now, he saw Enrique, he said hello, Enrique had overheard them talking about what Jessica was concerned about, how many times during the night Jose was going to the bathroom and this was Enrique's response "Huh, hey those are ricky numbers. I wake up up 6 times every night and that's actually why I'm here." Jessica was kind of taken aback.

02:09 I mean, she was surprised. She thought to herself "Whoah, what is wrong with my granddad's friend, Enrique and what's the difference between my granddad and him?" Well, that's what we're here to talk about today. See, it is normal for an elderly person to have to get up during the middle of the night to use the restroom. That's nocturia.

02:32 But what Enrique is experiencing is nocturnal polyuria. So remember the term poly means multiple. So he is getting up more than the normal number of times that you would expect in normal aging without chronic illness. Now, Jose has led an active and fit healthy lifestyle.

02:54 Enrique has made different choices. He hasn't been as active. His diet hasn't been as on point or healthy. He had a heart attack at age 52. He has osteoporosis. So even though they're the same age, they've had very different health journeys. So I want you to use Jose as an example of what happens in normal aging. Enrique is our example of what happens with chronic illness on top of normal aging. So, fluid balance in older adults is a critically important issue. You know everyone's aware that you want to be very careful with our neonates and our little babies because they can get dehydrated easier and then we can really fluid overload them if we are giving them IV solutions. Well, the same thing applies as people age. Older adults have difficulty with maintaining fluid balance if it's outside of the norm. So, if an older person is sick and they're vomiting a lot or they have large diarrhea episodes, they're going to be more at risk for dehydration than in average age or a 30-year-old or a 20-year-old. So keep that in mind. If it's normal baseline conditions, older adults can maintain a fluid balance. But they have an increased risk of being overloaded or incredibly dehydrated when things are a bit extreme. So let's talk about the normal aging of the renal system. I love this picture of the young kidney and then the older grandpa kidney there. Just to kind of get you in the mood to recognize where we're moving and what we're talking about today. So, think of it, here's your framework. We're going to look at 3 areas; structure, function, and regulatory hormones.

04:43 So, before we get started I want you to think about that. Set your mind on. I'm looking at what the normal aging process is of the renal system of our kidneys and we're going to look at 3 main areas. Now, we're going to number them for you as we go through it to kind of help your brain encode that information and put it in in a way that makes sense.

05:03 So, structural, functional, and regulatory hormones. Now, what I want you to do is look away from the screen, look away from your notes, and see how many of those 3 items you can recall. Hey, if you got all 3 you're a rockstar. If you got 1 or 2, good work.

05:23 Remember, learning science tells us the actual effort you put in to recalling things from your brain. Not rereading your notes are going to really help you super charge your studying so you remember that information and can put it together with other concepts.

05:39 So there you have it. Right there here is our friend, Jose. We're going to kind of look at structural and functional together. So we've got 1, 2, and 3 when we're talking about structural and functional changes in the kidneys. So it's part of normal aging. There is our friend, Jose. Remember he's the healthy fit guy who's made really good choices and he had good genetics. We're going to look at decline in the mass of his kidney, loss of functional glomeruli and reduction in blood flow to the kidneys. Now remember this is the normal aging process. These 3 items that you see on this summary or framework slide right now are normal changes that the elderly will experience. Now let's dig in a little deeper. So, let's talk about number 1, the first change, normal change is a decline in mass of kidneys. Now we put a picture up here for you to kind of give you a frame of reference of where we are. Look, it's a little tiny baby, you've got 50 grams. Okay then as an adult, you're up to about age 40, you're at 400 grams. Now as you age, we're looking at age 90.

06:49 Look how much you've lost in grams of kidney mass. Okay, so do that math in your head.

06:55 That's one math problem that's easy to do. Right? So, it's decreased significantly by age 90. Now, usually your renal mass that's primarily lost is cortical. So, it's not as much from the medulla as it is from the cortical mass or the cortex. Second, we have loss of functional glomeruli. Now, look in the middle there. That's a great graphic for you to see.

07:22 Oh, that's the glomerulus which is that tangle of capillaries. Right? In Bowman's capsule and then it goes through the tubules. Men, that's a really important working unit of the kidneys when it comes to, that's where all the blood goes through and starts to filter there. Now, when I'm under age 40 I have maybe about 5% of those are kind of sclerotic.

07:44 So, they're kind of stiff, they're not functioning well, they're not as efficient. But by the time of age 80, the incidence increases so much, that sclerosis can involve a much larger portion of the glomeruli. Okay, so the first one, can you remember it was the first topic we talked about in normal aging. Loss of mass. Right. So we had the baby, the adult, and then the elderly adult and you lose significant mass by the time you're age 90.

08:15 Second one is loss of functional glomeruli and tubules. So, under age 40 you've got 95% of your glomeruli are good to go. But by 80 look at that number. It's significantly increased by that point in their life and it's considered a normal change with aging. Now, are you ready for number 3? Can you remember what it was? No problem if you can't. Remember, just the act of trying to remember is what's helping you study. But it was reduction in blood flow. Okay, so we're starting to put these pieces together. We've got less kidney available. The kidney that we do have available, you've got the glomeruli as you age.

08:58 You have less of those that are functioning as efficiently as when you're a young person.

09:03 Now, we're talking about less blood flow making it through the kidney. Now, reduction in renal blood flow. As you were looking for really good numbers or about 600 ml/minute.

09:15 Now, when I'm under age 40, that will start to decline by about 10% per decade. So, between 40 and 50 it's 10% less, 50 and 60 and so on and so on. Now by the time you reach the age of 80, the decrease in that renal blood flow is really profound and we've got the numbers up there for you. I want you to take a look at those and pause just for a minute and think about this. So, even in Jose who's made great choices, has good genetics, what are the 3 areas that he is going to experience changes in structure and function of his kidneys. Remember, don't look at your notes to see if you can pause and recall it.