 So I think it's just working here in the microphone. I don't know if people want any notes or not, but I did make some handouts on the slides that I'm gonna be presenting. So if you want some, you can have them. And if you don't, that's fine too. I wasn't quite sure about the format for today. So I'm an aphrologist and that means that I take care of the medical problems with kidneys and how kidneys function. I don't cut out your cancer and I don't give you chemotherapy and I don't give you immunosuppressive therapy to take care of kidney cancer that's gone outside of the kidney. What I do is deal with what's ever left over essentially and my job is to keep that kidney function going. So I'm pleased to be able to talk with you today and I thought specifically what we would do is talk about what kidneys do. Oh, now it's on, okay. How you measure kidney function. And the main thing I wanna focus on is how to preserve what you have left with your kidneys after you have undergone an infrectomy. So just to get us oriented here, you normally start off with two kidneys. I'm sure you're all aware of that. And blood comes out of the aorta, big vessel from the heart, goes into the kidney through this renal artery. And when I use the word renal, all it really means is kidney and I'll use those words interchangeably. In the kidney, the blood gets filtered and it comes back out through this renal vein and then goes back, the blood goes back after it's been cleaned to the vena cava. And we're gonna talk about how the kidney cleans the blood. Meanwhile, urine is made in the kidney, pretty fascinating process, but then I'm biased as an aphrologist. It goes down this tube that we call a ureter. So the ureter is the tube that takes the urine from the kidney to the bladder and the bladder holds your urine until you wanna excrete it through a urethra. And you may not have thought about it, but a bladder is a pretty handy thing to have. Because if you didn't have a bladder, maybe some of you don't, you would just have a continual outflow of urine. And sometimes that happens when we're treating cancers and you have to get rid of the bladder. It's also pretty unique because you can drink something now at this conference, you could go get on an airplane and you could take your urine across the country and you can transport things in the bladder. So I'm very fond of that part of our system. So we're gonna talk first about what these kidneys do. And kidneys are very simply blood filters. And they're designed to remove waste products from your body. And those waste products come from several things. From the food you ate from the lunch. The big things are that our chunky will come out in your stool. The small things that you absorb through your intestine will get into the blood and then they will go to the kidneys where your kidneys will filter out what you don't need. If you're taking medications which you're gonna find is those drugs that you take, a lot of them are also filtered out through the kidney. And then another part of the waste that the kidney deals with is old body parts. You may not have thought about that but the cells that make up your body are changing and breaking down and turning over. And some of those waste products from that cell turnover is also gonna get filtered out of your body through the kidney. So the kidneys are these blood filters but they're also equipped with very specialized sensors and regulators. So they filter all the blood and we would all just shrivel up and die unless we had part of the kidney to recover what our body needs. So the kidneys will sense and regulate many things. They'll regulate the fluid in your body. If you drink a lot of fluid and your body doesn't need that fluid because you're not dehydrated, you're gonna pee it out. If on the other hand that you're dehydrated, your body's gonna try to keep that fluid in. The kidney also regulates a lot of what I call body salts and that includes a whole group of things that are just charged molecules. So we think of salt like sodium and table salt but there's other salts that the kidney regulates such as potassium and calcium and phosphate. The kidneys regulate your blood pressure. There's a special group of hormones, starts off with this one called renin and what this renin does is it helps maintain your blood pressure and in fact people who are hypertensive have high blood pressure. We actually give them medications to suppress some of these hormones so the kidney can regulate your blood pressure. Believe it or not, your kidney also regulates your red blood cells, how anemic you are. So you know you have a bone marrow and that's where the red cells come from but it turns out that it's the kidney that has the signal that goes to the bone marrow and says make more red blood cells so you're not anemic. So people who have a lot of kidney dysfunction or kidney failure will tend to be anemic because they lack this hormone. The kidney is also critical for your bones and it regulates several hormones, vitamin D, something called parathyroid hormone and again some of those salts, calcium and phosphate, to help maintain your bone health. So kidneys are filters of the blood but they have a lot of special sensors to determine what you want to keep in your body. So the question in them is how do kidneys filter? How is this actually done? So you have within the kidney microscopic filters, they're called nephrons and here I have a kidney and it's cut open and what happens is that blood comes through this renal artery, you know the artery to the kidney right off the aorta and it comes out down here into one of these filters and then magic happens and urine is made right here, the blood gets filtered and this urine is collected through a series of tubules and it goes out through the ureter and held in that bladder for you. This filter unit in the kidney is called a glomerulus. It is a blood filter and these tubes here that collect the urine and have the sensors to tell your body how much water to hang on to, how much of those salts to hang on to, those are tubules and each glomerulus comes with its own set of tubules, they go together and together they call it a nephron. So I'm called a nephrologist because these are the little things that I try to preserve. Now, you were born with about half a million, I have here 600,000 nephrons in each of your kidney. If you were to lose a kidney, we consider you a kidney donor and you can do just fine with 600,000 of those nephrons and you can actually do fine with fewer than that. The nephrons decrease with age and one of the things that I think is fascinating to show you how important this filtering activity is of the kidney is that when your heart beats, every beat, 20% of that blood that comes out of the heart goes to the kidney to be filtered. So I mean, these kidneys are these tiny things in your back and yet 20% of the blood when the heart beats goes to the kidneys to be cleaned. The nephrons will decrease if you have kidney disease. Kidney disease can affect the filter unit, it can affect these tubules, but if you don't have both together, that nephron is gone and so when we talk about kidney disease, we talk about a loss of nephrons. And again, as I mentioned, if you have a kidney out, you have an instant loss of 600,000 nephrons just like that with the surgery. So let's look at this glomerulus in a little more detail to show you how it actually filters. So now I'm just drawing that glomerulus. So we're just gonna look at this structure right here and what happens, there's two diagrams, is you have blood that comes into this part of the glomerulus and this is the unfiltered blood and I've made these little red things to represent cells and then these waste products or these smaller little dots, if you can see them, they may not be too visible. And then what happens down here is because there's holes here, which I'll show you in another slide or two, the small toxins will get filtered through and come out the urine. So the principle is very simple, small molecules, those waste products that are in our blood that you don't need, just get passed through this filter and these large molecules then go outside the filter without the little toxins in them and the blood is filtered and it goes back through your vena cava and the rest of your body. Now how much you filter in here is determined by how much pressure we put on there. So if we open up that side where the cells are coming in, really wide, you get a lot of blood there and if we wanna filter it through this part in here, what we do is we put some squeeze on the other side. So you let the blood come in and the body has some mechanisms to squeeze here to push the fluid that's in the blood through this little filter to get things out and I bring that up because that's something else we're gonna talk about when we talk about preserving kidney function. All right, so your filter blood goes out. So let's look at this filter blowing up a little higher. We're gonna take this segment right here and now what you're looking at is just one of these little blood vessels that's in the glomerulus and inside this blood vessel are red cells and toxins, these little things here and there's some protein and then we're gonna cut that capillary, that blood vessel open and if you're looking inside where those bloods are, this is what you see, it's just a filter. Like a colander that you would put some fruit in or some pasta in where you wanna catch the big stuff and the little stuff goes out. So this is the filtering process of the kidney and that's what you actually see if you're inside the glomerulus. And so the rate at which we can move these toxins through these holes is called the glomerular filtration rate, GFR and that's actually how we quantify kidney function. We quantify it by how it filters out the toxins even though the kidney does all kinds of other things saving your fluid in and regulating your salt. We talk about kidney function in terms of this filtration. And one of the things then you can see is if all of a sudden these holes get big or there's damage here, you can start to get red blood cells or these proteins in your urine and that's a sign of actually having a kidney disease not necessarily a kidney cancer but a kidney disease that's affecting those filter units. So kidney function is measured by glomerular filtration rate, GFR. And what this is, it's a volume of blood where you can completely clear out a waste as it filters through that glomerulus. And to do that, those microscopic filters have to, that's tough. It's really hard to measure this. And if you really wanna know how much kidney function you have, what we do is we inject a radioactive substance into you and we watch for the kidney to clear it through the urine and we see how much of that radioactivity comes through and how fast it comes through. And that's very difficult to do in time consuming. So instead of always measuring your glomerular filtration rate, we estimate it. And we estimate it by a molecule called creatinine. Now creatinine is a breakdown of muscle. So our muscles, as I said, like body parts are always breaking down and reforming. So muscles are breaking down and reforming. And your muscles break down and they release this substance called creatinine and it goes to the kidney and it gets filtered through. So we use creatinine as a marker, it's a small molecule of one of those waste molecules that gets filtered through the kidney. And you can measure your blood creatinine level, which is what they do, and then we have some formulas that have been derived that will give you a glomerular filtration rate. And those are based essentially on injecting people with this isotope, seeing what their actual GFR was and then finding some parameters that could come up with the same number. And so you use the creatinine and you use your age into that formula. And it's not a great formula, but it's out there and it's actually reported in your lab results. And I'll show you that in a minute. You can also, instead of measuring this and putting it in a formula, you could measure what comes out by doing a 24 hour urine collection. So a few people may have done that. It's called a creatinine clearance. It's another way of getting at this GFR or glomerular filtration rate. So when your kidneys quit working, say you can't get any creatinine in there out, what you find is the creatinine in the blood goes up and you get less creatinine in the urine. Creatinine is merely a marker of these waste products that the kidney filters out. There are hundreds of them, but we don't measure them all. For convention, we just use creatinine. And there's a lots of controversies whether that's the best marker to use, but that's what we're doing right now. So if you wanna know what your kidney function is, you go ahead and you get some labs. And here's just labs from our university and what you find here is this number called creatinine. In this example, it's 2.76. These are the normal reference values. So the creatinine's up, the kidney's not filtering it out. And what happens if you go and take that number and you plug it into one of these formulas, you'll have this value of GFR, glomerular filtration rate. And that's actually in your lab reports. And you notice that they give you two values and you have a choice of being non-black or black. Now this is sort of bizarre, but this comes to how we got these formulas derived. And it was based on an American population where they're either Caucasian or African descent. So these formulas may not apply to you, especially if you're not of that racial group, but that's what's out there, that's what's reported. And you gotta kinda keep in mind that it is a derived value, so not to get too alarmed by that. So the question is, why would we ever want to plug it into a formula so that it doesn't really necessarily always fit? And this is why. And that's because physicians didn't pay attention to glomerular filtration rate. Let me give you an example. If you have a creatinine in your blood of 0.8, what you notice, here's your GFR by one of those formulas, if you're a white male. And you can see, first of all, that your GFR goes down with age. But if I have a change in creatinine of just what, from 0.8 to 0.1, so that's a change of 0.3, look how much kidney function you lose in your GFR. You go down quite a bit. And so the nephrology world decided to publish GFRs to have people recognize that a small change in creatinine can be a big loss of GFR. Creatinine goes up a little further. And if I go from a creatinine of 0.8 to 1.5, you have lost half of your kidney function. That's like you just had a kidney taken out. So this is out there in your labs when you're looking at it. And I just wanted to make you aware of it and why it's out there. Because quite frankly, sometimes it's not the most reliable assessment of your kidney function. All right, and other numbers and you lose more GFR. So up here is normal and anything down here is less than normal. So the nephrology world did something different in addition to this. They decided that they were gonna stage what kind of kidney disease you had. And they were gonna stage it based on this glomerular filtration rate. So if you have the filtration through that glomerulus of a hundred, you have normal kidney function. And if you have no creatinine, no filtration through the kidney, your glomerular filtration rate is zero. And that means that your kidneys are essentially in stage and you're needing some sort of renal replacement, a transplant, a dialysis. So what happened is they have these stages of kidney disease and sometimes you will find these in your labs. And I don't want you to be confused because it says something about your GFR but it may not say that you really have a kidney disease. And the stages of kidney disease are based on this GFR. And what you can see is the higher number, the lower your GFR. So if you have a stage five kidney disease, your GFR, E stands for estimated is less than 15 and these are the people that are gonna be needing renal replacement. And as a nephrologist, we only really worry about how the kidneys can get rid of their toxins and their waste when you get down to the stage four or five. But sometimes in your lab reports, depending where your labs are, they will say that you have stage four kidney disease. When you get a GFR that's less than 20, we actually think about transplants. So this will stage your kidney disease from any kind of cause of kidney failure. And here's the common causes of kidney failure. Diabetes and hypertension being number one and two. On here, you'll notice there's nothing about renal cell carcinoma. Renal cell carcinoma does not necessarily make you lose. It's not a disease of this filter. Your filters work fine outside of your tumor. So we go back to this staging system and let's talk about how much kidney function you have on this stage of chronic kidney disease when you lose a kidney. You start off, you got two good kidneys, no kidney disease, your GFR is 100. But if you have an effect to me and you lose one kidney, your GFR is 50. So if you're looking at a lab report, they may say you have stage three chronic kidney disease because the lab doesn't know that you just had a kidney removed. Doesn't mean you have a disease. It means that you just had a kidney removed. And if you lose one kidney and a bit, say you lose a half of another one, your GFR is about 25 mils per minute. And that just is where we start worrying about how the kidney is clearing toxins where you need to say watch your diet and be particularly cautious with the kidney function that you have left. So there's a lot out there. You're a very special group that was not necessarily designed for reading this estimated GFR and interpreting in terms of kidney disease. You're just people who lost some nephrons because you had a cancer and you had to get rid of them. And the nephrons you have left may be perfectly fine and you may not have any other problems as long as you don't get another kind of kidney disease. So how do you know if you have a kidney disease other than a cancer? Well, it turns out that when you have a kidney removed, there's normal or there's non-tumor tissue that comes out with it. So here's an example. This is an infrectomy that was done. And here's the tumor. And look at all of this. That's normal kidney tissue. Here's another nephrectomy. We put some ink around it so you can see the margins of it. This person also had a little weight loss. This is all fat in the yellow. And then here's the tumor. This is a transitional cell carcinoma. But look at all of that kidney that comes out with it. And you couldn't save this because otherwise you couldn't get rid of the kidney. So what we do is we have the pathologist examine another microscope. So at the time of the nephrectomy, they could tell you whether or not you had any other kind of kidney disease. And generally we can also do that by your history and just looking at your labs ahead of time. So how do you preserve kidney function? If you've got some sort of kidney disease other than the cancer, then you probably need to see one of those nephrologists. Somebody who's gonna worry about your filter unit such as myself. And then there's this other thing that we consider and it's called renal hygiene. There's some things that are good for all kidneys whether you have one or two. But particularly if you have one. The main thing is you wanna keep your blood pressure controlled. That filter unit, remember the blood's coming in through that filter. If you have a lot of pressure coming in there, you're gonna blow apart those nephrons that you have. So we try to keep your blood pressure down. Usually under 140 over 90. We try to avoid other toxins to the kidneys. There's a lot of controversy about these anti-inflammatory drugs, non-steroidal anti-inflammatory drugs. That's what this NSAID is. Ibuprofen, naprasin, those drugs. We try to avoid them. But you know if you've got arthritis and you need a couple, probably isn't gonna hurt as long as the rest of your kidney function is normal. You're gonna, if you have renal cell carcinoma probably be scanned with some contrasts and CTs and things coming up. You can have contrast if your kidney's normal but you know it'd be nice not to have a contrast study every week if we can help it because that contrast can be damaging to the kidney and the filter. A low sodium diet's a good thing. It turns out if you drink a lot of sodium you're gonna drink a lot of water and it puts a lot more pressure through that filter unit. And then there's an interesting concept. There's some medications that are useful that actually go and work on those hormones that control blood pressure. But these hormones also control the filtration. So remember when I said you had two kidneys and every time the heart beats 20% of that blood goes to your kidneys. So if you have one kidney, every time the heart beats 20% of that blood flow goes to that one kidney. Or if you have less than one kidney all the blood flow goes to that. And so what happens is that this where the blood's coming in you get a lot more blood flow coming in. And what will happen is where this filtration occurs where these toxins goes through these cells around there will essentially get pulled apart. And then you'll get a lot more filtration in urine made here and the cells lining this glomerulus will pull apart. And then what the body does is it goes and it puts in a scar here. So that what you wanna do is try to prevent so much filtration. So what do we do? We take these drugs, they're called prills like an allopril, isinopril, benazepril, quinopril, you might be on them. Or other drugs called sartans, lo-sartan, candisartan, those kind of things. Those drugs go up here to this part of the blood vessel that takes the blood out of the filter. And what it does is it opens it up and it relaxes it. So if you've got 20% of that heart cardiac output going into that kidney you can get it out faster and try to prevent this hyper filtration which can damage the remaining nephrons that you have. How much water do you need? People talk about water, eight glasses a day or whatever you need. Well the amount of water that you need really depends on how thirsty you are. So that if you eat a lot of salt it's gonna trigger thirst. Your body wants the salt in your body at a certain concentration. So it causes you to drink more water. And how this works is there's actually a hormone in the brain and the hormone is something that's called anti-diuretic hormone, ADH vasopressin. And so if you drink or consume a salty meal, Chinese food, whatever, and all of a sudden you're craving for thirst that hormone that's made in the brain because your sodium concentration got too high goes to the kidney and it tells the kidney to resort more water and dilute out that sodium. So it triggers you also to dilute it out and it drives your thirst. So when you say that you're thirsty it really means that the concentration of sodium is up. And this is what happens when you were to go out in a pub, beer is essentially pure water. So they wanna give you something salty so that you will eat the salty things. It will trigger your thirst and you'll drink more beer. So this is a good trick. Peanuts are really pretty cheap if you can then sell them more beer. So you get back to how much water a day that you really need to drink. And I can tell you that if you have normal kidney function it's not so much water you need to drink. The kidney can get rid of all those waste if you make this much urine a day. All you have to do is make 500 seizes of urine to remove your body waste because the kidney is smart and it can concentrate that urine and hang on to the good things and the fluid it needs that will recover that. If you drink more then you're gonna obviously urinate more but you don't have to force water. It's good, have a liter a day or so but you don't have to think that you're gonna help your kidneys by drinking eight glasses of water a day. All you'll do is just pee more. I've talked a bit about how we assess kidney function and I've tried to clarify some things so if you're looking at your lab slips you don't get scared thinking you got a stage three kidney disease when what you have is just one kidney that's functioning normally. Kidneys filter your blood, they remove the toxins, they'll adjust the fluid, just all the salt. This filtration is actually measured by creatinine but we translate it with an equation of formula into glomerular filtration rate. If you lose one kidney your glomerular filtration rate becomes 50% and we just consider you a kidney donor. People live fine with one kidney. You can probably get by on about 25% normal kidney function. I see people have one kidney out and then they get another renal cell carcinoma and a little bit of this kidney part comes out but you get down to 25% you might need to see a nephrologist after that and clearly you wanna do those renal hygiene. You want to control your blood pressure, avoid some of the high salt, the toxins and then to prevent that hyper filtration you take medications that lets the blood out of the nephrons faster. And if you have any questions this is how you reach me and my pager's actually on 24-7 and email is fine and I wanna thank you for your attention and for helping protect the smartest organ of the body, the kidney, but not that I'm biased. Just a moment so we can write it down. Tell you what, let me put it up here. There you go. When you were talking about water I got a little bit confused. If one drinks a lot of water does that put more pressure on the parts that you were saying that could get blown apart? It's salt and water that does that and water so water by itself won't. Water if you drink too much you can actually become intoxicated with water and it can cause other problems for the kidney. So you just don't wanna keep forcing it. Drink because you're thirsty and then stop at that point. You talked about the creatinine and it's a measurement of the muscle. It comes from muscle. Okay. What if somebody works out sternum and flea? Excellent question. Jim. Yep. You're tearing down muscle. Yep. Hopefully rebuilding the background. And their creatinines are higher. And so they run higher, exactly. And so when you put it into their GFR equation that's another reason that that formula doesn't work. So professional athletes, yep they're gonna run higher. They're gonna look like they have one kidney based on their creatinine and their GFR. Thank you. Excellent. Well I would hate to give up mine. That's not a, you know everything in moderation. So but it doesn't hurt that if you drink tea or coffee and there's some diuretic effects you're going to end up say losing more fluids that way but it doesn't necessarily hurt the kidney in any way. Yep. No I consider that since I work on the transplant side two people with one kidney are kidney donors and their kidney function that's left is excellent as long as they don't have another kidney disease. The problem is when you donate a kidney nobody except me who does some research in kidneys probably wants it. How do you know if you have hyper filtration? What happens first is you will start to see some of that protein leak through the filter. So in other words those big molecules aren't supposed to get out of the filter and that's one of the things that nephrologists will do is they start looking for a little protein and that says that there's probably a problem in those nephrons that are left over. I mentioned was contrast and I asked a question about it earlier and you were the one to really ask. I'm running on one kidney and I'm getting scans quite often because I'm being closely observed. So how worried should I be about having contrast or CT scans every three months? If your kidney function is left and you don't have other kidney disease I wouldn't worry too much. To help you go into these studies you just don't wanna be dehydrated. That's the main thing. So if you can have yourself tanked up with some extra both salt and water that's good if they want you not to have anything to drink for whatever reason for the study then it doesn't hurt if they give you a little bit of saline IV ahead of time. But if your kidney that's left is normal you should handle it okay. You described it as blood being pushed through a strainer. It's gotta be more than that right? So actually we don't think it is. It's the idea that you have a lot of pressure that comes through a filter and the filter can only expand so much. Think of a balloon and when all of a sudden that balloon has enough strain it pops. So what happens is there's cells in that filter unit and that nephron that keep it together and when that pressure gets high enough the cells pull apart and it starts a scarring process and that nephron then shuts down. So it really is the filtration through there and just the amount that's going through. Epithelial cells. This is, yes, I had two partial nephrectomies a little over a year ago. So one of the things you wanna know first of all is if there was any kidney disease separate from the cancers which they should be able to tell and if not then it might be that you're beginning to do that hyperfiltration and if you see some protein in there you might wanna talk to your doctor about some medications or see a nephrologist. Extremely low blood pressure where they are concerned about it. That's a tough one. Sometimes what we do is sneak a little bit of the medication in when you're sleeping at night. So you don't have to get up and lower your blood pressure and fall down. And there are some of those medications that lower blood pressure but you know they're not so good at lowering blood pressure but they can still help the hyperfiltration things. Oh, they can. Yeah, so we use the ones that are least effective for blood pressure in that case. Any advice for kidney stones? Oh, kidney stones are always a problem. Kidney stones can recur. We think there's something that is in your kidney that's not handling the salts well. To try to prevent them, those are the people that really need that eight glasses of water a day to dilute things out. That's one of those rare exceptions. And you actually can do a urine for 24 hours, measure the salt in your urine and then we intervene on those to see how we can prevent them from going through the kidney. But it can be a tough problem. I think that hurts or at least it depends on your doctor. Some of your urologists are gonna be good but you really want somebody just to think about do you have any other problems we need to address? And some of the internal medicine doctors are fine to do that. And sometimes what it is I've found is that you just have to ask the question and make them start thinking. I think more when my patients come to see me and they ask questions and I gotta come up with some answers. There were questions? No panel at the end. So any last nephrology questions? Yes. Sorry, do I get two questions? If someone were taking a blood pressure lowering medication in this case and a load of genes, I have understood that there is another blood pressure medication lowering blood pressure that is more kind to the kidneys. Do you know what that would be and why would it be more kind? So it's, there are medications that will help prevent that hyperfiltration and nalaparils, lysineaparils, losartans, those kind of things. So those kind of give you a double protection. They can lower your blood pressure and actually protect your kidney. And the main thing is they may not lower your blood pressure sufficiently to give you protection. Some people may need more than one blood pressure medication. Sure. Yes. Excellent question. Depends how old you are. If you are younger, that kidney will expand and grow as you get a little bit of hyperfiltration. Enough hyperfiltration that the kidney function is still good. If you're old, my age, older, that kidney's not gonna grow a whole lot. You're probably gonna get stuck with where it is. But you will actually find that sometimes your kidney function improves as it grows a little bit. They keep going. Question, but because the person over there asked twice, I just wanted to share that my oncologist gives me IV hydration before a CAT scan and after a CAT scan. And I used to get super sick every time I had a CAT scan until he did that. And that seemed to minimize the damage to the kidney. Yep.