Transcript: Microalbuminuria Case Study: Lab Interpretation for New Grad NPs

​Liz Rohr:

So urine microalbumins, you need to order them every year for diabetes and it's a quality measure. So it's important to know how to interpret them and what to do with them, and that can be a little bit tricky sometimes. So that's what we're talking about today. If you're new here, I'm Liz Rohr from Real World NP, and you're watching NP Practice Made Simple, the weekly videos to help save you time, frustration and help you learn faster, so you can take the best care of your patients.

So in this video using a case study, I'm going to be going over when to order it, when to order urine microalbumin, how to interpret it and then their next steps kind of going forward. An important note though, is I also have the Lab Interpretation Crash Course for New Nurse Practitioners opening this Friday, January 24th. Enrollment is open until the 30th and then the course starts on January 31st. It's the last time until the summer, so definitely hop in there, if you're interested in learning more about CBCs, BMPs, LFTs, urinalysis, TSH and cholesterol, very comprehensive, main stuff in primary care. So, if you're interested in that head over to realworldnp.com/labs. Without further ado though, I'm going to share my screen with you.

So let's get into the microalbumin case study. So this is Raul, he's 58 years old. He's here for a followup diabetes, and this is not his real name or his photo. There's a lack of diverse stock photography, unfortunately. So this doesn't really look like him, but he was on his phone, and so that was kind of amusing to me to choose that one. So he hadn't been seen in about 18 months and was asking for refills over the phone a month prior, and I had advised him that he needed to come in. I gAve him a month's worth of medications, and then I have him come in for a follow-up because I never met him before at my new clinic.

So he was asymptomatic at the time. He was actually kind of irritated that I asked him to come in, but safe care. So A1C, we have a point of care test. And so it was at 10.8. He's taking Humalog Mix. It's lispro protamine and lispro insulin, and so that's a combination of intermediate and the rapid acting. He's taking 30 units a day, but previously he had been prescribed twice a day, 30 units, and he also had been prescribed a couple of other medications that he wasn't taking, metformin, a 1000 milligrams twice a day, lisinopril, five milligrams daily, and simvastatin 10 milligrams.

So he has a past medical history of hypertension, diabetes, obesity, and hyperlipidemia. He has no past surgical history. He has a family history of diabetes. Luckily he doesn't smoke. He doesn't drink alcohol or use drugs, and his vitals are relatively stable at this visit. So 135/81 blood pressure, heart rate of 67 oxygen normal. His BMI was 45 though. And he had a normal physical exam, heart, lungs, extremities in general. And a couple of things I wanted to add is that he, right off the bat, kind of was a little bit defensive about, "You know what? I feel fine. I previously have lost 40 pounds. I exercise five days a week. I eat pretty well," that kind of stuff, even when his A1C was that high.

So a little not that interested in hearing it, but plan for today, I'm going to be focusing on microalbumin and I'm going to touch on the other components of care. So the labs I checked that day were a CBC, a CMP, lipids and a urine microalbumin. So results, overall the basic metabolic panel, the LFTs and the CVC were normal. The glucose was 263. His lipids were elevated. I'm going to be making a video about cholesterol interpretation for a future video, so I won't jump into that, but his lipids were high. And urine microalbumin, so the way that a urine microalbumin is reported and you've probably seen this, is you're going to get the result of the creatine, the microalbumin and then the ratio of the two.

So creatinine and microalbumin by themselves, 77.3, 96.8, those were okay. Important note though, is if you're looking at your own results, just be mindful that the milligrams per deciliter and the milligrams per liter are different units of measurement. So sometimes that kind of throws people off. However, the moral of the story is that you're really looking at the microalbumin to creatinine ratio and for his ... His was 125 and there are three different kinds of categories, and I'll jump more into this in the next slide, but normally it's supposed to be less than 30.

Microalbuminuria is considered to be anything above 30 299, and then anything above 300 is considered a macroalbuminuria or clinical microalbuminuria, so it just needs a large amount of protein over 300. So what's the point of doing this? So urine microalbumin is to assess the patient's renal status. So just kind of backing up for a second. Your kidneys really shouldn't have protein, letting protein get into the urine. And if there's protein in there, there's typically signs of damage. So an acceptable amount of protein, of albumin specifically in a day is less than 30 milligrams for the entire day. So more of that points to signs of renal impairment.

So this test in particular measures the ratio of excreted creatinine to excreted albumin. So the gold standard for measuring how much protein your urine has is a 24 hour urine test, where they just collect their 24 hours worth of urine and they submit it to the lab, and then they test it, and they quantify it. That's not that feasible. So one of the tests that you have instead is a spot test. This is one of the spot tests, there's a couple, but what it's measuring is looking at a snapshot in time of your creatine and a snapshot in time of what your albumin is, and kind of extrapolating that to what that total daily amount would be based on the ratio of those two things.

We'll get into this more in the Lab Interpretation Crash Course, if you're interested in kind of joining us for that, but basically creatine is, our body makes creatinine, or creatine exerted is creatinine, and there's a relatively constant amount during the day. It doesn't really vary day to day, and it also is not reabsorbed by your kidneys. And so that's why we use it as a measure to assess renal function.

So, when you would expect a certain of creatinine to be in your urine at a certain point, so that's why you can kind of extrapolate it to the total course of the entire day, about approximately. There's some caveats to think about, but anyway, it's a spot test. Then the albumin again, you're looking at the amount of albumin at that time, comparing to the amount of creatinine that's in there, and then you can kind of extrapolate both of those to the total amount of an entire day, and it should be less than 30, and it's not in this patient's case.

So a couple of notes about just terminology. So, "microalbumin," I think, is misleading for some people in terms of being a small ... It's actually a small amount of protein, not like tiny particles of protein, which I don't love that name, which is probably why it's actually been updated, that it's moderately increased albuminuria, it's the new acceptable term. And macroalbuminuria, macroalbumin again is not large amounts, not large sizes of albumin or large sizes of protein, it's a large amount of protein, and that actually, it's called severely increased albuminuria.

So the main differentiating point here is that when you do a urine dipstick and I'll show you this on the next slide, but when you have a urine dipstick, it becomes positive when it's macroalbumin. So little amounts, those tiny amounts of that microalbumin is slightly above normal, is not detected by a urine dipstick. So that's why we have the separate test. So this is what it looks like visually. So when you have your urine dipstick, you have trace amounts, 1+, 2+, 3+ and 4+ that correlates with higher and higher amounts of protein in their urine, and 4+ is really concerning. Just so you know, when going back to that first slide that I mentioned, the range is greater than 300, there's less than 30, 30 to 299, and then greater than 300. Greater than 300 is that macroalbuminuria which is detectable by dipstick.

So if you're looking for protein, that's not detectable on dipstick, that's like an early sign of renal impairment, again, microalbuminuria. The normal amount is less than 30, if you're looking for those early signs of renal damage, you're going to look for smaller amounts. So this is reported, this is in the range of 30 to 300 or 30 to 299. And so, one other important note I want to make is that you have two options for assessing this. You can send it out to the lab and they'll give you an actual number, like you got for the patient in this example, where it was 125. Or if you have the option, I don't have this, but if you have an option on your urine dipstick, the result may come back as "30 to 300," meaning that it could be 125, it could be 299, but the urine dipstick machine can only determine that it's in that abnormal range, if that makes sense, so instead of 45, but if you want to get an actual number, then you can send it to the lab.

So why are we doing this? I've kind of said it a couple of times, we're looking for signs of renal impairment. It's an annual screening test for diabetes, it's a quality measure. So, if you have increased small amounts of protein, microalbuminuria, it increases your risk for it progressing to that macroalbuminuria, that high amounts of protein that's visible on dipstick, and the higher protein that you have in your urine, the worst prognosis that you have in terms of your renal impairment. Patients who have elevated microalbumins also have increased cardiovascular risk, and they also have increased long-term mortality. So you'll see some people doing this in patients who have elevated high blood pressure and hypertension. There's not enough evidence to make it into a guideline in terms of, "We should test for it and give this treatment, and this treatment is effective," but you'll definitely see people doing that. There's some evidence.

So how are we doing this? Just again, it's a spot urine test. So you just do a random urine test during the day. There's not necessarily an ideal time. This actually was practice changing for me, because I thought it was a one-time reading, and then I realized that it actually can be transiently elevated. So it's actually recommended to repeat about two times, two to three times over the course of a three to six month period. So it can be transient with exercise and fever.

So a couple of caveats to think about for this test. I get into this more again in the Lab Interpretation Crash Course, but in terms of measuring creatinine, it's a constant amount, but if you're a bodybuilder and you have way more muscle mass than somebody who has cachectic body habitus, and so, the creatinine amount that's excreted during the day is going to be different because it comes from muscle, and also it doesn't really account for gender and race differences. And then the other thing to think about is that microalbumin is a specific screening test for diabetes.

I know if you're a new grad NP, if you're anything like me, you like to have these kinds of one, two, three, four algorithms where things are very clear. And yes, it is a test to screen for early signs of kidney impairment and diabetes. However, you always have to keep that healthy skepticism in the back of your mind, knowing that this is just a test to show for renal impairment, and there are other reasons why you can have that. That's not specific to diabetes, right? So likely if somebody has diabetes and hypertension it's probably from them. That's most of the time in primary care, when you see renal impairment, it's because of those kind of chronic conditions.

However, you always want to look for ... And that's another reason, an important reason to repeat it in the next three to six months, you want to look at other causes. So if there's a rapid increase in the amount of protein, so if it was 125 today, and then it was like 4,000 or something, it probably wouldn't be that high. That would be ... Anyway, it wouldn't be that high, but if it went from 125 to 500, that would be a significant increase. If their GFR had dropped, if they had resistant or unresponsive hypertension, like it was just really high and it wasn't responding to any medications, those are all signs of something else going wrong with the kidney.

Then if they had other things in their urine sediment. So if you did a urinalysis on these patients and it showed other signs of renal impairment, again we talk about this in the Lab Interpretation Crash Course. You can get so much data from a urinalysis, but if they had blood, white blood cells, casts, things like that, again, that would point you in the direction of something wrong with the kidneys, and then symptoms of other diseases, right. So if somebody also has lupus, you want to think about, is lupus going to be contributing, other kinds of diseases that can contribute to that.

So what do we do? So you have a high amount, so what are you going to do to treat them? You're going to treat the underlying cause. So that comes to, in most of the time, diabetes, hypertension, et cetera, et cetera. And diabetes, this is practice-changing for me as well, because I had initially thought that anybody with microalbumin elevations, a small amount of microalbumin in a urine should be on an ace-inhibitor, and really the evidence points to only patients who have hypertension and diabetes, to prevent progression. There's less evidence for patients in diabetes without hypertension. You'll definitely see that, people prescribing that, but again, the data doesn't necessarily support it in terms of the research studies.

Then another side note, there's a small amount of evidence that verapamil and diltiazem, those particular calcium channel blockers can help prevent progression of the protein. So if you are thinking about a secondary agent in somebody with diabetes and hypertension, thinking about if those are applicable to them, would be helpful. And then you want to, whenever you start in ace-inhibitor, you want to check the BUN, creatinine and GFR about three weeks afterwards, to make sure that there's not a more than a 30% increase in the creatinine, which can point to some other renal things going on. Then the other thing to think about is just lipid control, right, because they have an increased cardiovascular morbidity when it comes to microalbuminuria. So you want to think about what is their cholesterol and do they need any treatment for that.

So four steps, this is just kind of a recap here. So number one is it transient, right? So more than likely this gentleman is not, because he has an A1C persistently elevated over time, but anyway, we're going to repeat it. Are there other signs of renal disease going on, just to make sure that we're not just assuming that it's diabetes, right? BUN, creatinine, GFR. Do they have unresponsive hypertension? Do they have anything weird looking on their urinalysis? Number three, you want to control the cause the diabetes, the hypertension, and then consider adding an ace-inhibitor, if that's appropriate.

So what's next? We're going back to Raul. So we can proceed with management for him, likely this is related to his diabetes and hypertension. You want to advise him on diabetes and hypertension control with medications. And then the next visit when he comes back in about three months, rechecking the microalbumin, considering rechecking a BUN, creatinine and GFR, just to make sure that there wasn't something progressive underlying that we were missing, right. Considering also doing a urinalysis, like a dip in the office to look at that for other signs of renal impairment, and then restart taking the ace-inhibitor.

So his blood pressure actually is only borderline high. It's 135/81, and the new guidelines, depending on which guidelines you're looking at, some of them are recommending under 130/80. So you could consider restarting it for him. And then for further management, I recommended restarting a previous dose for his insulin, because before it had worked and his A1C was lower, and he also knows how to check his blood sugars. He knows the signs of hypo and hyperglycemia, as well as the metformin. Then again, consider restarting lisinopril, repeating it at the next appointment and then lipid control. And actually, I wrote atorvastatin 20, he actually would qualify for 40 or 80 because of his risk factors of diabetes, hypertension, things like that.

So again, just final recap. So we called with the results over the phone, and kind of further talked about what that means. I advised him to come back in a month to talk about diabetes. He was not interested. In our clinic, if anyone has an A1C over nine, we do monthly visits, even if we're not rechecking the A1C, just to make sure we're on the same page about medications, blood sugar monitoring, things like that, but he said he would come back in three months. So it's kind of a harm reduction strategy. As long as he comes back, I'm all right with that. He said, he's going to restart checking his blood sugars and he's due for a physical exam. So I could theoretically do a physical exam the next time he came in.

However, I'm a little bit worried about losing this patient to follow up, because he was not very interested in being at this visit and he was a little bit irritable about it. But I think hearing about the microalbumin was a little bit concerning for him. So he's a little bit more motivated, but we'll plan on doing a physical the next time, because I really want to focus on the diabetes first.

Did you like this video? If so, hit like and subscribe and share with your NP friends, so together we can reach as many new nurse practitioners as possible, to help make their first years of practice a little bit easier. And if you're interested in the Lab Interpretation Crash Course for New Nurse Practitioners, just letting you know, so you don't miss out this time. It's January 24th is when it opens. I definitely recommend earlier registration, and class starts on January 31st and it goes for four weeks and that's the last time it's coming before the summertime.

So, definitely come on over and join us at realworldnp.com/labs. And if you haven't gotten your copy of the Ultimate Resource Guide for the New NP yet, go over to realworldnp.com, sign up for that. You'll get it sent straight to your inbox with these videos every week, sent to your inbox as well, patient stories, more insights and bonus content that I really just don't share anywhere else. Thank you so much again for watching, hang in there and I'll see you soon.