ACE Dosage Calculations in 6 EASY Steps | Dosage Calculations Practice Problems

In this video I am giving you the easy six step process for acing dosage calculation problems every time in nursing school. We've talked a lot here on this channel about how to ace your nursing school classes and now we are going to ace Dose Calc together. Don't miss out on the end of the video because I am going to give you the must know tips that you need to follow or you will really struggle on your dose Calc exam. Now click that subscribe button and hit the notification bell and let's dive in. So here's how this video is going to go. I'm going to walk you through the easy six step process here. Then we're going to apply it and use some real life dosage calculation problems and examples. I'm going to go through several examples to really help it sink in for you. So here's our first practice problem and I'm going to explain the steps as we go along. Now your patient Mary has been hospitalized for four days for bacterial pneumonia. She is prescribed 250 milligrams of levofloxacin to be taken orally once per day for the next 14 days until her next appointment. You are getting ready to pass her meds this morning, but you only have 500 milligram tablets in your med card. Now Mary is going to be discharged this afternoon. How many milligrams total will Mary need to go home with? So the first step is to figure out what you need. You need to decide what the question is actually asking you for. Now this is step number one because you need to find out what you need to end up with at the end so that you know what conversion factors to use. Now it's really, really important that you do this first or you will end up with a completely wrong answer. You do not want that. So let's figure this out what the problem is actually asking us for. So at a glance this question looks like you need to figure out how many tablets Mary will be receiving. But it's not actually asking you that. It's asking you how many milligrams Mary will need to go home with. You need to read the entire question before you decide what the question is really asking. So let's write this out on the right hand side of the paper. We need the total milligrams that Mary will go home with. So step number one is to figure out what the question is asking you for. What do you need to end up with? Now step number two is to figure out what the order is. What did the Doctor originally order. What is the original order that we are trying to convert in this problem? In this example, the doctor ordered 250mg to be taken once per day. Now this is what the original order said. Said. This is what we're starting with. So you will write this on the left hand side of your paper. Now step number three is to figure out what conversion factors you need to use. These are the conversions that need to that you need to use to get you from here to there to the end result. Now, what medication or unit does the question make available to you? Are you needing to convert grams to milligrams, minutes to hours or milliliters to drops? Pick out the information that pertains to the answer that you need and cross off any unnecessary details in the practice problem. If the test is on paper, I like to physically cross off information I do not need to keep me from getting distracted. Now, in this case, we are keeping the dosage unit in milligrams, but we need to figure out how many milligrams she needs for 14 days. So for our example, the only information we need here is the prescribed dose of 250 milligrams. Often she takes it, which is once per day and how long she's going to be taking it for 14 days. We do not need to pay attention to the other details such as how long she's been in the hospital and how many milligrams the tablets are in the med cart. Because remember, this question is not asking us for the number of tablets she needs, it's asking us for how many milligrams she needs total. You'll write all of the conversions you'll need in the middle of the paper in between the order and then what you need. Now, when you're writing out these conversion factors, you need to make sure that they are structured correctly and that the units will cross off. It's really important that the units you don't need to end up with are at the end are on opposite sides of each other, one on the top and one on the bottom. That way they will cross each other out. Now, don't worry, I'm going to go through more practice problems and we're going to explain this more as we go. Now step number four is to solve the problem problem. Multiply across the top line, multiply across the bottom line and divide both of those numbers. This is a super awesome fraction trick that does the conversions for you and one of the top reasons I love writing out dosage calculation problems in this way using dimensional analysis. Now, you need to make sure that you set up it correctly in the first place. But once you make sure that it's all good to go, it's super easy to just multiply across the top, multiply across the bottom, and then divide. Now on to step number five, which is to write the answer appropriately. Oh, my goodness. One of the biggest mistakes that nursing students make when taking your dosage calculation exam is that you don't round correctly or you don't write the answer correctly. So there are two rules that you need to follow. The first rule is, when you're using this dimensional analysis method, don't round the answer until the very end. So as you're multiplying across the top and the bottom, just write out those numbers exactly how they are. Don't round them until after you divide and get that final answer. If you round the top and bottom numbers before you divide at the end, the answer may be off and you might get it wrong. And the second rule that you need to follow is to remember this mnemonic. Nurses are leaders, not followers. This means that you include leading zeros, but not trailing zeros. Let's say that your calculator said something like 0.5. We would not write this answer is just 0.5. Because imagine how easy it would be for that decimal point to get lost and then for it to turn into 5. That's no good. Also not write it as 0.50. For the same reason that decimal might get lost and someone might think it says 50. That would be very bad. So, friend, no trailing zeros. You need to watch them at all times, so keep them in the front. Now, the only correct way to write it is 0.5. Even if that decimal gets lost, it will look like 05, causing other nurses to double check where the decimal is. For our example, the answer is 3500mg. We would not write it as 3500.00mg, 3000 comma, 500mg or 03500mg. Simply write it as 3500 andmg. And finally, the last step is to check your work. It's super important to check that you got it right because we all make mistakes sometimes, but the patient's life depends on this. Friend, it's really important that you are diligent and that you double check your math. Seriously, friend, save yourself the stress and anxiety that comes with questioning yourself afterwards or hurting your patient just because you didn't take those extra few seconds to check your dosage calculations. So take a step back, breathe, and do the problem again. Safe nursing practice is always your number one priority. So now that we have gone through the steps, let's go over to my computer and solve some more practice problems together. But before we go over there, I want to give a shout out to Jessica Larson for our YouTube comment of the week. Your son. Super sweet. Jessica, you said. This video has been the most helpful video on studying pharmacology that I have found so far. Thank you a million and keep posting. Oh my gosh. Thank you so much for your sweet, sweet comment, Jessica. I so appreciate you. Now let's get started on those practice problems. Okay, so now we are at my computer and I am going to pull up some practice problems here for us to go through. So the first one says the doctor ordered 50 milligrams of metoprolol twice a day for hypertension. You only have 25 milligram tablets in the cart. How many tablets will you give your patient? So we are literally just going to walk through the steps here. So we first need to figure out what we need. That is step number one, what do we need to end up with at the end? So what this question is asking is we need tablets. How many tablets are we going to give to our patient? So that is what this question needs us to end up with. Now step number two is to figure out what the original order is. What is, what is the doctor ordered? What's the original order? So in this question, the doctor ordered 50 milligrams of metoprolol. So we're going to say 50 milligrams right here on the left hand side. So order goes on the left hand side. What you need goes on the right hand side. Now let's walk through the next step. Step number three is now, what conversions do you need? So the question gives us a conversion here. You only have 25 milligram tablets in the med cart. How many tablets will you give your patient? So we don't have any other conversions other than that. So we are starting with 50 milligrams because that's the order. And now we have 25 milligram tablets in the med cart. So how we're going to set this up here using dimensional analysis is to create kind of a railroad track structure like we did on our first problem. So 25, 25 milligrams is going to go down here. And we do that because they need to be opposite of each other. Anytime you Have a unit here and you want to cancel out this unit, you have to put it on the bottom as well in order for them to cancel out. So this would be 25 milligrams in one tablet. And now tablets is at the top here, which is exactly where we want it, because that's exactly what we need to end up with. So we have 50 milligrams, 25 milligrams per tablet. So 25 milligrams in one tablet. That's why this is our one conversion. And then for step number four is to just solve the problem. Now, here is where this dimensional analysis structure comes in. Real, real handy is because you could just multiply across the top and then multiply the bottom and then divide. So we are going to multiply 50 times one, which is just 50, and then we're going to, you know, multiply 25. Technically, we can put a one here because a fraction 50 milligrams over one, anything that, you know, doesn't have anything to go over, it always goes over one. So 50 divided by 25 is two. So we are going to be giving our patient two tablets. So the next step is to write the answer appropriately and then to check our answer. So because our answer right here is just two, you are just going to literally write it as two. You are not going to write it as 2.002 or 2.00. No, no and no, you just write it as two. Because again, we don't want to confuse anybody by having that decimal point get dropped here and someone thinking it's 20 or 200. No, it two tablets. So that is the first problem there. And then the next step that you would do, step number six is to check your answer. So you would always, always double check your work and just to make sure that you got the correct answer, so you would just do this pull process all again. Now let's do the next problem. The doctor orders 0.02 kg of medication a to be given to your patient at 0700 before they go into surgery. In your med Card, you have 400 grams of medication A. How much will you administer in grams? Now, for this question, wanted to throw in that medication A, because sometimes when you take your dosage calculation exams in nursing school, they won't actually put a medication name to it. So I just wanted to give this an example for you so you didn't kind of freak out when you saw your dose calc exam, and for some reason they didn't have an actual medication name. So this one is just medication A. So the first step that you're going to follow is to figure out what you need. So again, we're going to put need here on the right hand side of our paper. And so we need to end up with in this question is grams. Grams. So how many grams are we going to give this patient? And now step number two is what is ordered? What's the order? What did the doctor order? Now in this question, the doctor ordered 0.02kg of medication A to be given 700 before they go into surgery. So 0.02kg. So that is going to be over here on the left hand side for our order. And now step number three is what do we have have. You can write this here. I know I didn't do that last time. Or conversions. What are your conversions? So in this middle section here with your dimensional analysis, you're right. What do you, what, what do you have? What are the conversion factors you need to use? So in this scenario, we're going from kilograms to grams, and they do not give you a conversion factor. In here they say you have 400 grams of medication A in your med cart. But that doesn't really apply to us right now because we're just trying to figure out how many kilograms and a gram. Grams and kilograms, we don't know. So this is where you have to memorize your dosage calculation conversions and what conversion factors you need to use. So one thing that you just have to memorize is that there is 1,000 grams in one kilogram. So that is just something that you just have to keep to memory. 1,000 grams in one kilogram. So I wrote it like this, just like we walked through in the last problem is kilograms here needs to go on the bottom because it's up on the top here. And I'll put this over a one if that makes it easier for you to see. This one's on top and one is on the bottom. So these two units will cancel out kilograms. If you need to cancel a unit out, one needs to go on top and then the other needs to go on the bottom. So now we're just left with grams, which is beautiful because that's exactly what we need over here. So then we are just going to multiply straight across the top, then multiply straight across the bottom and then divide those two numbers so 0 times 1,000 is 20, and then 1 times 1 is 1. And so 20 divided by 1 is just 20 grams. And again, we are not going to round this this number at all. We're not going to change it, we're not going to do anything fancy with it. We're not going to write like 20.0 or anything like that. No, no, no. So this is step number, step number five, how to write out your, your answers. You would just write it as 20 grams. That's it. And now step number six, you would again check your answer just to make sure that you got it correct. And I also wanted to point out in this problem that this question is giving you some additional information that you don't need. You have 400 grams of medication a in your med cart. You only need 20 here. If perhaps your question said, you know, you had 10 grams here in your med cart and you need 20, then it might ask you something different. Like, you know, what would you do? You know, you would have to order some more medication, you would have to call the pharmacy. You would, you know, have to do all these crazy things to try to figure out. Oftentimes in your dose cock exams, they're not going to ask you that. They just want to know that you can do the math. So we're not going to worry about that. You have plenty of medication in your med car, so don't worry about that. I just threw this in to kind of distract you a little bit because you will see that in your dose calc exams they'll give you extra information that you don't need to use. So be be aware of that as you take your test. And now the next problem that we have is your patient's order says to give 30 milligrams of prednisone once per day. At 0700 you only have 10 milligram tablets in the med cart. How many tablets will you give your patient this morning? So again, we're just gonna walk through the easy peasy step of this process. So what do we need to end up with? We want to make sure that we're going to end up with the right things. And again, this question is asking us, how many tablets will you give your patient? So how many tablets? That's what we need to end up with. Step number two, what is the order? What does the order call for? And the order here says 30 milligrams of prednisone once per day. So again, I'm just going to put it over one because I think it's a little bit easier to see in the dimensional analysis method. Just so you know that that is top and bottom, 30 milligrams over one. So then what do we have? What do we have what's the conversion or conversions? So the conversions here that it gives us is we have 10 milligram tablets in the med cart. So each one single tablet is 10 milligrams and we have milligrams here up at the top. So what does that mean for us? Where do we need to put that 10 milligrams? We need to put that 10 milligrams here on the bottom, because we want milligrams to cross off. And so then we're going to put one tablet because each tablet is 10 milligrams, which is perfect. This is beautiful because we have tablets at the top. Tablets here is what we need milligrams crossed off. So this is exactly how we want to set it up. And then now the next step is to solve the problem. So we need to multiply straight across. So 30 times one is 30 and then 10 times one is 10. So 30 divided by 10 is three. So three tablets is what we would need to give our patient this morning, three tablets. So again, just like the previous problems, we don't want to Write it as 3.0 or 3.00 or anything crazy. That is step number five. Write your answer appropriately. It would just literally be three tablets. Now, this one here is going to be more fun and fancy. There are going to be a few more conversions that we need to do in this problem. So let's walk through it pretty slowly here. You're about to give acetaminophen to a toddler with a fever. The doctor's order says to give 15 milligrams per kilogram as needed. PRN, in your med car, you have acetaminophen, 160 milligrams per 5 milliliters. The child weighs 27 pounds. How many milliliters will you administer? So I know this problem gives you a lot of information, but don't worry. Just follow the steps step by step and we'll get the right answer. The first step is to figure out what we need. What do we need to end up with? And here in this problem, we need milliliters. How many milliliters will you administer to this patient? So that's what we need to end up with. Now, what is ordered? What does the doctor say? What's the order? And the order says to give 15 milligrams per one kilogram. So the order is 15 milligrams per one kil kilograms. So that's step number two. And now here in step number three, all we have to do is figure out our conversions. What do we have. What are the conversions that we need to use in order to end up with milliliters at the end? How do we get from here the order to there in the need? So what do we have? What are our conversions? So let's see, what does this problem give us? This problem gives us pounds. Well, we need to figure out pounds because the order gives us kilograms. So how many pounds in 1 kg? Well, there are 2.2 pounds in 1 kg. So that's just another conversion that you will need to memorize. There are 2.2 pounds in 1 kg. So how are we going to write this? We need to get rid of kilograms. So that means we need to put kilograms here on the top. So when 1kg is 2.2lbs, which make that a little darker there. So kilograms is going to cross off here because we put one on top and one on the bottom. So now we're left with milligrams and pounds. But that's not what this question is asking us. This question is asking us. We need to get to milliliters. So does this question say give us any other conversions on how to get to milliliters? And it does. In our med cart, it says we have acetaminophen, 160 milligrams per 5 milliliters. So here we would put we need 160 milligrams. We need milligrams to cross off because we don't need it. We need milliliters. We need to end up with milliliters. So we're gonna put 160 milligrams on the bottom. Then we're gonna put 5 milliliters here on the top because that is what we need to end up with is 5ml. Now milligrams is gonna cross off beautifully there. And so now we are left with milliliters. And that is exactly what we need to end up with. And now the last thing we need to do here is we still have pounds right here. We need to get rid of that. The child weighs 27 pounds. So we need to get rid of this pounds here. The way to do that is to put 27 pounds right here over one. So now 27 or I'm sorry, pounds here and pounds here. 2.2 is going to cross off. So now we are going to be left with solving the problem, which is step number four. We're going to multiply straight across the top. Then we're going to multiply straight across the bottom. So I have already done this so 15 times 1 times 5 times 27 is 2025 divided by 2.2 times 160 is 352. And then those divided. So 2025 divided by 352 equals. I'm actually gonna put it right down here, is 5.75. So 5.75 milliliters. So this is what we're going to come out with. Now here's where step number five of our process really comes in handy. 5.75 milliliters is not written correctly. So for milliliters, you do this to the tenth right here. So we just want to end right here. So we need to round. Anything five or above is going to round up. Anything four or below is going to round down. So in this situation, 5.75 gets changed to 5.8 milliliters. And that is how we would write our answer, 5.8 milliliters. And of course, step number six, we would go back and check our answer and just make sure we got everything correct. And the more you practice these problems, the more confident you're going to get, the better you're going to get at answering them. So even though you're now a pro at solving those dosage calculation problems, there are some key tips that you must remember when solving those problems, or you might end up getting them wrong. The first one is to read the entire question first. This tripped me up many times on my dose calc exams in nursing school. I would start reading the question. I would assume that I knew what it was asking, and I would solve it accordingly to what I thought. And then when I went to check my work, I found that I was solving for the wrong thing, like I had the wrong units or something like that. It's so easy to just assume that you know what the question is asking for when it's really asking for something different, something else. But you wouldn't catch on to that unless you actually read the entire question in the first place. So when you sit down to take your exam, make sure to read the entire exam question first. Now, tip number two is to learn and memorize the dosage calculation conversions that you need to know. There are no two ways about it, friend. You must memorize these. Like, one milligram equals 1,000 micrograms. One liter is 1,000 milliliters. There's three teaspoons in a tablespoon, 30 milliliters in an ounce, and one kilogram is 2.2 pounds. Now, I have a free cheat sheet with all of those listed, plus a lot more so it'll be really handy, handy for you as you learn these conversions. I'm going to put a link down below in the description for you to check it out. Now, the next tip I have for you is to use the dimensional analysis method like we did in all of our practice problems. I sometimes see nursing students using different formulas for solving these equations. That's okay if you're super confident in it. But if you're like me and you're not super confident in your math skills using dimensional analysis or the railroad method or railroad tracks, whatever you want to call it, it just works A to one better. Because literally all you have to do is put the numbers in the right place, multiply across the top, multiply across the bottom, and divide. That's it. It's foolproof. You will get the right answer every time as long as you set it up correctly. The next tip is to do practice problems over and over and over again. Really, the best way to gain confidence in solving dosage calculation problems is to practice it again and again and again. Now, if you're a nursing SOS member, sign into your dashboard and check out the dosage calculation workbook that we've got for you. That's filled with practice problems for you. Now, the more you practice, the better and more confident you're going to be at it. So make sure to practice, practice, practice. In the next video. We are going to cover how to calculate IV drip rates and do all of those tricky IV calculations. Make sure to watch it because it's going to make it so easy for you. Now click on one of these videos over here to keep rocking nursing school and become the nurse that God created only you to be. And I will see you in the next video.