Hi. This is Cathy with Level Up RN. In this video, I will be going over a variety of dosage calculation problems that involve calculating a patient's IV fluid and medication intake over a period of time. These examples will include a situation where the patient's infusion rate changes during the course of therapy, a situation where the patient is receiving fluids through multiple IV lines, and a situation where the patient is receiving a continuous infusion as well as an IV piggyback medication. You can find all the information that I'll be covering in this video in our Level Up RN dosage calculation workbook. If you are in nursing school, then you know how important it is to master dosage calculations, and our workbook will help you do just that. In a nutshell, our workbook contains all different types of dosage calculation problems that you are likely to encounter in nursing school. And we demonstrate how to solve each problem using multiple methods so you can pick the way that makes the most sense to you.
With this first problem, we have an order for 1,250 milliliters to be given over 2 hours and then given at a rate of 125 milliliters per hour for 12 hours. And the question is, how much IV fluid will the patient receive in 6 hours? So for the first 2 hours, they will be getting 1,250 milliliters because that's what's ordered, so no math required to figure that one out. Then for the next 4 hours, they're going to be getting their IV fluids at a rate of 125 milliliters per hour. So if we take this rate, multiply it times 4 hours, we end up with 500 milliliters. So that's how much they'll get in this 4 hours. So if we add these two things together, 1,250 plus 500, we end up with 1,750 milliliters. And that is for 6 hours. And that's how you solve this problem.
All right. Let's work through another IV fluid and medication intake problem. In this problem, our patient has lactated Ringers ordered at 100 milliliters per hour through their primary line. And then through a secondary IV line, the patient is receiving cefazolin every eight hours in 50 mls of fluid running over an hour, and they're also getting clindamycin every six hours in 50 mL of fluid running over 30 minutes. How much IV fluid will the patient receive in 24 hours, round to the nearest whole number? All right. So our patient has two IV lines. And through their primary IV line, the only thing they're getting is the lactated Ringers. So to calculate how much fluid they're getting with those lactated ringers, they're getting it at a rate of 100 milliliters per hour. And if we multiply this rate times 24 hours, then we would get 2,400 milliliters. That's how much they're getting in 24 hours from that lactated Ringers going through their primary line.
Through the secondary line, they are getting cefazolin as well as clindamycin. So for the cefazolin, they are getting that every eight hours. So that's going to be three times in a 24-hour period. And each time they get it, they're getting 50 mls of fluid. And we don't actually care how long it takes to run in this particular problem. So they're getting 50 mls of fluid three times a day with the cefazolin. So 50 mls times three times a day because it's every eight hours. They're going to be getting 150 mls of fluid from that cefazolin. And then finally, with the clindamycin, clindamycin is being administered every six hours, so that is four times a day. And every time we give it, they are also getting 50 mls of fluid. So they're getting 50 mls every time we administer it, and they're getting it four times a day because it's every six hours. So if I multiply this out, I get 200 mls. Then all I need to do is add up these volumes. So if I take 2,400 plus 150 plus 200, I end up with 2,750 mls. And that is the total amount of IV fluids that the patient will receive in 24 hours.
Let's now work through our final IV fluid and medication intake problem. This particular problem deals with an IV piggyback medication. So when your patient is getting a continuous infusion of fluids and is also getting an IV piggyback medication, when that IV piggyback medication is running, the primary continuous infusion is not running during that time. So it adds a little more complexity when you are needing to calculate the total amount of IV fluids the patient is getting over a period of time. So in this example, we have a patient with lactated Ringers ordered at 125 milliliters per hour in their peripheral IV. The patient is also receiving metronidazole IV piggyback through this peripheral IV. And they're getting it every six hours in 100 mls of fluid running over 30 minutes each time. And then in addition, through their central line, the patient is receiving TPN at 75 milliliters per hour. And we want to know how much IV fluid the patient will receive in 24 hours, and we need to round to the nearest whole number. So as you can see, our patient has two IV lines. Through their peripheral IV, they're getting this continuous infusion of lactated Ringers. And then in every six hours, they're also getting metronidazole through IV piggyback. And then they have a separate line, their central line, where they're getting the TPN.
So let's first calculate how much fluids they're getting over 24 hours with their lactated Ringers, so that's the first thing we're going to figure out. So lactated Ringers is going to be running all the time except when the patient is getting their IV piggyback. And they're getting their IV piggyback every 6 hours, so that's four times a day. And each time they get their IV piggyback, it runs over 30 minutes, so basically, over 2 hours. If you take 30 minutes times four, you end up with 2 hours. That's the amount of time that their IV piggyback is running. And that means their lactated Ringers is not running during those 2 hours, which means that their lactated Ringers is running for 22 hours out of the 24 hours. Not the full 24 hours, but only the 22. So if we take 22 hours times the infusion rate, which is 125 milliliters per hour, then we end up with 2,750 ml that the patient is receiving per 24-hour period from their lactated Ringers.
Now, let's calculate how much fluid they're getting from their metronidazole. So metronidazole is being administered every six hours, so four times a day. And every time we give it, they're getting 100 milliliters of fluid. So if I take four times 100 milliliters over the course of 24 hours, they're getting 400 milliliters of fluid, so that's how much they're getting from their metronidazole. And then finally, we need to calculate how much fluid they're getting from their TPN, which is going through their central line. So their TPN is running at 75 milliliters per hour, and they're getting that over the 24 hours. So that's not stopping for any IV piggyback or anything. It's just running continuously. So if we multiply this out, we end up with 1,800 milliliters. So to calculate the total amount of IV fluids the patient will receive in 24 hours, we just need to add these three things together. And if we do that, we end up with 4,950 ml. And that is the answer to this question.
