Hi, I'm Cathy with Level Up RN. In this video, I'll be explaining the rule of nines and the Parkland formula. And I'll be working through an example problem on my whiteboard that uses both of these things. 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.
So the rule of nines is a way for us to estimate the percentage of our patient's total body surface area that has been affected by a burn. And then we will use that percentage in calculating the amount of fluids that we need to administer to the patient, which can be quite a lot. So we'll use the Parkland formula to estimate the fluids after we get the percentage of total body surface area that is affected by the burn using the rule of nines. So if you look at my little very basic drawing of a person, you'll see that the percentages that are assigned to each body part are either 9% or divisible by nine. So if the entire head is burned, that would be 9%. If it was just the front of the head, then that would be 4.5%. If it was just the back, that would be 4.5%. The entire arm is 9%. If just the front of one arm was burnt, that would be 4.5%. And if it was just the back, that would also be 4.5%. The entire trunk is 36%. So if just the front of the trunk so the chest was burnt, that would be 18%. And if it was the back of the trunk, that would be 18% as well. If the groin is affected, that gets assigned 1%. So that's kind of the outlier in this rule of nines. And then each leg, if the entire leg is burned, that is 18%. If it is just the front of one leg, that is 9%.
So you definitely need to keep this in mind when calculating the percent of TBSA, total body surface area affected by the burn. Then we can calculate how much fluids the patient requires, so we do that with the Parkland formula. So the Parkland formula, the equation is right here. The amount of lactated Ringers that we need to administer to the patient in the first 24 hours is 4, so 4 milliliters of lactated Ringers times the patient's weight in kilograms times the percentage TBSA burned, which we estimate with the rule of nines. So we would multiply this out, and then half of this amount would need to be administered over the first 8 hours from the burn injury, and then the remaining half should be administered over the next 16 hours. Okay, so let's work through a problem so you can see how this works. In our example problem here, we have a patient that presents at the ER two hours after sustaining burn injuries to the front and back of both their legs. The patient weighs 132 pounds. And the questions we need to answer include A, what is the estimated percent TBSA affected? B, how many milliliters of lactated Ringers should be administered in the first 24 hours? And C, how many milliliters should be administered in the first 8 hours? So let's tackle A first.
So according to our example here, they sustained burn injuries to the front and back of both of their legs, so 18% is for the entire leg. So for this patient, they burned both legs entirely. So we have 18 plus another 18, so their percent TBSA is 36%. So that is the percent TBSA, and the answer to part A. Part B asks us how many milliliters of lactated Ringers should be administered in the first 24 hours. So we're going to use our Parkland formula to determine this. So we're going to take 4 milliliters of lactated Ringers times the patient's weight in kilograms, which we actually have to figure out, right? Because our patient weighs 132 pounds, but that is not their weight in kilograms. So if I take 132 pounds and I multiply by our conversion factor, which is 1 kilogram, equals 2.2 pounds, or you can simply divide 132 pounds by 2.2, we get 60 kilograms. So that is what we would plug into our equation over here. We have 4 times 60 times the TBSA percentage, which is 36. So if we calculate this out, we end up with 8,640 milliliters that needs to be administered in the first 24 hours. Okay? And that is the answer to part B.
Part C asks us how many milliliters should be administered in the first eight hours. And if you recall, when I explained this formula, half of this amount needs to be administered in the first eight hours. So if you take 8,640 divided by 2, you end up with 4,320 milliliters that needs to be given in the first eight hours. Now, keep in mind that our patient presented at the ER two hours after sustaining those burn injuries. So we are actually going to need to give this amount over six hours because two hours have already passed, and we need to get that much in the patient in that first eight hours since the time of injury. So this will be administered over six hours. Okay? And that's the answer to C. So the answer to C, in the first eight hours, it's 4,320 milliliters. If you were asked the time period over which this needs to be administered to this particular patient, it would be six hours because they showed up at the ER two hours after their burn injury.
