are you wondering how to pass your nursing school dosage calculation exam or do you worry about those med math problems every time that you take a test because you know that they're going to show up somewhere well my friend worry no more because in this video i will be walking you through the simple six step process to getting every dosage calculation problem right every time on your nursing school exams so hit that subscribe button and click the notification bell and let's dive in [Music] all right so before we get into the nitty-gritty of solving dose calc problems there's a few things that we need to agree on first number one following our simple six step process is going to make all of the difference for you i have seen nursing instructors teach dosage calculations in a lot of different ways and so many of them are really just confusing and just not helpful that's why i created this step-by-step process now when you follow these six simple steps that we will go over in a minute you will get every dose celt question right just take it from our other students who love this dose calc system because it works my friend so please stick with these six simple steps and you will be golden now the second thing that we need to agree on is that we are not my friend not going to memorize any formulas i know i know what you are thinking formulas is probably what you're using right now and it's probably how your instructor teaches you but here's the deal my friend trying to memorize random formulas might work for super basic dose calc problems but it will fail you as you try to solve more complex problems problems like pitocin calculations heparin calculations and where you have to use multiple conversion factors to get the right answer so even though a formula might be working for you okay for now as you progress in your program and need to solve more complex dose calc problems you will run into major major issues using formulas i do not want you to get to your exam have a bunch of random formulas memorized and then realize that they don't work with the question that your dose calc exam is actually asking you or you don't know which formula to use for which problem because there's just so many of them to remember i see it happen all the time don't do that to yourself please so instead we use dimensional analysis which is also called the railroad method or railroad tracks which in my opinion is 1 000 times easier and it works every time no matter what problem that you are trying to solve if you want more help with dimensional analysis and answering dosage calculation problems correctly be sure to check out the nursing sos membership community where of course we have a full dose count course for you with step-by-step videos and tons of practice problems as well so if you're not quite confident with answering dose cut questions yet it will help you so much now let's dive into what this step-by-step system looks like and we'll walk through a dose calc problem as we go through it to help it all come together for you here's our practice problem the physician ordered one liter of normal saline to infuse over a span of eight hours the iv tubing that you're using is 20 drops per milliliter how many drops per minute will be infused so now that we have our practice problem let's look at how we set up every dose calc problem using the six simple steps now the first step is to look at the problem and figure out what unit we need to end up with at the end is the question asking you how many milliliters per hour the patient will receive is it asking you how many drops per hour will be given no it's asking how many drops per minute will be infused so step number one is to always read the question and figure out what you need to ultimately end up with at the end that way you know that you're solving for the right thing you don't want to get to the end of your exam and realize that you misread the question and then got it wrong so always make sure to start with the end in mind what unit do you need to end up with at the end and you'll write this unit on the right hand side of your paper so for our practice problem here the unit we need to end up with at the end of solving this dose calc problem is drops per minute we are trying to figure out how many drops per minute will be given to our patient now step number two is to look at the problem again and then see what the original order says what was the doctor ordering did the doctor order a certain number of milligrams maybe grams or milliliters or something else so reread the question again and then look at what the order says in our question the physician ordered one liter of normal saline to infuse over a span of eight hours that's what the order says so on the left hand side of your paper you will write what the doctor ordered now in this case we will write one liter over eight hours because we need to give one liter of fluid over an eight hour time frame so you'll write it as one liter divided by eight hours so now let's have a look at what we have we need drops over minutes but we currently only have liters over hours so somehow we need to get from liters over hours to drops over minute so this is where your conversion factors come into play this is step number three what conversions do you need to use to solve this problem now here's where most nursing students get stuck when you look at a dose calc problem like this and you need to somehow go from liters over hours to drops over minutes you kind of freeze and think oh no i have no idea how to do this i totally get it my friend i am a pro at freaking out when it comes to math i promise you i am really not a math person by any stretch of the imagination and that is why i love this six step process so much it works every time and when you lay it out this way it's so much easier to visualize so take a deep breath and let's look at this together now we know that we need to get from liters over hours to drops over minutes now the trick to dimensional analysis is that units need to cross themselves out we need to eliminate them so because we don't need to end up with liters over hours at the end we somehow need to get rid of those units and we do this by using conversion factors to cancel out those units the unit that we want to end up with at the end must be aligned with these railroad tracks so in our case here we want to make sure that we end up with drops or gtts on the top of our railroad track and minutes on the bottom of the railroad tracks now all other units need to cancel themselves out and i'll show you how to do that right now so a trick i use when solving any dose count question is to look at the original problem and see if they give you any conversion factors first in that problem so let's read it again now the physician ordered one liter of normal saline to infuse over a span of eight hours the iv tubing you're using is 20 drops per milliliter how many drops per minute will be infused did you catch it do you see the conversion factor that the question actually gives us we already know what we need drops per minute and we already know what the order is one liter over eight hours so that leaves us that iv tubing conversion the iv tubing gives 20 drops per milliliter bingo so let's write that in the middle and see what happens so now we have one liter over eight hours 20 drops over 1 milliliter and at the end we have drops over minutes now this is good because we have drops or gtds on the top of the railroad tracks right where it needs to be now remember whatever unit we want to end up with at the end on top is what needs to be on the top of the railroad tracks and whatever unit we need to end up with on the bottom at the end is what needs to be on the bottom of the railroad tracks but now there's still a problem we still have the units of liters milliliters and hours to get rid of we don't need to end up with those at the end and we somehow need to get minutes on the bottom so let's look at where we're at again now liter over hours drops over milliliters we want to keep the drops because that unit needs to stay until the end we need that one on the top of the railroad tracks but we need to get rid of the liters and the milliliters so what's another conversion that we could use the easiest one will be this there are 1 000 milliliters in one liter so 1000 milliliters over 1 liter when we write that in let's see what happens we have milliliters on both the top and bottom of our railroad tracks so they cancel each other out and we have leaders on both the top and the bottom of our railroad tracks so those can cancel each other out too any unit that is on both the top and the bottom of the railroad tracks cancels each other out so now what are we left with we now have one over eight hours 20 drops over one and one thousand over one the other units are cancelled so drops is still on the top of the tracks where it needs to be we didn't cancel that one out and we still have hours on the bottom that we need to somehow convert to minutes why because we need to end up with minutes at the end of the problem so let's do that next how can we get from hours to minutes what conversion factor can you think of well there's 60 minutes in one hour right so 60 minutes over 1 hour or 1 hour over 60 minutes do we need to write it as 60 minutes over 1 hour or 1 hour over 60 minutes if we leave it as 60 minutes over 1 hour then minutes will be on the top of the railroad tracks and that's not where we want it we need it on the bottom so we'll need to write it as 1 hour over 60 minutes now that puts minutes on the bottom where it needs to be and now we have hours on the bottom here and hours on the top here and those can cancel each other out so remember those two principles of dimensional analysis that we talked about when you write a unit on both the top and the bottom of the railroad tracks they will cancel each other out and principle number two whatever unit you want to end up with at the end on the top needs to be on the top of the railroad track and whatever unit you need to end up with at the end on the bottom needs to be on the bottom of the railroad track now don't be afraid to play around with these conversion factors if you need to there has been many a time where i needed to put in a conversion factor and see if it works and then erase it if it doesn't so sometimes you just need to use a good old-fashioned trial and error process if you're really not sure what conversion factors to use so don't be afraid to try different ones put them in different places to see what works so now that we have all of our conversion factors in place they look good and we ended up with the right units on the top and the bottom of the tracks now we need to multiply it so step number four is to just multiply straight across the top of the railroads and then multiply straight across the bottom of the railroad tracks and then divide those two numbers so let's do it 1 times 20 times one thousand times one equals twenty thousand and eight times one times one times sixty equals four eighty so now that we've multiplied across the top and the bottom of the tracks we need to divide now those two numbers so 20 000 divided by 480 is 41.6 so 41.6 drops per minute is what we have now so now let's move on to step number five which is to use the correct rounding rules and the rules for zeros so any time we have we are writing out drops per minute it will always be a whole number when you're looking at your iv tubing and counting the drops manually in that drip chamber are you able to count out 0.6 of a drop no you are definitely not so we always round drops per minute to a whole number so in this case 41.6 drops per minute would become 42 drops per minute now remember this rounding rule five and above and you round up four and below you round down so because we had point six of a drop it's greater than five so we need to round up to the next whole number which would be 42. so the answer is 42 drops per minute and step number six is to of course double check your math rework the problem again to make sure that you got it correct dosage calculations are really really important to get right every time it can literally mean life or death for a patient so it's always important to double check yourself and to make sure that you got the correct answer now my friend there are three ways that i can help you more with dose calc in nursing school number one download this free cheat sheet that walks you through the step-by-step process for acing dose calc now don't miss out on that free resource for you now number two get the nursing school dose calc box so you can snag the flash cards get the full workbook and practice problems and all the other goodies that come in that box to help you build confidence and pass your dose calc exam and of course as always if you want me to hold your hand throughout nursing school please don't miss out on joining the nursing sos membership community it is filled with step-by-step nursing lectures to help you understand everything faster including a full dose count course with additional practice questions for you to go through plus you will get access to our fantastic nurses so you can ask questions anytime that you get stuck we are here to help the links to all of those things are in the description down below and if you like this video be sure to hit that like button leave a comment below to let me know that it was helpful for you if you liked this step-by-step process and want more videos like this and of course click that subscribe button and hit the notification bell so you never miss a video and click on one of these videos right over here so you can keep rocking nursing school and as always my friend go become the nurse that god created only you to be and i'll see you next time on the nursing school show take care bye