## Ex: IV Dosage Calculation - Flow Rate Requiring Five Steps - Buy Bentyl ### Ex: IV Dosage Calculation – Flow Rate Requiring Five Steps

#### By Bryan Wright 0 Comment October 16, 2019  application, Conversions, convert, cross, equations, flow, intravenous, IV, james, mathispower4u, Medical, milliliters, milliunits, min, minute, ML, multiple, multiply, nurse, nursing, per, proportions, rate, Solve, sousa, Steps, the, units

You receive an order for 10 milliunits per
kilogram per minute. The solution is labeled 40
units per 100 milliliters. The patient weights 198 pounds. What is the correct rate or flow rate in milliliters per hour? So to find the flow rate, we’ll have to perform several conversions. Notice how the order is given
in milliunits per kilogram but the weight is given in pounds. Let’s begin by converting
198 pounds to kilograms, and we’ll do this using a proportion. Looking at our conversions below, notice that one kilogram
is equal to 2.2 pounds, so we can say one
kilogram is to 2.2 pounds as an unknown number of kilograms, which I’ll call X kilograms,
to the weight at 198 pounds. And before we cross
multiply and solve for X, it’s important to recognize that we have the same units on the top and
the same units on the bottom. If we did not have this, we’d have to perform a conversion first. But because we do, 2.2 times X is 2.2 X must equal one times 198. Dividing both sides by 2.2, this comes out very nicely on the right. This is equal to 90, so 90 kilograms is equal to 198 pounds. Now that we know the
patient’s weight in kilograms, let’s determine how many milliunits the patient needs per minute. The order calls for 10
milliunits per kilogram, so 10 milliunits per one kilogram must equal an unknown
number of milliunits, we’ll call it Y milliunits, to the patient’s weight of 90 kilograms. Once again, we have the same units on top, same units on the bottom, so we can cross multiply and solve for Y. So one times Y is Y. 10 times 90 is 900. Which means the patient needs
900 milliunits per minute. So again, we can write the order
for this particular patient as 900 milliunits per minute, but notice how we want the flow
rate in milliliters per hour so now let’s convert this
rate into milliunits per hour, and then we’ll determine how
many milliliters we need. So for the next proportion,
900 milliunits per one minute must be equal to some
number of milliunits, we’ll call it Z milliunits, per one hour, but because we need the
same units on the bottom, notice here we have minutes,
instead of writing one hour, one hour is equal to 60 minutes, so I’ll write this as 60 minutes. Again, we have the same
units on the bottom, same units on the top, so now we can cross
multiply and solve for Z. One times Z is Z. 900 times 60 is equal to 54,000, which means now we can write the order as 54,000 milliunits per one hour. For the next step, we’ll
convert the 54,000 milliunits to units, then once we
find the number of units, we can determine the number
of milliliters per hour. Let’s go and continue
this one the next slide. Again, now we’re going to
convert milliunits to units. Going back to the previous
slide just for a moment, notice how 1,000 milliunits
is equal to one unit. So this will give us the
left side of the proportion. 1,000 milliunits is to one
unit as 54,000 milliunits is to an unknown number of
units, we’ll say A units. Once again, we have the same units on top, same units on the bottom. Cross multiply and solve for A. 1,000 times A, or 1,000 A
must equal one times 54,000. Divide both sides by 1,000. So we have A equals 54. So if A’s equal to 54, that
means 54,000 milliunits is equal to 54 units, and therefore, we can now write the order
as 54 units per hour. Now we need one more proportion. We need to determine how many milliliters is required for 54 units. So going back to the given
information just for a moment, notice how the solution has a rate of 40 units per 100 milliliters. So they can say 40 units
is to 100 milliliters as 54 units is equal to an
unknown number of milliliters, which we’ll say B milliliters. And finally, once again, we
have the same units on the top, same units on the bottom, so now we can cross
multiply and solve for B. So we have 40 times B, that’s 40 B, equals 100 times 54, that’s 5,400. Divide both sides by 40. 5,400 divided by 40 is equal to 135. Which means that the
patient requires 54 units, that would be equivalent to
135 milliliters of the solution and therefore, the flow
rate for this patient is 135 milliliters per hour. I hope you found this explanation helpful.