Basic Math and Calculate an IV Flow Rate
INTRODUCTION
As a Health Care Specialist on the battlefield or in a hospital setting, you may be called upon to perform tasks, which involve a basic knowledge of mathematics. For example, the percentage of burns covering a casualty's body, the patient's weight in pounds or kilograms, or the correct dosage of a prescribed medication. One task that you will be called upon to do is determine the flow rate for an intravenous infusion. In dealing with patients whose blood pressure and bleeding are under control, the IV needs to be infused at a specific rate.
(1) Line up numbers exactly.
(2) Carry numbers from one column to the next.
17 + 29 = 46
36 + 48 = 84
73 + 47 = 120
(3) Solve the following problems.
(a) 34 + 17 = 51
(b) 65 + 43 = 84
(c) 89 + 31 = 120
(1) Line up numbers correctly.
(2) The larger number always goes on top.
(3) Subtract correctly.
15 - 4 = 11
98 - 73 = 25
45 - 38 = 7
(4) Solve the following problems
(a) 34 – 17 = 17
(b) 65 – 43 = 22
(c) 89 – 31 = 58
(1) Line up the columns correctly
(2) Carry numbers as you multiply
(3) Add correctly.
15 x 6 = 90
11 x 42 = 462
14 x 12 = 168
(4) Solve the following problems.
(a) 22 x 11 = 242
(b) 13 x 9 = 117
(c) 14 x 56 = 784
(1) Be accurate
(2) Be aware of zeroes
6 42 =
8 56 =
7 70 =
(3) Solve the following problems
(a) 5 65 =
(b) 3 78 =
(c) 3 871 =
FRACTIONS
(1) Rules for solving proper fraction
(a) Reduce proper fraction to lowest term
(b) Divide numerator and denominator by the same number
(2) Example: 5/10 (5/5=1, 10/5=2)=1/ 2, 9/27 (9/9=1, 27/9=3)= 1/3
(1) Rules
(a) Divide denominator into numerator
(b) Remainder becomes new numerator
(c) Place numerator over denominator
(d) Reduce to lowest term
(2) Example: 25/3 = 8 1/3
(1) Rules for solving mixed fraction
(a) Multiply whole number by denominator
(b) Add to numerator. This sum is the new numerator
(c) Place over the denominator
(d) Reduce to lowest term
(2) Example: 3 5/6=(3x6+5)=23/6=3.833
A decimal number expresses less than a whole number
The decimal point is a dot
All numbers to the left of the decimal are whole numbers
All numbers to the right of the decimal are decimal numbers
The first number to the right of the decimal is tenths; the second is hundredths; the third is thousands
Examples: 5.125 is read 5 (whole number); point; 1 (tenths), 2 (hundredths),
5 (thousands)
If there isn't a whole number in a decimal answer, place a zero to the left of the decimal. Examples: 0.75, 0.2
Zeros at the end of a decimal number do not add value and may be eliminated. (Example: "2.0" may be written as "2")
In division, the divisor is the number following the "/" symbol and is placed outside the box. The dividend is the number to be divided and is placed inside the box. The answer is also referred to as the quotient.
When rounding, if number is 5 or greater, round up; if number is less than 5 round down.
3.43 + 16.021= 19.451 or 19.5
5.053 - 2.09= 2.963 or 3.0
5.02 x .6 = 3.012
25.155 / .05= 503.1
(1) Total volume to be infused
(2) Time period over which it is to be infused
(3) Properties of the administration set (how many drops per milliliter it delivers). This information is found on the box containing the administration set.
Formula for calculating IV flow rate:
(1) Volume to be infused X Drops/ml of infusion set
Total time of infusion in minutes
PROBLEMS:
(1) SFC Murray received a physician's order to administer an intravenous infusion. The order states that the total volume of 1000 ml is to be delivered over a 4-hour period. The IV set that is to be used will deliver 20 drops per milliliter.
How many drops per minute should be administered?
(2) CPT Smith’s IV is ordered at 150 ml to be delivered over 1 hour. The administration set being used delivers 20 gtt/ml. Calculate the drops/minute to be administered.
(3) Mr. Cadiz has an order for 1000 ml of D5W. The administration set delivers 10 gtt/ml. Calculate the flow rate of the fluid to be infused over 4 hrs and 2 hrs.
Shock is a state of
inadequate tissue perfusion that can be caused by a variety of disease states
and injuries. If the syndrome is severe or prolonged, it may become
irreversible, resulting in multiple organ failure and death. Initiating and
maintaining an IV infusion may make a difference between saving or losing a
patient's life. The ability to properly calculate and regulate the flow of IV
fluid is essential to the care of the patient with an IV.
Homework, Self Test
A. Reduce the following fractions to its lowest terms:
1. 2/12= 6. 9/24=
2. 3/18= 7. 7/21=
3. 3/33= 8. 4/32=
4. 6/48= 9. 4/16=
5. 8/64= 10. 5/20=
B. Change the following mixed numbers to improper fractions:
1. 1 1/3= 6. 6 7/8=
2. 2 2= 7. 7 5/9=
3. 3 1/5= 8. 8 4/2=
4. 4 2/5= 9. 9 2/3=
5. 5 3/4= 10. 10 2=
C. Multiply the following fractions and reduce to lowest terms:
1. 3/5 x 6/7= 6. 2/5 x 8/11=
2. 4/5 x 1/8= 7. 9/10 x 7/9=
3. 11/12 x 3/4= 8. 8/17 x 4/3=
4. 2/3 x 1/6= 9. 5/8 x 9/4=
5. 7/8 x 9/16= 10. 5/8 x 3/4=
D. Multiply the following decimals:
1. 15.4 x 0.7= 6. 0.058 x 0.2=
2. 21.7 x 0.83= 7. 1.25 x 0.2=
3. 0.127 x 0.04= 8. 0.032 x 0.3=
4. 63.9 x 0.5= 9. 2.87 x 10=
5. 12.7 x 0.8= 10. 41.2 x 0.8=
E. Change the following fractions to decimals and round to the nearest hundredth (2nd decimal place).
1. 1/5= 3. 1/4=
2. 4/5= 4. 22/25=
F. Change the following decimals to fractions and reduce to lowest terms.
1. 0.45= 3. 1.25=
2. 0.22= 4. 0.98=
G. Calculate the following IV drip rates:
1. Cpt Smith has an IV infusing at 100ml/hr. The physician changes the order to state that the IV is to be Lactated Ringer's Solution at 150 ml/hr. The administration set delivers 20 drops/ml. How may drops/minute should be delivered? .
2. Mrs. Wilson's physician has order an IV of D5W at 100ml/hr. The administration set delivers 15 drops per ml. How may drops per minute should be administered?