Dosage Calculations Chapter 52 Latest
2023 Already Passed
Ensuring Safe Dosage Calculations ✔✔In order to be able to calculate dosages, you must
understand and be able to perform basic math accurately. Whether you are using a calculator or
doing it by hand, accuracy is key. Remember that a minor mistake in basic math can mean major
errors in the patient's medication. When you perform any calculation, think about the answer you
obtain and determine if it is reasonable.
Consider this example: While performing a calculation, a medical assistant adds the following
numbers: 21¾, 12½, and 1½. He calculates an answer of 49¼. Before he accepts this answer as
correct, however, he asks himself, "Is this reasonable?" In order to answer this question, he does
a quick estimation. First, he adds the whole numbers from each of the mixed numbers in the
problem: 21 + 12 + 1 = 34. Then he rounds each mixed number up to a whole number and adds
them: 22 + 13 + 2 = 37. He recognizes that the correct answer to the problem must be between
34 and 37, so his original answer is incorrect. He probably entered one of the numbers into his
calculator incorrectly. When he repeats the original calculation, he now comes up with an answer
of 35¾. This is between the values that he expected based on his estimate, so it is a reasonable
answer to the problem.
Think about the example. When performing calculations, there are many steps in which an error
might be made. In this case, a number had been entered incorrectly into a calculator. While
, errors like this can happen to anyone, they can usually be detected by performing a quick check
to see if the answer is reasonable. You should develop the habit of asking yourself the same
question every time you perform a calculation. When performing a calculation, analyze the
problem and try to estimate a reasonable range for the answer. This critical thinking skill can
help you to detect errors and should become a part of every calculation you perform.
Measurement Systems ✔✔Three systems of measurement are used in the United States for
pharmacology and drug administration. These include metric, apothecary, and household
systems. Metric is the most commonly used system. Although apothecary and household systems
are rarely used, basic knowledge of these systems may be needed.
To understand drug measurement, focus primarily on remembering the basic unit of volume and
weight. Volume refers to the amount of space a drug occupies. Weight refers to its heaviness.
Length, which is also a basic unit, is discussed in the Vital Signs and Measurements chapter.
Metric System ✔✔Like the decimal system, the metric system is based on multiples of 10. The
greater confidence you have working with decimals, the more comfortable you will be working
with metric units. See the Caution: Handle with Care feature Working with Decimals. The basic
units of volume and weight in the decimal-based metric system are liters (L) to measure volume
and grams (g) to measure weight. Prefixes are added to these basic units of measurement to
indicate multiples, such as kilogram (kg), or fractions, such as milliliter (mL) or microgram
2023 Already Passed
Ensuring Safe Dosage Calculations ✔✔In order to be able to calculate dosages, you must
understand and be able to perform basic math accurately. Whether you are using a calculator or
doing it by hand, accuracy is key. Remember that a minor mistake in basic math can mean major
errors in the patient's medication. When you perform any calculation, think about the answer you
obtain and determine if it is reasonable.
Consider this example: While performing a calculation, a medical assistant adds the following
numbers: 21¾, 12½, and 1½. He calculates an answer of 49¼. Before he accepts this answer as
correct, however, he asks himself, "Is this reasonable?" In order to answer this question, he does
a quick estimation. First, he adds the whole numbers from each of the mixed numbers in the
problem: 21 + 12 + 1 = 34. Then he rounds each mixed number up to a whole number and adds
them: 22 + 13 + 2 = 37. He recognizes that the correct answer to the problem must be between
34 and 37, so his original answer is incorrect. He probably entered one of the numbers into his
calculator incorrectly. When he repeats the original calculation, he now comes up with an answer
of 35¾. This is between the values that he expected based on his estimate, so it is a reasonable
answer to the problem.
Think about the example. When performing calculations, there are many steps in which an error
might be made. In this case, a number had been entered incorrectly into a calculator. While
, errors like this can happen to anyone, they can usually be detected by performing a quick check
to see if the answer is reasonable. You should develop the habit of asking yourself the same
question every time you perform a calculation. When performing a calculation, analyze the
problem and try to estimate a reasonable range for the answer. This critical thinking skill can
help you to detect errors and should become a part of every calculation you perform.
Measurement Systems ✔✔Three systems of measurement are used in the United States for
pharmacology and drug administration. These include metric, apothecary, and household
systems. Metric is the most commonly used system. Although apothecary and household systems
are rarely used, basic knowledge of these systems may be needed.
To understand drug measurement, focus primarily on remembering the basic unit of volume and
weight. Volume refers to the amount of space a drug occupies. Weight refers to its heaviness.
Length, which is also a basic unit, is discussed in the Vital Signs and Measurements chapter.
Metric System ✔✔Like the decimal system, the metric system is based on multiples of 10. The
greater confidence you have working with decimals, the more comfortable you will be working
with metric units. See the Caution: Handle with Care feature Working with Decimals. The basic
units of volume and weight in the decimal-based metric system are liters (L) to measure volume
and grams (g) to measure weight. Prefixes are added to these basic units of measurement to
indicate multiples, such as kilogram (kg), or fractions, such as milliliter (mL) or microgram
