2. Objectives
• Learn the formula for IV Flow Rate, Infusion
Time, and Total Volume
• Discuss Formula from the video
• Learn the common conversion factors
• Learn the common medication errors
3. When administering IV
• Know:
– Flow rate, infusion time, and total volume
– Use one of the following equations:
• flow rate (mL/hr) = total volume (mL) ÷ infusion time (hr)
• infusion time (hr) = total volume (mL) ÷ flow rate (mL/hr)
• total volume (mL) = flow rate (mL/hr) × infusion time (hr)
• For example, if you must administer 1 L (1,000 mL) of fluid
over 4 hours, use the first formula to calculate the flow
rate, like so:
• flow rate (mL/hr) = total volume (mL) ÷ infusion time (hr)
• flow rate (mL/hr) = 1,000 ÷ 4
• flow rate (mL/hr) = 250
• The flow rate is 250 mL/hr.
4. Common Conversions
• Common Conversion Factors in Medical Dosage Calculations
• As a healthcare professional, you have to convert patient weights, fluid
volumes, medication weights, and more. Conversion math isn’t hard to do
as long as you know the basic conversion factors. Here are the most useful
ones:
• Converting lb to kg and kg to lb
– lb = kg × 2.2
– kg = lb ÷ 2.2
• Converting mL to L and L to mL
– mL = L × 1,000
– L = mL ÷ 1,000
• Converting mg to g, g to mg, mg to mcg, and mcg to mg
– mg = g × 1,000
– g = mg ÷ 1,000
– mcg = mg × 1,000
– mg = mcg ÷ 1,000
5. Unacceptable Errors
• Making sure that you correctly calculate a
dose doesn’t matter much if the medication
itself is incorrect or the dosing instructions are
unclear. Some abbreviations in prescriptions
are unacceptable because they cause
ambiguity and confusion.
6. Unacceptable Errors
Abbrevi
ation
Mistaken Meanings Better Choice
DC or
D/C
Does it mean
“discontinue” or
“discharge”?
Write discontinue or
discharge.
HS
Does it mean “half-
strength” or “at
bedtime”?
Write at bedtime or a
designated time.
Also write out the specific
dosing strength and/or
quantity
QD
Does it mean “every day”
or “right eye”? QD looks
like OD, which means
“right eye.” (OS means
“left eye.”)
Write every day.
QOD
Does it mean “every other
day” or “daily”?
Write every other day or
daily, according to patient’s
needs.
MSO4
Does it mean “magnesium
sulfate” or “morphine
sulfate”?
Write magnesium sulfate or
morphine sulfate.
7. Unacceptable Errors
U or IU
Does it mean “unit” or
“zero”? Could it be
mistaken for “0” or “10”?
Write units.
IV
Does it mean
“intravenous,”
“international units,” or
“4”?
IV is an acceptable
abbreviation for
“intravenous,” but the doc
could write international
units or intravenous to be
clearer.
Or “4”
SQ or SC
Does it mean
“subcutaneous” or could it
be mistaken for “5Q” (“5
every”)?
Write Subq, subcut,
subcutaneous, or 5 every.
TIW
Does it mean “twice a
week” or “three times a
week” (the real meaning)?
Write twice a week or three
times a week.
cc
Does it mean “cubic
centimeter” or “milliliter”?
Could it be mistaken for
“00”?
Write milliliter or mL.
Ug or g
Does it mean “microgram”
or “Ugh”? Could it be
mistaken for mg?
Write microgram or mcg.
OD
Does it mean “once daily”
or “right eye”?
Write once daily or right eye.
