1 of 36
Term
How many milliliters should be administered to a 100-kg patient that
needs 50 mg of a 2.5% solution?
Give this one a try later!
,10 mL
To solve this question, it is very important to know that there are 1000 micrograms in
1 milligram. Similarly, there are 1000 milligrams in 1 gram.
First, convert body weight to kilograms.
2200 lbs / (2.2 lbs/kg) = 1000kg
1000kg x (10 micrograms/kg) = 10,000 micrograms
10,000 micrograms / (1 milligram/1000 micrograms) = 10 milligrams (Notice the
micrograms cancel out.)
10 mg / (1 mg/ml) = 10 ml
90 mL/hr
There are several ways to calculate maintenance fluids. Some are more accurate
than others, with the more accurate ones requiring more complex math. Fortunately,
in most patients, being off by a few milliliters does not adversely affect the patient.
The most basic calculation to approxiamte maintenance rate fluids in a dog is:
60mL/kg/day
80 pounds/2.2= 36 kg
60mL X 36 kg = 2160 mL per day
2160 mL/24 hours in a day = 90 mL per hour
2 ml
Percent is equal to weight (in Grams) / 100 parts volume (in mLs)
(This is based on water since 1 mL weighs 1 Gram):
Example: A 3% solution: 3 Grams / 100 mL or 3000 mg / 100 mL or 30 mg/mL
The easiest way to remember is to just add a zero onto any percentage for
, the milligrams (i.e. 2% solution = 20 mg/ml; 10% solution = 100 mg/ml, etc.)
In this situation a 2.5% solution is equivalent to 25 mg/ml. Therefore:
50 mg / (25 mg/ml) = 2 ml
1 mL
A 10-kg patient will need 30 mg/day of the medication (10 kg x 3 mg/kg/day)
Since the fluid is being administered at an hourly rate we need to figure out how
much medication we are administering per hour.
30 mg/day / (24 hr) = 1.25 mg/hr
To determine how much volume of the medication is needed the following math is
performed:
1.25 mg/hr / (30 ml/hr) x (250 ml) = 10.4 mg (Notice how the units cancel out)
10.4 mg / (10 mg/ml) = 1 ml
Don't know?
2 of 36
Definition
32mL
Constant rate infusions are not something that an entry level technician
would typically perform. However, the VTNE may have some questions
on CRI and it will benefit you to know how to do these calculations. To
solve this problem, break down the basic parts to make it less
overwhelming:
, 1) Convert pounds to kilograms- Note that in this problem the units are
already in kg so no conversion is necessary. Make sure to pay attention
to this.
2) Calculate the number of hours an infusion will last by dividing the
volume in the bag (1 Liter, or 1,000 mL) by the rate per hour: 1,000
mL/100mL/hr = 10 hours
(If the problem asks for a dose per minute, you will need to multiply the
hours by 60 to convert to minutes, but since this problem asks for
ug/kg/HOUR, you do not need to further convert)
4) Now plug into the equation: 4 ug/40kg/10 hours= 1600 ug
5) Now convert the ug into mg by dividing by 1,000: 1600/1,000 = 1.6 mg
6) Calculate the quantity of fentanyl to add by now dividing the 1.6 mg
by the concentration of the drug (0.05 mg/mL) : 1.6mg/0.05mg/mL = 32
mL
To be truly accurate when adding drugs to a bag like this, you should
discard 32 mL of fluids from the bag prior to adding the 32 mL of
fentanyl.
Give this one a try later!
"Zoe", a 40 kg Labrador Retriever is recovering after a liver mass resection.
The doctor asks you to start "Zoe" on a fentanyl constant rate infusion at 4
micrograms per kilogram per hour (ug/kg/hr). The concentration of fentanyl is
0.05mg/mL. The fluid rate is currently set at 100 mL/hour. How much fentanyl
will you add to a liter of Normosol-R? (CRI)
Term
How many milliliters should be administered to a 100-kg patient that
needs 50 mg of a 2.5% solution?
Give this one a try later!
,10 mL
To solve this question, it is very important to know that there are 1000 micrograms in
1 milligram. Similarly, there are 1000 milligrams in 1 gram.
First, convert body weight to kilograms.
2200 lbs / (2.2 lbs/kg) = 1000kg
1000kg x (10 micrograms/kg) = 10,000 micrograms
10,000 micrograms / (1 milligram/1000 micrograms) = 10 milligrams (Notice the
micrograms cancel out.)
10 mg / (1 mg/ml) = 10 ml
90 mL/hr
There are several ways to calculate maintenance fluids. Some are more accurate
than others, with the more accurate ones requiring more complex math. Fortunately,
in most patients, being off by a few milliliters does not adversely affect the patient.
The most basic calculation to approxiamte maintenance rate fluids in a dog is:
60mL/kg/day
80 pounds/2.2= 36 kg
60mL X 36 kg = 2160 mL per day
2160 mL/24 hours in a day = 90 mL per hour
2 ml
Percent is equal to weight (in Grams) / 100 parts volume (in mLs)
(This is based on water since 1 mL weighs 1 Gram):
Example: A 3% solution: 3 Grams / 100 mL or 3000 mg / 100 mL or 30 mg/mL
The easiest way to remember is to just add a zero onto any percentage for
, the milligrams (i.e. 2% solution = 20 mg/ml; 10% solution = 100 mg/ml, etc.)
In this situation a 2.5% solution is equivalent to 25 mg/ml. Therefore:
50 mg / (25 mg/ml) = 2 ml
1 mL
A 10-kg patient will need 30 mg/day of the medication (10 kg x 3 mg/kg/day)
Since the fluid is being administered at an hourly rate we need to figure out how
much medication we are administering per hour.
30 mg/day / (24 hr) = 1.25 mg/hr
To determine how much volume of the medication is needed the following math is
performed:
1.25 mg/hr / (30 ml/hr) x (250 ml) = 10.4 mg (Notice how the units cancel out)
10.4 mg / (10 mg/ml) = 1 ml
Don't know?
2 of 36
Definition
32mL
Constant rate infusions are not something that an entry level technician
would typically perform. However, the VTNE may have some questions
on CRI and it will benefit you to know how to do these calculations. To
solve this problem, break down the basic parts to make it less
overwhelming:
, 1) Convert pounds to kilograms- Note that in this problem the units are
already in kg so no conversion is necessary. Make sure to pay attention
to this.
2) Calculate the number of hours an infusion will last by dividing the
volume in the bag (1 Liter, or 1,000 mL) by the rate per hour: 1,000
mL/100mL/hr = 10 hours
(If the problem asks for a dose per minute, you will need to multiply the
hours by 60 to convert to minutes, but since this problem asks for
ug/kg/HOUR, you do not need to further convert)
4) Now plug into the equation: 4 ug/40kg/10 hours= 1600 ug
5) Now convert the ug into mg by dividing by 1,000: 1600/1,000 = 1.6 mg
6) Calculate the quantity of fentanyl to add by now dividing the 1.6 mg
by the concentration of the drug (0.05 mg/mL) : 1.6mg/0.05mg/mL = 32
mL
To be truly accurate when adding drugs to a bag like this, you should
discard 32 mL of fluids from the bag prior to adding the 32 mL of
fentanyl.
Give this one a try later!
"Zoe", a 40 kg Labrador Retriever is recovering after a liver mass resection.
The doctor asks you to start "Zoe" on a fentanyl constant rate infusion at 4
micrograms per kilogram per hour (ug/kg/hr). The concentration of fentanyl is
0.05mg/mL. The fluid rate is currently set at 100 mL/hour. How much fentanyl
will you add to a liter of Normosol-R? (CRI)
