A physician orders 2gms of an antibiotic to be placed in 1000ml of D5W.
Using a constituted injection that contains 300mg/2ml, how many mls should
be added to the IV solution?
We ignore the dilution of the dextrose.
Assume the volume of injection is x ml, which contains 300mg/2ml, or 150mg/ml, or 0.15 g/ml
Volume of injection required
= 2/0.15 = 13.3 ml
Volume of D5W = 1000-x = 983.7 ml
Total volume = 1000 ml
total antibiotic = 13.3*0.15 = 2 g
On second reading, I realize that the idea is to mix a quantity of the injection into 1000 ml of D5W. This way, the volume of D5W does not have to be measured.
So simply mix 13.3 ml of injection into the bag of 1000 ml of D5W.
To answer this question, we need to calculate the quantity of the antibiotic solution required in milliliters (ml) based on the given concentration and desired strength.
1. Start by determining the total amount of antibiotic needed in grams. In this case, the physician ordered 2 grams.
2. Now, we need to convert the given concentration from milligrams (mg) to grams (g). The concentration of the constituted injection is 300mg/2ml. To do this conversion, we divide 300mg by 1000 to get the concentration in grams: 300mg = 0.3g.
3. Next, we calculate the total volume of the constituted injection required to provide 2 grams of the antibiotic. We can use the formula:
(Total quantity of antibiotic needed) / (Concentration of antibiotic in solution)
Substituting the values into the formula, we get:
Total quantity of antibiotic needed = 2g
Concentration of antibiotic in solution = 0.3g/2ml
Therefore, the total volume of the constituted injection required is:
(2g) / (0.3g/2ml) = (2g) / (0.15g/ml) = 13.33ml (rounded to two decimal places)
Hence, to obtain 2 grams of the antibiotic in 1000ml of D5W, you would add approximately 13.33ml of the constituted injection to the IV solution.