Q. 2.65 - An Introduction to General, Organic, and Biological Chemistry

Question

Using conversion factors, solve each of the following clinical problems:

a. A nurse practitioner prepares $500. \mathrm{mL}$ of an IV of normal saline solution to be delivered at a rate of $80. \mathrm{mL}/\mathrm{h}$. What is the infusion time, in hours, to deliver $500. \mathrm{mL}$?

b. A nurse practitioner orders Medrol to be given $1.5 \mathrm{mg}/\mathrm{kg}$ of body weight. Medrol is an anti-inflammatory administered as an intramuscular injection. If a child weighs $72.6 \mathrm{lb}$ and the available stock of Medrol is $20. \mathrm{mg}/\mathrm{mL}$, how many milliliters does the nurse administer to the child?

Step-by-Step Solution

Answer

(a) The infusion time to deliver $500 \mathrm{mL}$ is $6.3 \mathrm{h}$

(b) The $2.5 \mathrm{mL}$ nurse administers to the child.

Part (a) Step 1: Given information

We need to find out the infusion time in hours to deliver $500 \mathrm{mL}$

Part (a) Step 2: Explanation

We know that

The $80 \mathrm{mL}/\mathrm{h}$ means $80 \mathrm{mL}=1 \mathrm{h}$

Therefore, infusion time to deliver $500 \mathrm{mL}$is,

$\frac{1 \mathrm{h}}{80 \cancel{\mathrm{mL}}}\times 500 \cancel{\mathrm{mL}}=6.3 \mathrm{h}$

Part (b) Step 1: Given information

We need to find the volume that nurse administer to the child

Part (b) Step 2: Explanation

We know that

The $1 \mathrm{kg}=2.20 \mathrm{lb}$

And as given $1.5 \mathrm{mg}=1 \mathrm{kg}$

And $20 \mathrm{mg}=1 \mathrm{mL}$

Therefore, the volume that nurse administer to the child is, 

$\frac{1 \cancel{\mathrm{kg}}}{2.20 \cancel{\mathrm{lb}}}\times \frac{1 \mathrm{mL}}{20 \cancel{\mathrm{mg}}}\times \frac{1.5 \cancel{\mathrm{mg}}}{1 \cancel{\mathrm{kg}}}\times 72.6 \mathrm{lb}=2.5 \mathrm{mL}$