A physician ordered magnesium sulfate 2 grams per hour for a maintenance dose. There are 40 grams of magnesium sulfate in 1 liter of lactated Ringers solution.
What is the rate per hour to administer the maintenance dose?

These statements are correct because they follow the guidelines for intradermal injections, which are used for skin testing, such as for allergies or tuberculosis. Intradermal injections are given into the dermis, which is the layer of skin below the epidermis.
The needle is inserted with the bevel of the needle upward at a 10- to 15-degree angle to ensure that the medication is delivered into the dermis and not into the subcutaneous tissue or the epidermis. The bevel is

the slanted part of the needle tip that creates a sharp point. Inserting the needle with the bevel upward also reduces tissue trauma and bleeding.
The inner arm or upper back are the preferred sites for intradermal injections because they have thin skin and minimal hair, which makes it easier to see and measure any reactions. The inner arm is usually used for adults, while the upper back is used for children.
The other statements are not correct because they do not apply to intradermal injections or they contain false information.

a. A depressed area around the injection sites indicates a positive reaction. This statement is false because a depressed area, also known as induration, indicates a negative reaction. A positive reaction is indicated by a raised area, also known as a wheal, that is larger than a certain size depending on the type of test.

b. After the insertion of the needle, a healthcare provider should aspirate for a blood return. This statement does not apply to intradermal injections because aspiration is not necessary for this type of injection. Aspiration is the process of pulling back on the plunger of the syringe to check for blood in the needle before injecting the medication. This is done to avoid injecting into a blood vessel, which can cause adverse effects or reduce the effectiveness of the medication. However, intradermal injections are given into very superficial layers of skin where there are no blood vessels, so aspiration is not required.

The nurse should add 250 mL of water to the formula to dilute it to half strength.

This answer is correct because it is based on a simple ratio and proportion calculation. The nurse can set up a proportion as follows:

250 mL / 1 = x mL / 0.5

Cross-multiplying and solving for x gives:

x = 500 mL

Therefore, the nurse should add 250 mL of water to the formula to make a total volume of 500 mL, which is half the concentration of the original formula.