The nurse is scheduled to administer the patient’s next dose of vancomycin at 9:30 a.m. At what time should the nurse draw the patient’s blood to check the trough vancomycin level?

Choice A rationale:

The dorsal gluteal site (also known as the dorsogluteal site) was previously a common injection site, but it's now not recommended due to several significant risks:

Proximity to the sciatic nerve: The sciatic nerve is the largest nerve in the body, and it runs close to the dorsal gluteal site. Accidental injection into or near the nerve can cause severe pain, nerve damage, and potential paralysis.

Difficulty in locating landmarks: The landmarks for the dorsal gluteal site can be difficult to locate accurately, especially in obese patients or those with decreased muscle mass. This increases the risk of injecting into the wrong area.

Risk of injury to blood vessels: The dorsal gluteal site also has a higher risk of injury to blood vessels, as several large vessels run through the area.

Choice B rationale:

The deltoid muscle is located in the upper arm and is a common site for intramuscular injections, but it has limitations for larger volumes:

Small muscle size: The deltoid muscle is relatively small compared to other IM injection sites. It's generally recommended for smaller volumes of medication (up to 1 mL in adults).

Subcutaneous tissue: The deltoid muscle often has a layer of subcutaneous tissue (fat) that can hinder absorption of medication.

Choice C rationale:

The vastus lateralis muscle is the preferred site for intramuscular injections in adults for several reasons:

Large muscle size: It's a large, thick muscle that can accommodate larger volumes of medication (up to 5 mL in adults). Easy to locate landmarks: The landmarks for the vastus lateralis are easy to identify, even in obese patients.

Few major nerves or blood vessels: It has fewer major nerves or blood vessels in the area, reducing the risk of injury. Pain tolerance: It's generally considered to be a less painful injection site than the deltoid or dorsogluteal sites.

Choice D rationale:

The lateral piriformis muscle is not a recognized or recommended site for intramuscular injections. It's a deep muscle located in the buttocks, and injecting into it would be difficult and potentially dangerous due to its proximity to the sciatic nerve and other important structures.

Choice A rationale:

Aspirating prior to injecting enoxaparin is not recommended.

Aspiration was once a common practice to check if a needle had entered a blood vessel.

However, research has shown that aspiration is not necessary for subcutaneous injections and may even be harmful. It can cause pain, bruising, and hematoma formation.

Additionally, aspirating can increase the risk of needlestick injuries.

For these reasons, aspiration is no longer recommended for subcutaneous injections of enoxaparin or other anticoagulants.

Choice B rationale:

Massaging the injection site after administering enoxaparin is not recommended. Massaging can increase the risk of bruising and hematoma formation.

It can also cause the medication to be absorbed too quickly, which can increase the risk of bleeding.

The best practice is to apply gentle pressure to the injection site with a dry gauze pad for a few seconds after the injection. This will help to prevent bleeding and bruising.

Choice C rationale:

The size of the syringe and needle used to administer enoxaparin is not specified in the question. However, a 1-mL syringe with a 32-gauge needle is a common choice for subcutaneous injections.

This size syringe is small enough to be easy to handle, and the 32-gauge needle is thin enough to minimize discomfort.

Choice D rationale:

The abdomen is the preferred site for subcutaneous injections of enoxaparin.

The abdomen has a large surface area of soft tissue, which makes it easy to inject the medication.

The abdomen is also relatively free of blood vessels and nerves, which reduces the risk of bruising, bleeding, and pain. Other potential injection sites for enoxaparin include the upper arms, thighs, and buttocks.

However, the abdomen is generally the preferred site.