Certified Medical Assistant (CMA AAMA)PharmacologyMedium
A medical assistant is preparing to administer an immunization to a 6-month-old infant. Which of the following is the most appropriate site for intramuscular injection in this patient?
- AVastus lateralis muscle
- BVentrogluteal site
- CDorsogluteal site
- DDeltoid muscle
Show answer & explanationAnswer & explanation
Correct answer: A. Vastus lateralis muscle
For infants and young children (typically under 2 years), the vastus lateralis muscle in the thigh is the preferred site for intramuscular injections due to its large muscle mass and distance from major nerves and blood vessels.
Why the other options are wrong
- B. The ventrogluteal site can be used for older children and adults but is less preferred for infants.
- C. The dorsogluteal site carries a risk of sciatic nerve damage and is generally not recommended for any IM injections, especially in infants.
- D. The deltoid muscle is not sufficiently developed in infants for routine IM injections.
Infant IM Injection Site
The vastus lateralis muscle is the preferred site for intramuscular injections in infants (birth to 12-18 months) due to its size, accessibility, and lower risk of injury to nerves and blood vessels compared to other sites.
- Located in the middle third of the anterolateral thigh.
- Safest and most developed IM site for infants.
- Deltoid and gluteal muscles are not fully developed in infants.
Memory trick: Infants Love Their Thighs (Vastus Lateralis)