Where should an IM injection be administered in an infant?

The vastus lateralis muscle is the recommended site for intramuscular (IM) injections in infants. This muscle is located on the outer part of the thigh and is well developed in infants, making it an ideal site for administering vaccines and medications.

Using the vastus lateralis for IM injections offers several advantages. First, it provides a large muscle mass that can accommodate the volume of the injection without posing a risk of nerve damage, which is a concern with other muscle sites. Additionally, the thigh muscle is accessible and provides ease of positioning, especially in infants who may be squirmy or resistant during the procedure.

In contrast, the deltoid muscle is typically not utilized for infants as it is not sufficiently developed to safely accept IM injections, especially for younger infants. The gluteus medius is also not the preferred site due to the risk of injury to the sciatic nerve and because it is less accessible in infants. Lastly, the abdominal muscles are not suitable for IM injections as they are not a muscle site typically used for this purpose and can lead to complications with absorption and increased discomfort for the infant.