Where should an IM injection be administered in an infant?

The vastus lateralis is the preferred site for intramuscular (IM) injections in infants due to its size and location. This muscle is located on the outer thigh and is well-developed in infants, making it a safe and effective injection site. Additionally, using this area reduces the risk of injury to nerves and blood vessels, which are more densely located in other areas like the deltoid or gluteus medius. The vastus lateralis is also more accessible and allows for proper absorption of the medication.

In contrast, using the deltoid muscle is generally reserved for older children and adults, as it may not be sufficiently developed in infants. The gluteus medius is not recommended for infants due to the risk of hitting the sciatic nerve, and the abdominal muscles are not appropriate for IM injections as they are not designed for this purpose. Therefore, the vastus lateralis stands out as the safest and most effective site for administering IM injections in infants.