In assessing an infant who has been vomiting and is dehydrated, which pulse site is typically checked first?

When assessing an infant, the most appropriate pulse site to check first is the brachial artery. This is because the brachial artery, located in the upper arm, is easily accessible and is the primary site recommended for checking pulse in infants. Due to the anatomical and physiological differences in infants compared to older children and adults, other pulse sites like the carotid or radial arteries may not be as reliable or safe to assess in very young patients.

The brachial pulse is more prominent in newborns and infants, making it easier to palpate. Additionally, it is important to ensure that the infant's circulation is stable, especially in a situation such as dehydration and vomiting, where rapid assessment is critical for effective intervention.

Using less appropriate sites like the carotid or radial arteries could lead to difficulty in obtaining a pulse or misinterpretation of the infant's respiratory and circulatory status. Hence, knowing the correct anatomical site in this scenario, as indicated by the brachial artery, is crucial for effective assessment and responsive action.