An 18-month-old child presents with a bulging tympanic membrane and fever. After treating for otitis media, what is the next appropriate intervention?

The next appropriate intervention, after treating an 18-month-old child with otitis media, is to reevaluate the patient in 10 days. This follow-up is crucial for assessing whether the treatment has been effective and to determine if any complications have developed or if further treatment is needed.

Otitis media is a common condition in young children and can often resolve on its own or with appropriate medical management. The follow-up visit allows for monitoring the child's condition, providing a chance to check for persistent symptoms such as fever or ear pain, and to assess the tympanic membrane’s status post-treatment. Additionally, this follow-up can help identify if the child is at risk for recurrence or if there may be other underlying issues.

The other options, such as obtaining an EKG or an echocardiogram, are not indicated in this scenario because they relate to cardiovascular assessment, which is not relevant for a straightforward case of otitis media. Referring the patient to a cardiologist is also unnecessary unless there are specific signs or symptoms suggesting a cardiac issue, which are not mentioned here. Therefore, a reevaluation in 10 days is the most appropriate and standard course of action after initial treatment for otitis media in a pediatric patient.