If a 4-year-old has a live insect trapped in his ear canal causing distress, what should be your first step?

The first step in managing a case where a live insect is trapped in a child's ear canal is to immobilize it with 2% lidocaine placed in the canal. This approach is effective because the insect may be actively moving, causing distress and potential injury to the ear canal. By using lidocaine, you can safely immobilize the insect, minimizing the risk of it moving deeper into the canal or causing further irritation.

Once the insect is immobilized, it can be removed safely without the risk of trauma to the ear structures. This method also helps to alleviate the child’s distress by numbing the area, making the subsequent removal process more comfortable.

Other methods, such as shining a light to coax the insect out, do not guarantee success and could lead to further agitation or movement of the insect deeper into the canal. Removal with tweezers might be inappropriate at this stage because the insect's movement could lead to injury. Sedation with diazepam is unnecessary for this situation and carries risks associated with sedation in young children. Thus, using lidocaine to immobilize the insect is the most appropriate and safe initial step in this scenario.