The nurses need an in-service from your hospital's Risk Management Dept. They aren't home.
Asthmatics sometimes go from wheezing to apneic remarkably quickly.
I would not feel comfortable assuming this boy's life is not in danger. It's fine to work on that, while the patient is being treated. So if all else fails, we have the out of asking whoever brought the child in for permission. This does't solve the problem of the case where the minor comes alone, or with a barely-older sibling. State laws vary.