I remember those asthma days and school -- DS 2 had severe asthma and was able to take needles and adrenilin to the school nurse office. He gave himself the shots in the secretaries office as the nurse office was usually unmanned and the principal was chicken to do it.
The alternative was to call the ambulance and that would have been "too disruptive" for the junior high. He did have other inhalers also. The down size to the inhalers was that some kids kept trying to steal them to get high.
For mild attacks he just lay on the floor until it passed. It is scary for everyone involved. Fortunate puberty eased the problem.