Backcountry asthma
In the backcountry? No question. If the child has a hx of asthma, is having an asthma attack and uses an albuterol MDI and you have a similar MDI available then hand it to the kid, he / she will know what to do. There are MDI's that are NOT 'rescue inhalers' and YOU need to know the difference. (many patients do not). The dosage for an albuterol MDI is not a big issue, without the use of a spacer half the drug is wasted anyway.
Kids die every day from asthma attacks and if he/she cannot break the attack then you may well end up on the wrong side of the curve...
As for other options in the wilderness...
Coffee may help relieve some of the symptoms. Since many attacks are related to allergies an antihistamine may help. In some cases inhaling steam from boiling water will loosen secretions. There is often some combination of mucous buildup and bronchoconstriction. Keep the patient hydrated. Calming measures are very effective. Have the patient focus on slowing their breathing down, taking deeper breaths, holding for a moment then blowing out through pursed lips. Epinephrine from your epi-pen if the symptoms become acute. All of these assume that you have the baseline knowledge and skills to use these interventions appropriately.
If you want to be effective providing medical care in the backcountry then learn the types of medical events that kill (like asthma) and research the drugs and S&S that go along with these medical issues. Become 'informed' beyond your scope of practice and you will make better decisions overall.
As for your question about not doing anything being negligence? You cannot be held liable for choosing not to do something outside of your scope of practice and / or training.
At the poolside, 02 and calming / breathing measures are your choices. Spend some time with someone with chronic asthma and ask them to show you how to talk / calm someone through an attack...
Thanks for all previous replies!
So curious, if you are in the backcountry. Same situation.
Would you give someone else's inhaler to the child?
Would not doing anything to the child be considered negligence? And there's definitely liability if you do give the child someone else's MDI. What would you do?