Mullien is your friend. A couple huge doses of strong tincture and some ice on the back of the neck can knock down and asthma attack. Then doses every three hours throughout that day or night. A good maintenance bland for times when asthma is easily triggered is Mullien, yerba Santa and grindelia (gum weed).
I formulated that over the years with a severely asthmatic child. I got her off of all steroids etc and well controlled with these herbs.
That said, if you have attacks, keeping an inhaler around is smart. There is a time and place for pharma meds and I look at rescues inhalers like epi-pens, hopefully you don't need it but this there.
