This has been a fascinating and informative thread and I want to thank all of the contributors for sharing their experiences and advice.
The reason I became interested in this topic is because I dive with someone who does have asthma, well controlled according to her, and she has never encountered any difficulties while I've known her. This includes both while flying and while diving and even during some fairly strenuous and prolonged exertion underwater. But, should she have an episode at 60'....what do I do? What are the proper steps for a dive buddy to take if she does have an attack? I intend to keep diving with her and would, of course, like to be prepared should something occur. Your advice on this would be most welcomed, not just for me but, I think, for all of us who dive.
This is an interesting question. I'm sure the medical experts will chime in at some point... but from a layman Instructors view... I believe it is important at a minimum you verify your buddy has their asthma medication at least on-site... and possibly even with them in the water in a waterproof case.
The thought of bringing an asthmatic in trouble to the surface is scary due to the risk of embolism and over-expansion injury. I don't know if it is realistic to effectively use an albuterol inhaler underwater - but it seems possible since it requires a breath in and then an exhale... So it seems you could take the puff, hold your breath just long enough to get the regulator back in your mouth and do your exhale.
Like I said, I'd like to know what the medical professionals thoughts are on this... but I believe this effort would be safer than bringing them to the surface and then administering the inhaler. Surface administration is of course better than waiting until you get back to the exit point.. which could be too late... so simply having it on site may not be good enough.
During the period for which I thought I had asthma (before just recently finding out I do not,) I always carried my inhaler. From shore based sites I left it at my exit point... and from boats it was always on the boat. In hindsight, I feel this was inadequate preparation. While those I dove with knew I carried an inhaler... it would have done them no good unless they could effectively gotten me back to the boat still alive.
In the end, it is most important that asthmatics dive within their limitations, know their triggers and avoid diving whenever there is a question about their fitness to dive. For you, the dive buddy, I recommend discussing any action to be taken during your dive planning.
In the meantime, are there any diving docs out there that think underwater treatment is a viable option prior to ascent... and if so, what?
Happy Diving...