My traveling life has become so much easier since I bought a small portable nebulizer. It is an Omron MicroAir Nebulizer and costs $200, or a little less. It is very small and fits in the cell phone slot in my purse (although it is slightly larger). Also it is completely silent. It operates on batteries. I use lithiums because they last for weeks. The good thing about the nebulizer, as compared to metered doze inhalers, is that you can use as little as you need,
I would tell your husband what is going on and i would probably go to the doctor and get checked out
I might add the folowing, based on the comment your son "is not very stable".
Is the trip to France really necessary? Only you can answer that.
Asthma is a life-threatening condition. People actually die from this diagnosis.
I would be very hesitant about moving this child from an environment where is is under 24/7 surveillance by a watchful mom who knows about what to do and when to do it and where there is generally a six to eight minute wait for a paramedic ambulance in many communities to "somewhere in France"..
Consult with your physician about the adviseability of putting your son on a short duration or oral prednisone. Your husband should, of course carry extra albuterol sulfate and a prescriotion. You might also consult your physician about prescribing Foradil.