aving O2 canisters in place for the four airports in question (or five) is a logistical nightmare.
True, but could anyone comment on what would happen if, say, midway between SXM & CUR, the passenger starts having a seizure?
Given what was stated in the article, is the chance of that not almost 1?
Firstly, that is a terrible thing to inflict on the other passengers. Secondly, what is the procedure for treating, and who does it? What equipment is needed and how much space is needed? Presumably a "lessor" airline would just refuse to take the passenger?
Now if it gets more serious, where do you divert to? At least if this trip was to Florida, there would be a number of major cities up the east coast with specialist childrens' units that could help (but at what cost?). The Caribbean is a nightmare in this respect - different jurisdictions and very different standards of facilities as the populations on each island simply don't warrant the existence of the kind of facility you would find in a hospital like, say Great Ormond St. And that, of course, is assuming they will let you park your 747-400 there in the first place!