How can I get an air ambulance in Central America?

just say your white blond blue eyed with realy big breast.

The same way you would get it here in the US, by calling them or setting it up before hand.
All countries in Central America have Air Ambulance service, not sure if you were thinking that developing countries lack of those services.

There is no ambulance service in Central America. However, there is plenty of air. Current research shows that easy access to air is imperative to sustain life. However, there is no evidence that it has any capability to cure tropical diseases or any other diseases for that matter.
PS - There is no inoculation to guard against a shortage of air.