Similar advice applies for Central Africa
Having just seen this thread, I'm very pleased to see that the correct advice was offered to the enquirer and that it worked.
Here in Central Africa, we suggest that a stretcher-patient can be flown on a commercial flight when 6 seats are blocked out, so that there is space for the patient, flight-doctor,flight-nurse and 1 relative.
For the air-ambulance it's best to have travel-insurance as it is pricey.
From remote areas the air-ambulance is often the only option " Because every life counts", which is our motto.
I started a similar thread in Africa Aviation in a effort to elicit awareness of the existance of the various air-ambulance services and response was only luke-warm. Go figure?