This whole thread just sounds so alien, because in Australia this basically doesn't happen. No one gets terrifying, high bills from a surprise hospital stay https://twitter.com/sarahkliff/status/1075102953470681089 …
Was it at a private hospital? Ambulances are a state-run service and the compensation is weird I think because of the way they were set up historically. If you weren't at a private hospital it's very weird that you had to pay for the anaesthetist