To be honest, no ... I don't understand.
What about emergency surgery?
But more importantly, most (if not all) anaesthetic (or "theatre") ventilators can be run without an anaesthesia machine. Gas supplies need to be consider (that is, be available) - just as they would with an anaesthesia machine - and generally an oxygen-air mixer would be needed. However, as the type (name) implies, anaesthetic (or "theatre") ventilators are generally not suited to use in an ITU situation.
As already mentioned, an anaesthesia machine by itself (without a ventilator) cannot ventilate a patient ... unless you're prepared to have someone sitting there squeezing a rebreathing bag.