As others have mentioned in here, S/L cabin is a big consideration along with safety & reliablity when it comes to medivac retrievals. (Clinic runs are a diff story) All of the above can only be achieved by one airframe that is available new & that's the B200. (4get the P180, not practicable)Not a 'van' & not a PC12.
And rightly so as another member has pointed out some members of the medical farternity won't fly in SE A/C as per union directives for Eg. Was the case down Sth with AAV contract back in 2000 & still is in place, & for good safety reasons.
WMK2
p.s.........yes it's Capt Wally, been re-born after being 'shot down'