In terms of cross-contamination, you dont want to reinvent the wheel. My best suggestion is that a verbal cue should suffice.
When handing over a patient, the phrase "You have control... " should be followed, in the same breath, with pertinent infomation, in a decending order of importance.
The accepting medical personage should read back that infomation to you, followed by " ...I have control" to ensure it is understood.
This procedure ensures closure and should be followed between theatres.
For a more indepth run-down, contact the Civil Aviation Authority (U.K.) (they're in the phone book) and ask how you can get a hold of the Commercial Pilots' "Human Factors" study material. Flick to the C.R.M. (crew resource managment) section and cross-reference.
Best!