In the early days of anaesthesia, before the advent of dedicated anaesthetists, it was common practice for a patient's anaesthetic to be administered by the surgeon's houseman. The houseman acted as a technician, the surgeon telling him how to give the anaesthetic, while at the same time operating. There are still a few old diehard surgeons who still try to do this, even with career anaesthetists.
In dentistry it was common practice until the seventies for a single handed dentist to administer an anaesthetic and then perform the dental work.
This concept of a single handed anaesthetist/operator has now long been consigned to the bin marked "unacceptable practices". However the practice has not been abandoned in the DIY sector.
Uh... What kind of work to you do?
3 hours ago