She brings a wealth of health service experience to the role, having been chief executive of Plymouth and Cornwall's primary care trusts before doing the same job in Devon.
The former Plymouth City Council chief executive, who is doing the job for six months, said services and staff could face cuts, but did not specify how much or in which divisions.
Todd announced on Tuesday that he is intending to remain on the board at Plymouth despite being stood down from his role as executive director from 1 January.