Serena Campbell is a fictional character from the BBC medical drama Holby City, played by Catherine Russell. She first appeared in the fourteenth series episode "Coercion", broadcast on 1 May 2012. Serena is a consultant general surgeon and formerly Holby General Hospital's deputy CEO. She was introduced along with two other regular characters by the show's then executive producer Johnathan Young, who wanted more "truthful and complicated" characters in the series. Serena was originally Frankie Renard, but the name was changed as the producers thought it was "terrible". Russell auditioned for the role and attended a second call back where she was made up in Serena's costume and make-up. After being cast, the actress was given advice about Serena's profession from a female surgeon to help her prepare for the part. Aspects of Russell's personality traits were incorporated into the character of Serena after she was cast.

Henrik Hanssen is a fictional character from the BBC medical drama Holby City, played by actor Guy Henry. He made his first appearance in the thirteenth series episode "Shifts", broadcast on 19 October 2010. Hanssen is initially a consultant general surgeon and the joint Director of Surgery of Holby City Hospital. He later becomes the sole Director of Surgery and the chief executive officer of the hospital trust. Henry has also appeared in Holby City's sister show, Casualty, as Hanssen on multiple occasions.