What is the name of the character who has a son named Louis and has been played by the same actor since the series' inception?
Exile (Casualty):  The plot sees Charlie Fairhead (Derek Thompson) and Connie Beauchamp (Amanda Mealing) travel to Bucharest to help Charlie's son Louis (Gregory Foreman), who has become a heroin addict and is planning on selling his kidney to pay his debts. Derek Thompson (actor):  Thompson has played the role since the series' inception in 1986.
Charlie Fairhead