Dr. Shulman was a neurosurgeon at Wilshire Memorial Hospital and was usually in an antagonist role. After reporting Matt Fielding for drug abuse at the hospital, she was mostly seen battling politically with Peter Burns and Michael Mancini.
After the chief-of-staff position came open, Shulman fixed it so that Jonathan Goldberg got the job so they could continue their extra-marital affair. However, when Taylor McBride witnessed them having sex in the parking lot at Kyle's, she told Peter, who confronted Shulman with his knowledge and blackmailed her with the information.
In Season 6, Irene conspired with Peter to have Michael removed from his chief-of-staff position. In season 7, however, she conspired to take both Peter and Michael down by exploiting Eve Cleary's past.
She later led the charge to arrest Peter for embezzlement, but she was witness to the cabin explosion in which Peter and Amanda Woodward faked their deaths.