A former nurse from Superior, Wis., admitted Wednesday that she sneaked into a Coon Rapids hospital last May and siphoned painkilling medications out of patients' IV bags to feed her own addiction.

Maria A. Mihalik, 27, pleaded guilty in federal court in Minneapolis to entering Mercy Hospital on May 5, when she was still a licensed registered nurse, and posing as an employee to steal the morphine derivative hydromorphone hydrochloride.

Mihalik faces a maximum sentence of four years in prison. A sentencing date has not been set.

Soon after the allegations against Mihalik came to light, the Minnesota Board of Nursing pulled her nursing privileges. Wisconsin revoked her license in October.

"She's done what she can do to accept responsibility and completed treatment," said Mihalik's attorney, Robert Lengeling. "She has no intention to return to nursing at this point."

The Anoka County Sheriff's Office said at the time of her arrest that Mihalik impersonated a nursing student and stole the painkiller from at least three patients at Mercy. She was arrested at the hospital, wearing nurse's scrubs, while trying to flee, the sheriff's office said.

Hospital officials found three IV bags had been punctured or tampered with, and Mihalik had syringes in her possession with a clear fluid in them, according to the sheriff's office.

The hospital said no patients were harmed.

Mihalik had been working at St. Mary's Medical Center in Duluth until March 26, 2010, and that hospital investigated her for allegedly tampering with patient medication in early April, Duluth police said. She ended up being ticketed for trespassing and resigned from St. Mary's, her attorney said.

Mihalik graduated with honors from Wisconsin Indianhead Technical College in 2004, receiving an associate degree in nursing, a school official said. She was first licensed in Wisconsin as a registered nurse in June 2004 and was cleared to start work in Minnesota later that year.

Paul Walsh • 612-673-4482