AUGUSTA — An official at Riverview Psychiatric Center says specialists brought in to help defuse dangerous situations played a key role in restoring calm Saturday after a patient allegedly used a chair to attack a nurse, leaving her hospitalized with head and eye injuries.

Acting Riverview Superintendent Jay Harper told legislators on Tuesday that the so-called acuity specialists – who are hired to assist with behavior and safety concerns – were sent to the unit where the attack occurred and regained control within minutes. Harper spoke at a joint meeting of the Appropriations and Heath and Human Services committees at the State House.

The hospital, which cares for people with serious and persistent mental illness and substance abuse disorders, had sought funding from the Legislature for four acuity specialists and now has eight of them and is considering adding several more to cover for days off and vacations, Harper said. The acuity specialists replaced corrections officers after a March 2013 incident in which a patient attacked a mental health worker, beating her head and stabbing her with a pen.

The presence of corrections officers and the use of a stun gun on another patient attracted the attention of federal regulators, leading to a survey that ultimately resulted in the loss of certification by the Centers for Medicare and Medicaid Services and the cutoff of federal funding in September 2013. The former superintendent, Mary Louise McEwen, was ousted in March and was replaced by Harper, who recently had retired as a patient advocate there.

The state Department of Health and Human Services has yet to make plans to repay $11 million in federal money it has used to continue to operate Riverview Psychiatric Center since the state hospital lost its certification, and it has an appealed that action, said Ricker Hamilton, deputy commissioner of programs for the department.

“We feel strongly we have a good case and we should never have been decertified in the first place,” Hamilton told legislators on Tuesday. Harper noted that only three units, with a total of 72 beds, are in the request for recertification.

Certification of the 20-bed Lower Saco Unit, where patients have the most behavioral challenges, is not yet being sought.

Harper spoke briefly about Saturday’s incident at the state hospital in Augusta in which Frank Stewart, 23, is accused of aggravated assault in an attack on Nancy Austin, a registered nurse there. Stewart reportedly was angry and refusing to return an aluminum plate to the staff, according to an affidavit by Capitol Police Officer Joseph Morelli.

“This is an unfortunate reality of the work that we do,” Harper said.

The hospital is reviewing the incident and wouldn’t release details of its probe until the middle of next week, Harper said.

Stewart was sent to the hospital in 2012 under a court order after he was found not criminally responsible for assaulting corrections officers at Long Creek Youth Development Center. He had been living in Riverview’s Upper Saco Unit, a longer-term care facility for forensic patients – those sent there through the criminal court system.

Both of Stewart’s psychiatric care providers had retired recently, and he was being treated by temporary providers, according to a report filed May 30 in Kennebec County Superior Court. The report was made in response to Stewart’s request to have community visits supervised by a woman who is a surrogate grandmother rather than Riverview staff. The hospital staff did not support that proposal and had suggested extending his four-hour limit for community events with one-to-one staff supervision and increasing the 10-mile radius from Riverview to which he is limited.

Stewart was taken to the Kennebec County jail after the attack and plans were being made to send him to a mental health unit at the Maine State Prison while the charges are pending.

Also on Tuesday, Sen. Margaret Craven, D-Lewiston, asked why the hospital recently changed the words on the sign in front of the hospital building to “Riverview Psychiatric Recovery Center.” Harper said it was his decision and resulted from monthly meetings with patient groups and reflects the hope of the patients to recover, get jobs and return to their families.

Harper said the hospital is focusing on psychological testing and occupational therapy. “The better they learn it in Riverview, the longer life they will have out of Riverview,” he said.