A MENTAL health nurse sent to observe a patient was battered repeatedly with a toilet seat.
She suffered a head injury in the incident on November 28 last year, and has not felt well enough to return to work since, Redhill magistrates were told on Friday.
Matthew Hedges, now a patient at Farmfield Hospital in Charlwood, was accompanied in the dock by two medical staff.
He admitted assault occasioning actual bodily harm to Lauren Jackson at the hospital.
Prosecutor Johnson Shittu said the defendant has been a patient in a medium secure unit at the hospital since July 2012.
After a confrontation with another patient, Hedges was restrained by staff.
It was while Ms Jackson was carrying out regular observations on him that the attack took place, the court heard.
Mr Shittu said: "He hit her four times over the head with a toilet seat.
"It caused her to collapse to the floor with blood running from the back of her head.
"She was off work because of her injury and has since not felt well enough to return to work. Mr Hedges attacked a member of staff who was simply carrying out her duties."
Billiejoe Jennings, defending, said: "It is a sad fact of his existence that Mr Hedges suffers manic episodes in a contained environment.
"Quite wrongly in this case a person employed to look after him was a victim of violence.
"It's very sad to hear that the lady has not been able to return to work."
The case was adjourned until August 8 for sentencing at Guildford Crown Court.