Patient charged over Sydney nurse slashing

A Sydney hospital patient accused of slashing a nurse several times with two knives he found on the ward has been charged.

The man is due to face court on Wednesday after being charged with wounding the nurse, who was caring for him in Blacktown Hospital on Monday night.

The Whalan man, 47, allegedly armed himself began behaving erratically about 10pm on Monday, walking into patients' rooms and taking photos with his mobile phone.

He then armed himself with two knives from the staff room, police say.

When the nurse, who was unaware he was armed, attempted to persuade him to return to his room, he allegedly attacked her with the knives, slashing her wrist and her clothing.

She escaped the staff room before an elderly male patient shut its door and confined the alleged attacker.

The man was charged with wounding with an intent to cause grievous bodily harm. He was refused bail and is expected to appear at Blacktown Local Court.

The Health Services Union said the "sickening" attack highlights the need for specialist security guards.

"Hospital staff go to work each day to care for the public and yet they are being treated as punching bags," HSU NSW secretary Gerard Hayes told AAP.

The union has pushed for 250 extra hospital security officers with "constable powers" since a police officer and a security guard were shot at Nepean Hospital in 2016.

"But all we get is talk," Mr Hayes said.

"It's time for action. Security officers must be employed with special constable powers. That means giving them the autonomy, authority and responsibility."