Fifteen months after the state government promised to tackle sky-rocketing rates of drug-induced violence in emergency departments, 30 new security guards have been hired, well short of the 300-person shortfall identified by the Health Services Union.

On Friday, a female nurse was allegedly taken hostage by Craig Matthew Moore, 28, who came into Wyong Hospital's triage section at about 5.15pm demanding to see a psychiatrist.

He allegedly held a knife to her throat and warned security guards to get out, it's understood.

After a tense stand-off, a male nurse convinced Mr Moore to restrain him in exchange for his female colleague.

Eventually, Mr Moore released his grip on the male nurse and a hospital security guard was able to pull him to safety.

A Traffic & Highway Patrol Command officer who was first on the scene was able to convince Mr Moore to drop the knife. He was then medicated and placed in a hospital bed.

On Monday, NSW HSU secretary Gerard Hayes said they had been asking for the number of permanent guards at Wyong Hospital to increase from three to four for 12 months.

"Security in hospitals is chronically understaffed and under-resourced," he said. "We have been arguing for more security officers until we are blue in the face."

One of the 30 new security guards went to the Central Coast local health district but was taken by Gosford Hospital. District chief executive, Dr Andrew Montague, said a review of security measures at Wyong was under way but an additional guard wouldn't have prevented the hostage incident.

Wyong Hospital was one of 20 hospitals earmarked for an emergency department security audit by the state government after a near-fatal incident in Nepean Hospital's emergency ward in January 2016.

In that incident, ice addict Michael de Guzman allegedly held a pair of scissors to the throat of a female doctor then scuffled with police officer Luke Warburton and security guard Barry Jennings, allegedly shooting both in the legs when he grabbed Mr Warburton's gun from its holster. He has pleaded not guilty.

Then health minister Jillian Skinner responded with a 12-point action plan but only six have since been implemented, a NSW Health spokeswoman said on Monday.

"Significant progress [has been] made on the other six. The remaining action items are those that require substantial work [like] legislative change and new IT systems," she said.

Measures that have been implemented include a new TAFE course to upskill guards and staff training for dealing with aggressive patients. Staff at Wyong Hospital say the training is slow and expected to take years to reach everyone.

A working group that was established following the Nepean Hospital incident meets regularly but Mr Hayes said he stopped attending because it had become so bureaucratic that "it wasn't worth wasting my time".

Health Minister Brad Hazzard said he had requested a full briefing on the Wyong incident and an update from all 15 local health districts on their progress with the 12-point plan.

He said he spoke to the Wyong nurses on Saturday and praised their heroic actions.

"Both nurses were obviously brave but [the male nurse] was incredible in so far as he offered himself up to be substituted," he said.

Mr Moore was refused bail in Wyong Local Court on charges of take and detain for advantage and use offensive weapon with intent to commit indictable offence.