Mental health services in Canterbury are seeing about 700 more adults and 300 more children and young people per month than before the Canterbury quakes.

A Christchurch mental health worker is warning "someone will be killed" as assaults by patients escalate to an average of more than two a day.

Several staff had suffered such violent assaults they had been off work for more than three months, some for almost a year, a staff member has told Stuff.

A Canterbury District Health Board (CDHB) health and safety report recorded 775 instances of patients across the board physically assaulting staff in 2016, including 82 incidents requiring medical treatment and accepted as an ACC claim.

Two staff working in specialist mental health services in Christchurch, speaking anonymously for fear of repercussions, said they were "appalled at how unsafe" the working conditions were as short-staffed units reached capacity.

"I'm afraid someone is going to get killed," one of them said.

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Patients in the intellectually disabled and forensics units could be particularly violent.

They said the focus on reducing seclusion hours in the past few years had put further pressure on staff already stretched to the limit.

​"Massive staffing issues" including staff off on ACC or sick leave, meant many had to do double shifts and extensions.

"People are on a knife-edge at all times. We are all very concerned. Even patients hide themselves in their rooms. You shouldn't have to do that."

A CDHB spokesperson said most assaults happened in specialist mental health services.

Over the past five years, lost time injuries and injury frequency relating to physical assault had remained static despite increased demand and patient acuity, the report said.

However, the data in the report showed injuries from physical assaults had increased by more than 50 per cent in 2016 compared to 2015.

The number of nurses working in specialist mental health services had increased by about 10 per cent since 2012 but the number of doctors and senior doctors remained stable, despite unprecedented growth in demand for specialist mental health services since the February 2011 earthquake.

Each month, mental health services saw about 700 more adults and 300 more children and young people than before the quakes, the CDHB said in January.

The number of nurses went up from 498 full time equivalents in 2012 to 550 last year, while doctors went from 32 in 2012 to 36 last year and senior doctors from 31 in 2012 to 33 last year.

CDHB general manager mental health Toni Gutschlag​ said the specialist mental health teams worked "exceptionally hard... to provide the best care possible in some very challenging circumstances".

Management and clinicians were "continuously looking for ways to make the environment as safe as possible for consumers and staff".

"Certainly, one assault is one assault too many."

Initiatives to improve safety included a strengthening and increase of clinical leadership, reviews of care models and stabilising staff numbers.

In his February chief executive's update to the CDHB board, David Meates​ said the adult acute inpatient service was at near full capacity in January, with patients required to sleep over in other units to relieve pressure.

He said the workload associated with high numbers of patients was "putting significant pressure on clinical staff and compromising quality".

Mental health units also faced challenges with recruitment of crisis resolution staff and senior doctors, which put "additional pressure on an already busy team".

At the February board meeting, Meates said there were 64 beds in the adult acute inpatient service, but often more than 80 patients in the ward.

Between 14 and 24 patients from the adult acute inpatient service had to "sleep over" in other units for multiple nights each month.

Chief medical officer Sue Nightingale said at the meeting the sleepovers were putting pressure on patients and staff.

"Obviously the patients are vulnerable and feeling unstable anyway – it's very unsatisfactory."



"It's very time-consuming for staff who have to facilitate the sleepovers [on top of their usual work]," she said.