Some are feeling swamped before they even begin their shifts.
They are increasingly worried about the challenge they face to provide adequate care for high numbers of patients on beds in corridors.
They say patients are staying too long in the department because the wards are too busy to take them.
Deputy chief nursing and midwifery officer Tina Gilbertson confirmed about five emergency department staff had left in the past two months, but said this often happened at this time of the year and the vacancies had been rapidly filled.
New Zealand Nurses Organisation organiser Lorraine Lobb acknowledged nurses in the emergency department were not happy, but pressure on staff was a hospital-wide problem.
Nursing leadership was trying to deal with the issues, but "there is no money".
She believed that core staffing was not right throughout the hospital.
This meant that staff were doing more overtime and some part-time staff were working longer than they wanted to.
Staff on night shift were not taking proper meal breaks and this was becoming the norm, rather than the exception.
Ms Gilbertson said that had been brought to the attention of management and the need to address it was understood.
There was quite a lot of overtime being worked and in the future management would like this to be necessary only in exceptional circumstances.
"However, we accept that in order for this to occur we need to make improvements on our base staffing systems."
Ms Lobb said if staff were getting burned out and leaving then it made it "that much harder for everyone else".
"People working in the hospital are doing the very best for patients that come in, but they are doing it with limited resources".
Ms Gilbertson, in her emailed response to questions, said the recent turnover did impact on nursing staff, but staff continued to work hard to provide an excellent service and management was working hard to support them in that.
Ms Lobb said more attention needed to be paid to work that had been done elsewhere on safe staffing and healthy work places.
It was not a matter of reinventing the wheel and it was not only a nursing problem.
What was not necessarily well recognised was that people who were arriving at hospital were often a lot sicker than in previous times, with multiple health problems.
The hospital's chief operating officer, Vivian Blake, said the department was particularly busy at this time of year and some patients were waiting longer than they should.
This was partly to do with the complexity of the cases which were turning up.
She agreed it was a " whole of systems" issue.
A designated short stay unit for patients who would not need to be admitted, but did require special monitoring, was one possibility the forthcoming virtual analysis of the department would consider.
The hospital needed to be sure that it was a valid option, otherwise it could spend a million dollars which might be better spent on something else.
Throwing more resources and staff into an inefficient system was not the answer.
The simulation modelling would look at a variety of possible scenarios for the department using data already gathered.
The modelling was expected to take about 12 weeks.
