KEY POINTS:
Auckland City Hospital's emergency department was so busy this week that it went on"purple alert" - a previously undisclosed level of patient-overload warning.
And Middlemore Hospital emergency had its busiest day of the year, a load comparable to last year's record.
Many hospitals use yellow, orange and red alerts to describe how crowded they are with sick and injured and to let staff know what must be done to free beds or speed the flow of patients.
But it emerged this week that Auckland City Hospital's emergency department has purple alert in reserve for its most overloaded times - when it is close to using its last patient space and measures must be taken, such as cancelling teaching and calling all available staff in.
It went on purple alert for three hours from 9.30pm on Wednesday.
The department's clinical director, Dr Tim Parke, said yesterday this meant some patients brought in by ambulance had to wait in the triage (assessment) area for up to an hour for space to be made for them.
"No one was put at serious risk. They were assessed by St John Ambulance and by the triage staff and constantly monitored."
They were "lower acuity" patients - assessed as triage level three or below on a scale of one to five.
"The point of Code Purple is to prevent diversion of ambulances to other hospitals, which we will never do, and to prevent putting patients in corridors, which we've said we won't do."
Dr Parke said the only other time purple alert had been used was two years ago, when the policy was first written, at a time when the department was extremely busy during an influenza outbreak.
The hospital's inpatient wards have been on red alert and at, or above, 98 per cent occupancy for much of the week, reflecting the influx of patient at other hospitals.
Middlemore's service manager for acute care and resources, Dot McKeen, said the hospital had been running at 98-99 per cent and sometimes higher while patients were being admitted and others were completing the discharge process.
On Monday, 264 people were seen at the emergency department, the highest tally for the year.
"We had 196 people in the ED who had come to us not via a doctor but just self-presented. It's the usual message ... if people go to a GP, the GP can screen who needs to be seen in hospital and can deal with a lot of the cases themselves."
