Ambulances were used as makeshift emergency rooms at North Shore Hospital yesterday as the emergency department struggled to cope with an influx of patients.
Rachel Haggerty, general manager of adult health services at Waitemata District Health Board, said there was an unusually high number of patients soon after midday, stretching staff and facilities for much of the afternoon.
It was decided to hold the less serious casualties in ambulances while the more serious cases were admitted as usual.
"It's never an ideal situation for anybody, but ... ambulance officers are there monitoring the patients. It's not an unsafe situation."
In one case, the family of an elderly woman who had had an asthma attack took her home after having to wait in an ambulance for attention.
Another man, apparently frustrated, discharged himself from an ambulance despite staff's attempts to dissuade him.
Ms Haggerty said the case of the elderly woman would be investigated.
Early afternoons were always busy - particularly during weekends - but there appeared to be no obvious reason why yesterday was so busy.
Patient numbers at the hospital often stretched staffing levels.
"We are very stretched so little variations like this will occur and these are the decisions we have to make."
Ambulance control was in touch with the hospital and vehicles would have been released where necessary for emergencies.
Ms Haggerty said the backlog of patients was cleared soon after 4pm.