Wellington Hospital is being stretched by winter sickness, with some emergency department patients waiting more than six hours for a bed.
Some staff have expressed concern about patient safety in the face of the strain in the past week.
"It's not safe for patients or staff," one source said.
Capital & Coast District Health Board chief medical officer Geoff Robinson yesterday confirmed there had been a jump in the number of people turning up at the emergency department, most of them with flu, in the past week.
But Robinson said that the increase was normal, if late, for winter, and the hospital was managing far more effectively than in previous winters.
"Flu season has arrived a month later than usual, but it is no different to what we would usually expect at this time of year."
In previous years the hospital had consistently had more patients than beds in winter but it had rarely run out of beds this year.
This was despite a jump in the number of patients, with 128 more people turning up at the emergency department in June compared with the same month last year.
The hospital had dealt with more than nine out of 10 patients within six hours - a Government-imposed target for all DHBs - in June, far better than four years ago when nearly a quarter of all patients waited for more than six hours, he said.
This was largely down to better management of patients throughout the hospital and about 18 extra ward beds being added last August.
"In terms of capacity and patient flow, we have come a long way."
High rates of flu have already strained some hospitals in Auckland, with Waitakere and North Shore hospitals reportedly forced to put off elective surgeries last week because a shortage of beds.
National flu figures - collected by Environmental Science & Research (ESR) - show Wellington has escaped the worst of the season so far, which has hit hardest in Auckland and South Canterbury.
But Capital & Coast still reported 22 cases last week. Within the lower North Island, flu rates were highest in Wairarapa.
Although flu rates already exceed last year's quiet winter, they remained relatively subdued.
However, Google's flu trends - which the company says tend to reflect flu levels, based on what Kiwi are searching online - are at their highest rate in six years.
- The Dominion Post