Mandatory overtime has hit a crisis level at St. Boniface Hospital but depending on who you ask, the reason may be the province's overhaul of emergency rooms or a lengthy and difficult flu season.

Manitoba Nurses Union president Sandi Mowat says there have been more mandatory overtime hours logged at St. B. in the first three months of 2018 than all of 2017.

"I do know that a couple of weekends ago there were four nurses that were required to stay for a double shift. And that's a lot," Mowat said. "And that's basically how they're staffing some of these units."

She places the blame squarely on large-scale changes to the health-care system.

The first phase of those changes included the closure of the emergency room at Victoria General Hospital and the urgent care centre at Misericordia Health Centre last October.

"And it's particularly concerning because all the changes that happen at St. Boniface Hospital, all the deletions that happen, one of the rationales we were given for those changes was to decrease the overtime. And so it's interesting to me that it's done the exact opposite," she said.

The numbers the union has are self-reported and will be lower than the official tally, she said.

The spike in mandatory overtime hours is concerning, says Winnipeg Regional Health Authority chief nursing officer Lori Lamont.

But she says a number of factors contributed to it, and the relocation of staff following the changes at other hospitals is just one part.

"One was certainly influenza," Lamont said, adding that in the latter part of December there was a huge spike across the health-care system that impacted St. Boniface as well.

A significant number of admissions to hospital put St. Boniface over capacity, which lasted through January, February and now most of March, she said.

But, Lamont says, the influenza wave is almost over, moving back toward a normal rate.

She also said there's been a spike in the care required for mothers and babies that has challenged staff in the labour and delivery area.

Mowat agreed that's a problem, noting that unit has seen the biggest increase in mandatory overtime — over half the incidents are in that area, she said.

"The problem with that area is you can't decrease the patients. Women are coming in to have their babies, they have to — you can't close beds," she said.

Lamont says St. Boniface has been able to hire 12 new nurses. Of those, seven have been added to the labour and delivery department.

Lamont said the hiring process is ongoing to fill dozens of vacancies.