Surgeries in at least two of Canada's largest hospitals have been cancelled because of bed shortages and other problems that are affecting health-care facilities across the country, administrators say.

Toronto's Sunnybrook Health Sciences Centre cancelled 30 surgeries in December, and more than one-third of the cancellations involved cancer operations.

In an e-mail to staff on Thursday, an administrator at the Ottawa Hospital said the packed emergency department is forcing the "extreme" measure of cancelling surgeries at the last minute.

An overflowing emergency department is among the most visible consequences of a hurting system, according to many doctors and hospital administrators.

They say there is no single reason, although the problem stems in part because of an ongoing lack of beds in nursing homes — which means patients end up using hospital beds — on top of higher demand from flu season.

If people do not leave hospital according to schedule then the holdup reverberates, said Bob Lester, a vice-president at Sunnybrook.

"Only two or three failed discharges can throw our whole scheduling into a mess," said Lester. "It used to be not a problem. It is now enough that we need to look at whether or not we have to cancel surgeries. That's how close we are to capacity."

The capacity issue crops up almost everywhere, said Sharon Shlozberg-Gray, the president of the Canadian Healthcare Association, a federation that represents hospitals across Canada.

"Everyone is trying to be very efficient, have just the right number of beds and resources that we need … averaging through out the year, but it really leaves little flexibility."

The association and hospital administrators agree money will help but won't solve the problems. Adding more beds in nursing and rehabilitation facilities will also make a difference, but won't be a magic solution because the country-wide shortage of nurses means there wouldn't be enough people to provide care.