Updated

Thousands of nurses at nearly three dozen hospitals in Northern and Central California are set to go on strike Thursday over benefit cuts and other concessions sought by hospital management.

The California Nurses Association -- the union organizing the strike -- estimates that nearly 23,000 nurses will walk off the job at 7 a.m. at 33 not-for-profit hospitals run by Kaiser Permanente and Sutter Health, and at the independent Children's Hospital Oakland. The hospitals include Kaiser facilities in Oakland, San Francisco and San Jose, and the Berkeley and Oakland campuses of Alta Bates Summit Medical Center -- a Sutter Health-affiliated hospital.

Sutter Health and Children's Hospital are prepared to bring in replacement nurses, according to officials at each of the hospital groups. Kaiser Permanente says it, too, has made preparations.

The focus of the planned strike is Sutter Health, where contract talks are under way at a number of hospitals.

Management has proposed a broad range of concessions that would affect nurses and patients, union officials say.

"They've taken a very hard line," said Charles Idelson, a spokesman for the California Nurses Association, which is part of National Nurses United.

In addition to asking nurses to accept thousands of dollars in higher costs for their own health care, Sutter's proposed concessions would reduce the ability of certain nurses to advocate for patients, cut pay for newly hired nurses, and slash vacations and holiday pay, the union says.

Idelson said the goal of the strike is to get Sutter to withdraw its "unwarranted and unacceptable concession demands."

Karen Garner, a spokeswoman for Sutter, said the hospital offers its nurses competitive wages and salaries but has an obligation to keep health care costs down for patients.

"The union is choosing to make a sensational statement rather than offer a full picture," she said.

At Children's Hospital Oakland, officials are prepared to bring in replacement nurses and have non-unionized nurses assist with patient care, according to hospital spokeswoman Erin Goldsmith. The hospital, which has roughly 730 unionized nurses, has also rescheduled most elective surgeries, she said.

Union members at Children's Hospital, who have been without a contract for more than a year, have objected to a proposed increase in the cost of a health care plan the hospital offers.

The planned walkout by nurses at Kaiser is intended to show solidarity with other Kaiser employees who are in contract talks and facing demands for cuts in health and retirement benefits, Idelson said. Kaiser Permanente says it is bargaining in good faith and has called the planned nurses' strike "disruptive to patient care and unnecessary."

The strike is scheduled for one day, but Sutter Health and Children's Hospital officials say nurses will not be able to immediately return to work because the hospitals' contracts with replacement agencies require a minimum number of days of service.