BALTIMORE – A pandemic flu outbreak would severely strain many hospitals financially, doctors were told at a seminar Thursday.

Thirty percent of U.S. hospitals currently lose money, with the average hospital having enough cash on hand to meet its needs for 41 days.

A pandemic flu outbreak would fill beds with flu patients instead of those being treated for higher-revenue elective procedures, said Dr. Ken Sands, medical director of health care quality at the Beth Israel Deaconness Medical Center in Boston.

“These are the types of care that usually lead to losses for hospitals,” said Sands, who spoke at continuing education seminar for doctors held at the Johns Hopkins School of Medicine.

Costs for developing and implementing a pandemic flu plan for a 164-bed hospital, meanwhile, is estimated to cost $1 million, Sands said.

The Bush administration has called on states to prepare for a pandemic outbreak and nationwide, state responses have varied.

Almost half of the states have not spent any of their own money yet, relying on federal grants, and little consensus has emerged on whether to close schools or how to ration vaccines and drugs that might be scarce.

William Glezen, a virologist at the Baylor College of Medicine who also attended the seminar, questioned whether the use of vaccines should be reserved for certain groups, such as the young and old, instead of using what’s available early on in an outbreak when they can do the most good.