The rooms, along with a cardiothoracic intensive-care unit, are the first phase of a $95 million project.

Barnes-Jewish Hospital is opening 28 new operating rooms and a 21-bed cardiothoracic intensive-care unit this month in the first phase of a $95 million project that will transform and expand its inpatient-surgery capabilities.

When the project is completed in 2008, the hospital will have 48 spacious new operating rooms to replace 39 older, cramped rooms. The added capacity will be brought into use as volume dictates.

The academic medical center, an affiliate of Washington University Medical School, logs more than 30,000 inpatient and outpatient surgeries a year. That puts it among the top 25 hospitals in the country.

The operating rooms coming on line this month are in what''s called the southwest tower above the Charles F. Knight Emergency and Trauma Center. The new rooms occupy two floors of the tower and will be used primarily for inpatient surgery. The hospital''s 15 ambulatory surgery suites are on the north end of the sprawling Kingshighway campus in the Center for Advanced Medicine.

When the new operating rooms open, the hospital will close older inpatient operating rooms in two waves to make room for 86 recovery rooms and surgical prep beds, a new processing area to sterilize equipment and 20 additional operating rooms.

Dr. Timothy J. Eberlein, the chief surgeon at Barnes-Jewish, said the project is the largest operating-room construction ever undertaken in North America, and the most expensive.

All the new operating rooms will be relatively interchangeable. A room used for open-heart surgery would convert easily for use in a hip replacement, for example. All have the latest technology and monitoring equipment and the flexibility to accommodate future technologies.

The new inpatient operating rooms are a minimum of 600 square feet, compared to 350 square feet in the older rooms. Diane Desmond, a registered nurse and construction project manager, said the additional space will accommodate bulky technology used in micro-surgeries and large imaging equipment, microscopes, lasers and robotics that can be wheeled into place as needed.

Most of the standard equipment, such as oxygen and anesthesia gases and electronic cables, are housed in ceiling-mounted booms.

Mounting equipment overhead keeps the floor open except for the patient''s bed, which is wheeled inside a sterile field that is marked by a circle of contrasting linoleum. Because Barnes-Jewish is a teaching hospital, students are allowed to observe procedures from outside the sterile field.

Each of the new surgery rooms will be equipped with videoconferencing capabilities. Eventually, select surgeries will be broadcast to Washington University medical school classrooms and around the world to allow doctors to observe new techniques and procedures.

Jennifer Arvin, a hospital spokesman, said surgeons and nurses will be able to use the equipment to update family members during long surgeries.

The families can wait in a newly renovated area on the main floor of the hospital that also serves as the entry point for patients arriving for surgery. They will be called using a restaurant-style pager when a surgeon is ready to speak with them or a progress report is available.

Carolyn York, operating-room director, said the hospital went to great lengths to get design input from all its operating room staff. Radiologists, anesthesiologists, nurses, pharmacy personnel - every department that touches the operating room - were consulted to determine details as basic as where to hang the lights and place plugs, she said.