Washington Hospital Center, the area's largest community hospital, has started a five-year expansion that could see it opening satellite clinics in areas of the District of Columbia and Maryland that have insufficient medical services.

One early step will very likely be the establishment of the area's first major rehabilitation center for victims of accidents, strokes and other illnesses, Samuel Scrivener Jr., president of the hospital's board of trustees, said recently.

Others, he said, could include a new 40-bed extended-care wing for skilled nursing care and new specialty-care clinics.

The program was announced by officials of the giant, 884-bed hospital that last year took care of one hospitalized patient in six in the Washington metropolitan area.

The hospital's wards were nonetheless only 77 per cent occupied, on the average, last year. So hospital officials described their new program as partly a response to unmet medical needs in the area, and partly an essential strategy to keep their hospital filled as new suburban Maryland hospitals are beginning to drain away doctors and patients.

The Hospital Center was still a $76 million operation last year, with that amount in gross revenue, and a $934,014 profit figure at the end of the year, plus a $535,666 added payment from the federal government for 1975 Medicare patients.

It costs the hospital an average of $214 per person a day to take care of its inpatients, a typical figure for a highly specialized hospital.

The officials said they could place no price tag on the new program, though it could run into millions.

"Most of the decisions on precise steps have not been taken yet," Scrivener said.

"But the decisions are now in process," added Judge Samuel Starrett of the United States Tax Court, who is chairman of the trustees' long-range planning committee. "We're not just making sand castles, we're outlining directions in which we will go."

The hospital has in fact moved already in some of these directions. Last month it opened the area's first shock-trauma unit, a center to treat the severely injured that was modeled after Baltimore's Emergency Medicine.

In the past few years, the hospital has started or expanded a nine-bed burn unit for the most serious burn cases, a center for serious skin diseases, a cardiac diagnostic unit and an open-heart surgery program that performed 250 operations last year and forecasts nearly double that number this year.

What the hospital mainly fears, its officials said, is loss of Maryland patients.

In Montgomery County, Suburban Hospital in Bethesda and HOly Cross Hospital in Silver Spring are expanding, and a new Gaithersburg hospital will be built. In Prince George's County, there is a new Lanham hospital, and there will be new ones opening in Clinton and Laurel and possibly Bowie.

With a declining birth rate, obstetric admissions also are falling in every hospital.

"We're a regional hospital," Scrivener said. "We have around $2,000 admissions a year, more than a third of them from Montgomery and Prince George's counties. As a specialized center, we tend to take care of the sicker patients.

"New, smaller hospitals can't possibly duplicate all out services. It will hurt the patient if we can't remain strong."

To that end, he said, the hospital will consider steps in these 11 areas:

Establish new referral and other cooperative relationships with other hospitals.

Start satellite primary care centers - either groups of doctors' offices or clinics - at some of a group [WORD ILLEGIBLE] now being investigated, including an [WORD ILLEGIBLE] supermarket.

Establish more specialty clinics.

Build another doctors' office bulifying adjoining a present one housing 75 doctors on Irving Street NW alongside the main hospital.

Start a 25- to 30-bed rehabilitation center, using present underused areas, rather than building a new wing.

Consider building a 40-or-so-bed extended care wing.

Get the new shock-tramp center firmly established.

Negotiate with area prepaid health plans for possible new business, or start the hospital's own prepaid care group.

Reorganize the medical staff and perhaps add more full-time doctors to improve service and help keep the hospital filled.

Expand marketing and health education programs to inform the public and doctors about Hospital Center services.

Support a merger of the area health planning agencies, the Maryland, Virginia and District agencies that control new hospital building.

Federal health officials for several years tried to get area jurisdictions to join in a single agency, rather than engage in what has become a hospital building race that threatens hospital occupancy throughout the area.

"We strongly favor a single certifying agency," Scrivener said. "We urge District officials and Mr. Califano" - Joseph E. Califano Jr., secretary of Health, Education and Welfare - "to work toward that end."

Other District hospitals, too, have been seeking new roles in the face of increasing suburban Maryland competition. Greater Southeast Hospital is planning a chronic care facility, and Providence Hospital is considering starting a walk-in, walk-out surgery unit in Northwest Washington, among other services.

"We're all facing a period of change," said Richard Loughery, Hospital Center administrator. "What we're talking about is how to make it."