The longtime leader of the firm that owns troubled Shady Grove Adventist Hospital in Rockville will retire next week and be replaced by executives on loan from another regional hospital system controlled by the Seventh-day Adventist Church.

Ronald M. Wisbey, 63, will step down Tuesday as interim chief executive officer of Adventist HealthCare Inc. and hand control to Robert Henderschedt and other managers from Adventist Health Systems, an Orlando-based firm that runs 34 hospitals.

The new team will be in charge for 90 days or until people are appointed to fill a number of key vacancies. At Adventist HealthCare, those openings include board chairman, chief executive officer and chief financial officer, and at Shady Grove they include president, nursing director and quality assurance director.

Wisbey's abrupt retirement comes as the hospital appeals a decision in November to downgrade its accreditation status and urges federal and state officials not to end Medicare funding at the 263-bed hospital.

The regulatory problems arose after the Shady Grove medical staff protested persistent management and patient care problems. The mistakes included medication errors, an operation performed on a patient's wrong hip and the death of a severely ill patient who was left unattended in a hallway.

Kim Humphrey, the director of quality assurance at Shady Grove, resigned on Thursday. She and Adventist HealthCare spokesman Robert Jepson declined to comment on the move yesterday.

Wisbey said the time is right for him to close out a 42-year career with the church and later the hospital company that runs Shady Grove Adventist, Washington Adventist Hospital in Takoma Park, a string of nursing homes and other health care properties in the region.

"My wife and I have planned for this for a long time," he said yesterday. "It appears to us that this is a good time in the life of this company as well as in our own, so we are very anxious for it now."

Jepson said the company is enthusiastic about the hiring of Henderschedt, who is senior vice president of administration at the Florida company. He will be accompanied by Mardian Blair, the recently retired CEO of the same company.

"They are a large and diverse organization," Jepson said. "They bring additional management expertise to Adventist HealthCare, which is particularly important at this time."

Adventist HealthCare has 5,000 employees in Maryland, the District, Virginia and New Jersey. In 1998, the nonprofit firm reported revenue of $314 million and a $19.4 million surplus.

The management turmoil began in October, when the medical staff's complaints became public. On Nov. 3, Adventist HealthCare board members forced the company's chief executive, Corey Chambers, to resign and reassigned another top executive.

On an interim basis, Adventist brought in a new board chairman, church official Harold Lee, and Wisbey moved from board chairman to interim chief executive. Executive compensation also became an issue in recent months. In 1997, Adventist HealthCare CEO Bryan Breckenridge received a $4.7 million severance package, and chief financial officer Edmund R. Peters left soon after with a severance package worth $3.1 million.

Jepson offered no information on Wisbey's retirement package. Wisbey's compensation was $364,000 in 1998, including retirement benefits, deferred compensation and other benefits.

CAPTION: Ronald Wisbey will retire Tuesday as interim CEO of Adventist HealthCare.