The chief executive of St. John’s Regional Medical Center in Oxnard, Laurie Eberst, will spend two days a week at St. John’s Pleasant Valley Hospital in Camarillo in the wake of the sudden departure earlier this month of Pleasant Valley President John Bibby. Rather than replace Bibby immediately, the two hospitals will be jointly run by Eberst for the next six months, said Hospital Spokesman Rita O’Connor. After six months, the leadership of Pleasant Valley will be re-evaluated, O’Connor said. Bibby left his post in early November. O’Connor has said in a statement that out of respect for Bibby, she could not elaborate on the reasons for his sudden departure. Both St. John’s Regional and St. John’s Pleasant Valley are owned by San Francisco-based Catholic Healthcare West. The regional medical center in Oxnard has 265 licensed beds while Pleasant Valley in Camarillo has 181. Bibby, formerly head of human resources, was tapped for the presidency in 2010. Eberst, a registered nurse, became CEO of both hospitals in August 2010. She came from Mercy Gilbert Medical Center in Gilbert, AZ, where she served as president for six years.