A hospital may be responsible for physicians actions, depending on the relationship between the physician and the hospital. Generally speaking the hospital is responsible for its employees, whether they be physicians, nurses or other staff members. This liability may be extended to physicians practicing in the hospital not actually employed by the hospital.
Hospital liability for the actions of its employees or agents is called "vicarious liability." IF you believe a hospital may be vicariously liable for harming you, you should speak with a lawyer.